RADIO ASTRONOMY / VLBI

Research Highlights

Here we show recent research results from the Radio Astronomy/Very-Long-Baseline Interferometry department.

List of refereed papers from the Radio Astronomy/VLBI department (ADS public library)

ERC advanced grant for Prof. Dr. Yuri Kovalev

ERC advanced grant for Prof. Dr. Yuri Kovalev

April 11, 2024
Classical telescopes and neutrino telescopes will allow scientists to understand extreme cosmic super-colliders more

Understanding AGN jets with the TELAMON programme

28 March 2024

A paper published today shows the results obtained by a team led by Florian Eppel, including scientists from the MPIfR and the University of Würzburg, reporting on the first results from the TELAMON program (PI. M. Kadler).  The TELAMON programme uses the 100 m Effelsberg telescope to monitor radio spectra of active galactic nuclei (AGN), in particular TeV blazars and neutrino-associated AGN. This study focuses on the characterisation of a main sample of TeV-detected blazars. Data from about 2.5 years of observations were analysed, covering frequencies from 14 GHz to 45 GHz. In the pilot phase, 59 TeV-detected blazars in the northern hemisphere were observed. Basic data reduction and calibration procedures were applied to the TELAMON data, and an averaging method was used to compute mean light curves for the sources. The results show that TeV-selected blazars in the sample typically have a flat radio spectrum, with a median spectral index of -0.11. These results are consistent with previous studies of TeV-selected blazars. Compared to the GeV-selected sample, the TELAMON sources have a lower radio flux density, which is consistent with the spectral characteristics of TeV-emitting blazars. The spectral index distribution of the TeV-selected blazar sample is similar to that of the GeV-selected samples. In addition, a strategy for tracking the light curve evolution is presented for future variability and correlation analysis.  More details can be found in the publication, appeared today in Astronomy & Astrophysics, here.

Sagittarius A*

Sagittarius A*

March 27, 2024
Astronomers Unveil Strong Magnetic Fields Spiraling at the Edge of Milky Way’s Central Black Hole more

Selected media echo and parallel press releases (Sgr A* 2017 EHT polarisation image release)

Parallel Press Releases:

English:

Spanish:

German press echo here (VLBI Department Highlights German version)

Magnetic launching of black hole jets in Perseus A

Magnetic launching of black hole jets in Perseus A

February 01, 2024
First observations of the radio galaxy Perseus A with the Event Horizon Telescope more

Selected media echo and parallel press releases (Perseus A 2017 EHT image release)

English:

 

New EHT observations of M87 reveal persistent black hole shadow

New EHT observations of M87 reveal persistent black hole shadow

January 18, 2024
Improved observations one year after the discovery image give a better picture more

Selected media echo and parallel press releases (M87 2018 EHT image release)

Here selected parallel press releases and news & views on the A&A publication of the Messier 87* images by the Event Horizon Telescope from observations in 2018.

English:

German:

Spanish:

Unraveling Blazar Mysteries: TANAMI's First-epoch S Band Images

16 January 2024

A team of astronomers led by the MPIfR PhD candidate Petra Benke presents a new publication on southern radio sources. The study focuses on the multi-wavelength emission from blazars, which are celestial objects that emit radiation across the electromagnetic spectrum, from radio to high-energy gamma rays. Recent successes in the study of blazar activity have come from quasi-simultaneous multi-wavelength monitoring programs made possible by the launch of the Fermi Gamma-ray Space Telescope in 2008. The team used VLBI to carry out sensitive, long-term monitoring of a comprehensive sample of gamma-energetic AGN. These observations were made with the Long Baseline Array (LBA) and other radio telescopes in the Southern Hemisphere at 13 cm wavelength (S-band) as part of the TANAMI program. The study presents the first light TANAMI S-band images, highlighting the TeV-detected sub-sample of the full TANAMI sample. The analysis examines the redshift, 0.1-100 GeV photon flux, and S-band core brightness temperature distributions of the TeV-detected objects. In particular, flat-spectrum radio quasars and low-synchrotron-peak sources have on average higher brightness temperatures than high-synchrotron-peak BL Lacs. In addition, sources with bright GeV gamma-ray emission show higher brightness temperatures compared to gamma-low sources. More details of the study can be found in the original paper here (preprint here).
 

Unveiling the Dynamic Landscape of BL Lacertae's Jet: First GMVA Observations with Upgraded NOEMA Facility

12 December 2023

In a study published today in the journal Astronomy & Astrophysics, a team of MPIfR astronomers led by Daewon Kim presents a comprehensive analysis of a single epoch Global mm-VLBI Array (GMVA) observation of the blazar BL Lacertae (BL Lac) at 3.5 mm wavelength in April 2021. In particular, the upgraded Northern Extended Millimetre Array (NOEMA) significantly increases the sensitivity of the GMVA, allowing it to image BL Lac during an unusually robust γ-ray flare.  To gain meaningful insights into the inner subsecond jet of BL Lac and to assess the impact of NOEMA's contribution, the team used advanced data reduction techniques (including the pipeline rPICARD developed by MPIfR-affiliated scientist Michael Janssen) which yielded high-fidelity VLBI images.  These results indicate a 2.5-fold improvement in image sensitivity with the inclusion of NOEMA. The jet exhibits a pronounced wiggling structure within the central parsec-scale of the core with a helical jet structure showing a sinusoidal pattern. Model fitting to the inner jet region reveals up to six features, the two innermost of which are very bright and compact, suggesting significant relativistic beaming.  In addition, these observations reveal four prominent polarised nodes in the jet, two of which are located in the core region. This intriguing discovery prompts consideration of different physical scenarios to interpret the observations. This study represents a significant advance in the understanding of the dynamic nature of the BL Lacertae jet and opens avenues for further exploration and theoretical modelling.  For more information, see the original publication here.

A computer simulation of a disk of plasma around the supermassive black hole at the center of the M87 galaxy. A new analysis of the circularly polarized, or spiraling light, in EHT observations shows that magnetic fields near the black hole are strong. These magnetic fields push back on infalling matter and help launch jets of matter at velocities near the speed of light out. Image Credit: George Wong

A supermassive black hole’s strong magnetic fields are revealed in a new light

November 08, 2023
New M87* results from the Event Horizon Telescope more
Astronomers capture formation of a powerful cosmic jet

Astronomers capture formation of a powerful cosmic jet

October 26, 2023
A telescope larger than the Earth has found a plasma rope in the Universe more

Selected Media Echo (RadioAstron Observations of 3C 279)

Some highlighted articles, for a complete picture, see the MPIfR web area here.

Helical structures in the cosmic fountain emanating from Messier 87

09 October 2023

A team of researchers led by the MPIfR PhD candidate Alexei Nikonov has revealed intricate details of the cosmic jet within galaxy M87. Utilizing advanced technology, the team conducted high-resolution radio observations at 8 and 15 GHz over three consecutive days in May 2009, employing the VLBA, VLA, and Effelsberg 100 m telescope.  The resulting images, boasting dynamic ranges exceeding 20,000:1, disclosed a limb-brightened jet and a subtle counter-jet with a steep spectrum. Analysis of the jet-to-counter-jet ratio facilitated the estimation of key physical parameters. Notably, the internal structure of the jet revealed three helical threads, indicative of Kelvin-Helmholtz instability in a supersonic flow with a Mach number of approximately 20 and an enthalpy ratio of around 0.3.  A spectral index image generated at 8-15 GHz demonstrated spectrum flattening at the intersections of these helical threads, reinforcing the Kelvin-Helmholtz origin of the observed internal structure. Additional findings include the detection of polarized emission in the jet, Faraday rotation with a transverse gradient, and the presence of a helical magnetic field. Our study provides a comprehensive exploration of M87's cosmic jet, shedding light on its complex dynamics and contributing valuable insights to the field of astrophysics.  More details can be found in the original publication at the Monthly Notices of the Royal Astronomical Society here.

Second Workshop on German Science Opportunities for the ngVLA

Second Workshop on German Science Opportunities for the ngVLA

Following the first conference last December, a second conference was held on September 27-28 at the Max Planck Institute for Mathematics in the Sciences in Leipzig, Germany. The goal was to discuss the interests of the German community in ngVLA science and opportunities.  The meeting was co-organised by the MPI für Radioastronomie, who also supported lunch and coffee breaks.
The conference was followed by an Open Day event organized by mtex antenna technology and NRAO. mtex antenna technology has been contracted to design, develop, and produce the 18m ngVLA prototype antenna. Open Day participants were briefed on the prototype antenna's cutting edge technology and the ngVLA project's overall status. Portions of the prototype antenna were then unveiled to an excited crowd of government and business leaders, scientists, engineers, and the press from Germany and the US. more

Monitoring of radio galaxy M87 confirms black hole rotation

26 September 2023

Schematic representation of the tilted accretion disk model in M87

The nearby radio galaxy M87, located 55 million light-years from the Earth and harboring a black hole 6.5 billion times more massive than the Sun, exhibits an oscillating jet that swings up and down with an amplitude of about 10 degrees, confirming the black hole's spin.

The study, which was headed by Chinese researcher Dr. Cui Yuzhu and published in Nature on Sept. 27, was conducted by an international team using a global network of radio telescopes, including RuSen Lu and Jae-Young Kim, affiliated to the MPI für Radioastronomie.

Through extensive analysis of telescope data from 2000­–2022, the research team revealed a recurring 11-year cycle in the precessional motion of the jet base, as predicted by Einstein's General Theory of Relativity. The study links the dynamics of the jet with the central supermassive black hole, offering evidence that M87's black hole spins.  More information can be found at the Nature paper cited above.

A Smoking Gun for  Supermassive Binaries in Active Galactic Nuclei

A Smoking Gun for  Supermassive Binaries in Active Galactic Nuclei

August 31, 2023
Blazar Jet Variability probes precession caused by orbiting black holes in the centers of galaxies more

From hero to zero: the binary hypothesis for the quasar PSO J1134.2028+1.4075

24 August 2023

A study led by MPIfR PhD student Petra Benke, published today in the journal Astronomy & Astrophysics, takes a closer look at the enigmatic quasar PSO J334.2028+1.4075 (PSO J334). Initially thought to be a supermassive black hole (SMBH) binary system, the quasar's optical light curve showed periodic flux density variations. However, subsequent observations with the European Very Long Baseline Interferometry Network (EVN) and the Karl G. Jansky Very Large Array (VLA) provide a clearer picture: the source has a single parsec-scale radio feature, a kiloparsec-scale lobe-dominated quasar, and a possible precessing jet. Contrary to previous binary hypotheses, the evidence suggests that PSO J334 is a jetted active galactic nucleus with a single SMBH, rejecting the idea of a binary system in its central engine. The study highlights the importance of detailed radio analysis in understanding the complex structures of distant quasars.  More details can be found in the original publication here.

A further success of the space-VLBI RadioAstron mission: discovery of a mini-cocoon around the restarted parsec-scale jet in 3C 84

17 August 2023

In the current issue publication in The Astrophysical Journal, an international team researchers led by Tuomas K. Savolainen from Aalto University, also affiliated to the MPIfR, unveiled a remarkable finding in the galaxy 3C 84. Utilizing space-VLBI observations, they detected a mini-cocoon surrounding a reactivated parsec-scale jet. These observations, conducted with a global array of radio telescopes, provided unprecedented resolution, revealing intricate sub-structures within the jet. Most notably, the 5 GHz image revealed low-intensity emissions from the cocoon-like structure, suggesting that the jet's increased power inflates a hot plasma bubble as it traverses the galaxy's central region. The study estimates the mini-cocoon's energy, pressure, volume, and its impact on the interstellar medium. The findings indicate that a significant portion of the jet's energy is transferred to this mini-cocoon, and its quasi-spherical shape influences the energy distribution in the surrounding medium, shedding new light on the dynamics of radio galaxies. This discovery has the potential to reshape our understanding of cosmic processes and will undoubtedly stimulate further exploration and discussion in the field of astrophysics.  More information, at the original publication here.

Space-VLBI to probe the compactness of the central region of M87 at 13 mm wavelength

14 July 2023

RadioAstron has observed the central region of the well-known elliptical galaxy M 87, by  using state-of-the-art 22 GHz space-VLBI in the framework of the RadioAstron mission.  As part of the Nearby AGN Key Science Program, the galaxy was observed in February 2014. These observations, involving 21 ground stations and extending to Earth-sized projections, resulted in spatial resolutions as fine as 20 Schwarzschild radii, equivalent to a mere 150 microarcseconds. This probed details of the core region previously concealed.  The most remarkable revelation is the identification of an extraordinarily high brightness temperature, surpassing 1012 K. This unexpected finding challenges existing theoretical frameworks and prompts astronomers to explore unconventional explanations, such as extreme Doppler boosting, unique jet perspectives, or novel particle acceleration mechanisms.  This work, led by Jae-Young Kim from Kyungpook National University and also affiliated to the MPIfR are presented in the current issue of The Astrophysical Journal.  More information can be found in the original publication here.  

 

MOEA/D: A Novel Approach to Radio Astronomy Imaging


30 June 2023

In the vast realm of radio astronomy, image reconstruction remains an intricate puzzle. Despite the rising sensitivity and capabilities of telescopes, the challenge of solving this ill-posed inverse problem persists. Recent breakthroughs have introduced innovative algorithms, featuring constrained nonlinear optimization and Bayesian inference, as potential solutions.  The Event Horizon Telescope (EHT) Collaboration's endeavors in scrutinizing image reconstructions have offered valuable insights. Yet, when dealing with active galactic nuclei, existing methods encounter a time-consuming obstacle: the need for large and expensive surveys, each with different optimization parameters.  In a new publication led by the MPIfR researcher Hendrik Müller, together with Alejandro Mus from the Universitat de València in Spain and Andrei Lobanov from the MPIfR, they present a groundbreaking solution – a nonconvex, multiobjective optimization approach that opens new avenues.  Their methodology leverages a multiobjective version of the genetic algorithm, known as MOEA/D. This genetic algorithm explores the objective function through evolutionary operations, identifying various local minima while avoiding the pitfalls of saddle points.  These experiments, utilizing synthetic data based on the 2017 EHT array and a potential future EHT configuration, demonstrate the power of MOEA/D. We successfully unveil a complete Pareto front of nondominated solutions, showcasing the diverse image morphologies. The publication discuss strategies for identifying the most natural guess among these solutions and put it to the test using synthetic data. Finally, they apply MOEA/D to observe the black hole shadow in Messier 87 with the 2017 EHT data.  In conclusion, MOEA/D proves to be a flexible and efficient tool, outperforming Bayesian methods in terms of speed and solution exploration. This research comprises the first of two papers, with the first explaining the fundamentals of multiobjective optimization and MOEA/D while demonstrating its capabilities in recovering static images. A further publication will extends the algorithm's utility, enabling dynamic and polarimetric reconstructions, both static and dynamic.  More details about the present publication, at the current issue of Astronomy & Astrophysics, is available here.

DoG-HiT: A Breakthrough in High-Resolution Imaging

24 May 2023

A substantial change forward is underway in the field of Very Long Baseline Interferometry (VLBI). With a limited number of antennas and constrained observing time, imaging cosmic phenomena with precision has always been a challenge. However, recent innovations in multiscalar imaging, such as the DoG-HiT method, have changed the game. Known for their speed, accuracy and unbiased performance, these techniques address the sparsity problem in Fourier domain sampling. In a publication written by the MPIfR scientists Hendrik Müller and Andrei P. Lobanov, they introduce a multiscalar approach that extends to polarimetric imaging, dynamically evolving sources, and dynamic polarimetric reconstructions, aptly named "mr-support imaging". By using wavelet transforms and a set of statistically significant coefficients as priors, we've achieved remarkable results. Synthetic data tests with the Event Horizon Telescope (EHT) demonstrate the power of mr-support imaging, providing a rich regularisation for complex dynamics at the event horizon scale.  Looking ahead, the ngEHT extension promises even more exciting opportunities for dynamic polarimetric reconstructions. As instruments continue to evolve, the potential to observe dynamically evolving patterns in unprecedented detail grows. This work introduces a simpler but effective regulariser, multiresolution support, to the arsenal of dynamic reconstruction methods. More details can be found at the present issue of Astronomy & Astrophysics, here.

How the black hole in M87 launches a jet

How the black hole in M87 launches a jet

April 26, 2023
New observations reveal the powerful jet emerging from the black hole in the centre of the galaxy M87 more
With the help of ALMA, astronomers have obtained a new image of the supermassive black hole at the centre of the M87 galaxy. Credits: ESO Directed by: Angelos Tsaousis and Martin Wallner. Editing: Angelos Tsaousis. Web and technical support: Gurvan Bazin and Raquel Yumi Shida. Written by: Jonas Enander. Music: Stellardrone — Eternity. Footage and photos: ESO/L. Calçada, M. Kornmesser, Digitized Sky Survey 2, ESA/Hubble, RadioAstron, De Gasperin et al., Kim et al., S. Dagnello (NRAO/AUI/NSF), R. S. Lu (SHAO), E. Ros and H. Rottmann/MPIfR, Nicolle R. Fuller/NSF, A. Duro. Scientific consultants: Paola Amico and Mariya Lyubenova.
You can find this video on YouTube. Click on the image to be redirected there.

First image of a black hole expelling a powerful jet 

With the help of ALMA, astronomers have obtained a new image of the supermassive black hole at the centre of the M87 galaxy. Credits: ESO Directed by: Angelos Tsaousis and Martin Wallner. Editing: Angelos Tsaousis. Web and technical support: Gurvan Bazin and Raquel Yumi Shida. Written by: Jonas Enander. Music: Stellardrone — Eternity. Footage and photos: ESO/L. Calçada, M. Kornmesser, Digitized Sky Survey 2, ESA/Hubble, RadioAstron, De Gasperin et al., Kim et al., S. Dagnello (NRAO/AUI/NSF), R. S. Lu (SHAO), E. Ros and H. Rottmann/MPIfR, Nicolle R. Fuller/NSF, A. Duro. Scientific consultants: Paola Amico and Mariya Lyubenova.
https://www.youtube.com/watch?v=4prdUmf5EsA

Selected press coverage

Articles derived from the Nature paper and the related press releases

A Fresh View of an Increasingly Familiar Black Hole (Dennis Overbye), The New York Times, 26 April 2023

Radio astronomers have captured a wide-angle image of one of the most violent locales in the cosmos.

Black-hole image reveals details of turmoil around the abyss (Davide Castelvecchi), Nature, 26 April 2023

Observations of galaxy M87 show how the black hole at its centre relates to a long-seen stream of superheated matter.

Testing Gravity with Black Holes: Can we tell them apart?

16 March 2023

A team of researchers led by the PhD candidate Jan Röder at the MPIfR has used computer simulations to test their ability to distinguish between two theories of gravity under different accretion and emission scenarios. They carried out 3D simulations of two black holes, one based on the Kerr solution to general relativity and the other on ton a branch of solutions to Einstein-Maxwell-dilaton-axion gravity, the dilaton black hole. Further, they modelled thermal synchrotron emission and applied a non-thermal electron distribution function to compare with multi-wavelength observations. The study found that differences between the two black hole spacetimes are not always distinguishable with current observational technology, and that the choice of emission model has a greater effect on the spectra than the accretion model or the choice of spacetime.  More information is available directly at the publication in the last issue of Astronomy and Astrophysics, here.

Radio dynamics of the binary black hole candidate OJ 287 from Effelsberg monitoring

23 February 2023

In a new study from the MOMO program, addressing the multifrequency radio variability of the blazar OJ 287 from 2015 to 2022, led by Stefanie Komossa from the MPIfR, data covering a wide range of activity states and employs data spanning from 2015 to 2022, complemented by Fermi γ-ray observations, are presented.  The team of researchers employ techniques such as discrete correlation functions to analyse the data. The connection between the radio emissions and the multiwavelength radiation is explored in great detail. Fascinatingly, they discover deep fades in both radio and optical-UV fluxes that recur every 1-2 years.  However, one of the most intriguing findings is the absence of a precursor flare of thermal bremsstrahlung, as predicted by one of the binary supermassive black hole models for OJ 287. This raises questions about the prevailing understanding of this blazar's behavior.  The study also focuses on the remarkable 2016/2017 nonthermal outburst initially detected with Swift, shedding light on its nature. The authors propose that this outburst represents the latest occurrence of the famous optical double-peaked outbursts of OJ 287, favoring binary scenarios that do not require a highly precessing secondary supermassive black hole. For more details on this research, check out the full publication in the Astrophysical Journal here.

Peering into the heart of a distant quasar with the Event Horizon Telescope

Peering into the heart of a distant quasar with the Event Horizon Telescope

13 February 2023

A global collaboration of scientists including  Maciek Wielgus of the Max Planck Institute for Radio Astronomy (Bonn, Germany) used the Event Horizon Telescope (EHT), to investigate the innermost parts of the quasar NRAO 530.  Astronomers are trying to understand the complicated physics of quasars and their central engines, struggling with questions like how the jets emanating from the central region are powered and created, and what is the role of magnetic fields in their formation. The EHT offers extremely high, unprecedented angular resolution, allowing astronomers to image the previously unseen structures in the very central region of NRAO 530 (Original Paper: S. Jorstad, M. Wielgus, et al.: "The Event Horizon Telescope Image of the Quasar NRAO 530", in Astrophysical Journal ApJ 943 170 (2023); EHT Blog Entry, February 08, 2023). more

General relativity and the twinkling of Sgr A* in Infrared and X-Ray light

18 January 2023

An international team of astronomers led by Sebastiano von Fellenberg at the MPI für Radioastronomie has studied the supermassive black hole at the center of the Milky Way, called Sagittarius A*.  Astronomers have observed occasional bright flares of near-infrared and X-ray light. These flares are thought to come from the black hole's innermost accretion flow. By analyzing data from the Spitzer and Chandra observatories, the researchers identified 25 near-infrared and 24 X-ray flares. Using a computer program that takes into account the effects of general relativity, the researchers modeled the trajectories of "hot spots" and examined the light curves of the flares for signs of these effects. They found that, despite their varying shapes, all flares share a common, exponential impulse response. This impulse response is symmetric, meaning that the rise and fall times are the same, and has an exponential time constant of about 15 minutes. The researchers determined that the characteristic flare shape is not consistent with hot-spot orbits viewed edge-on, and were able to estimate the inclination of the orbital plane of the hot spots with respect to the observer (about 30 degrees, but less than 75 degrees) and the characteristic timescale of the intrinsic variability (a few tens of minutes).
More information, at the original publication in the Astronomy & Astrophysics journal, here.

Journey to the Heart of a Cosmic Beast: Uncovering the Connection Between Radio Waves and Gamma Rays in 3C 84

03 January 2023

A team of radio astronomers, led by the young scientist Georgios F. Paraschos at the MPI für Radioastronomie, has studied the conection between the high-energy and the radio emission in the nearby quasar 3C 84. The team compared the radio and gamma-ray light curves of 3C 84 (aka NGC 1275) to understand how its jets are formed. By analyzing the time differences between the flares seen in these light curves, they found that the energy of the particles and magnetic fields in the jets are balanced. They also determined the location of the "jet apex" and found that the gamma-ray emission is related to the radio emission. Additionally, the team led by Dr. Paraschos calculated two parameters that describe the properties of the jet, and the results are consistent with a mechanism proposed in 1977 by Blandford and Znajek for jet formation. These findings provide new insights into the mysterious and complex processes that drive the formation and evolution of cosmic jets.
More information at the original publication in the Astronomy & Astrophysics journal, here. 

Astrophysicists find neutrino emission from our Galaxy

Astrophysicists find neutrino emission from our Galaxy

November 29, 2022

Astrophysicists have analyzed publicly available data from the IceCube neutrino observatory in Antarctica. It turned out that a significant component of high-energy neutrino flux is of galactic origin, that is, it was born in the Milky Way. One of the authors, Yuri Kovalev from MPIfR (Bonn, Germany) is excited: "This opens a wonderful opportunity for studying matter in the Galaxy and galactic relativistic objects utilizing methods of multi-messenger astronomy."
These results have been published in the present issue of The Astrophysical Journal (Vol. 940, L41). more
To the Heart of 3C 273

To the Heart of 3C 273

November 22, 2022
International Team Observes Innermost Structure of a Quasar Jet more

A novel multiscale imaging approach for radio interferometry: DoG-HiT

19 October 2022

A new algorithm for imaging interferometric data has been developed by MPIfR astronomers Hendrik Müller and Andrei P. Lobanov, based on a multiscale wavelet deconvolution algorithm, DoG-HiT, for imaging sparsely sampled interferometric data.  The method combines the difference of Gaussian (DoG) wavelets and hard image thresholding (HiT).  DoG-HiT is a stable method and benchmark its performance against image reconstructions made with the CLEAN and regularized maximum-likelihood (RML) methods using synthetic data. The comparison shows that DoG-HiT matches the super-resolution achieved by the RML reconstructions and surpasses the sensitivity to extended emission reached by CLEAN.  Further details of this algorithm can be found the publication presented in the latest issue of Astronomy & Astrophysics, available here. 

A comprehensive summary of the VLBI analysis software, presented to the community

10 October 2022

Very-long-baseline interferometry (VLBI) is a challenging observational technique, which requires in-depth knowledge about radio telescope instrumentation, interferometry, and the handling of noisy data. The reduction in raw data is mostly left to the scientists and demands the use of complex algorithms implemented in comprehensive software packages. The correct application of these algorithms necessitates a good understanding of the underlying techniques and physics that are at play. The verification of the processed data produced by the algorithms demands a thorough understanding of the underlying interferometric VLBI measurements. A review led by MPIfR scientist Michael Janßen, also contributed by Jan Wagner from our institute describes the latest techniques and algorithms that scientists should know about when analyzing VLBI data.  This work is published in the present issue of the scientific journal Galaxies, see here.
 

A ‘Hot Spot’ orbiting Sagittarius A*

A ‘Hot Spot’ orbiting Sagittarius A*

September 22, 2022
Astronomers detect hot gas bubble swirling around the Milky Way’s supermassive black hole more

Unlocking the secrets of 3C 84's powerful jet

31 August 2022

An international team of scientists led by Georgios F. Paraschos from the MPI für Radioastronomie has studied the radio galaxy 3C 84 for over two decades to understand its powerful jets. By using advanced telescopes, researchers were able to produce high-resolution images of the jet's inner core region and determine the kinematics of its ejected features. They found that the jet features travel at speeds between 0.055 and 0.22 times the speed of light and their ejection times coincide with changes in radio and gamma-ray emissions. The scientists also discovered that the jet's width varies with frequency, which suggests that it has a stratified structure. The findings provide insights into the jet's origin and how it evolves over time.
More information, at the publication in the present issue of the Astronomy & Astrophysics journal, here.

How is giant radio galaxy NGC 315's accretion disk powering Its jet?

26 August 2022

A team of astronomers led by Luca Ricci from the MPI für Radioastronomie has studied the properties of a giant radio galaxy, NGC 315, to better understand how the jets seen in active galactic nuclei are powered. Astronomers looked at data from different time periods and frequencies to analyze the source maps and used theoretical models to link the properties of the jet to the physical state of the accretion disk. We found that the bulk flow in NGC 315 accelerates on sub-parsec scales, and this fast acceleration can be explained by magnetism. They also observed a region with a very steep spectral behavior, which indicates that the black hole of NGC 315 is rotating fast and the magnetic flux threading the accretion disk is in excellent agreement with that expected in the case of a magnetically arrested disk (MAD). Using a new technique, they modeled the magnetic field downstream of a quasi-parabolic accelerating jet and reconstructed it up to the event horizon radius. In the MAD scenario, we compared it with the expected magnetic saturation strengths in the disk, finding a good agreement.
More information, at the present issue of the Astronomy & Astrophysics journal, here.

A closer look at the young stars at the galactic center

May 12, 2022

A work led by the MPIfR scientist Maciek Wielgus shows how umerical simulations of accretion discs around a stellar-mass black hole reveal their stratified, elevated vertical structure.These are referred as puffy discs. The work discusses the observational properties of puffy discs, particularly the geometrical obscuration of the inner disc by the elevated puffy region at higher observing inclinations, and collimation of the radiation along the accretion disc spin axis, which may explain the apparent super-Eddington luminosity of some X-ray objects. Synthetic spectra are presented, showing that they are qualitatively similar to those of a Comptonized thin disc.  The work suggests that puffy discs may correspond to X-ray binary systems of luminosities above one third of the Eddington luminosity in the intermediate spectral states.  The results are published in the present issues of the journal Monthly Notices of the Royal Astronomiccal Society, for more information see here.

Astronomers reveal first image of the black hole at the heart of the Milky Way

Astronomers reveal first image of the black hole at the heart of the Milky Way

May 12, 2022
Breakthrough discovery: EHT´s unprecedented observations improve our understanding of what happens at the very centre of our galaxy more
Special episode of RadioViews!<br /><br />This time we have insight information, emotional thoughts, and exciting scientific news collected by the Event Horizon Telescope (EHT) Collaboration members at the Max Planck Institute for Radio Astronomy in Bonn, Germany. It has been a great, devoting journey since Sagittarius A* was observed by the EHT in 2017. Our colleagues tell their side of the story.<br /><br />Created by Joana A. Kramer &amp; Luca Ricci, MPI für Radiastronomie
You can find this video on YouTube. Click on the image to be redirected there.
© RadioViews, J. Kramer, L. Ricci, MPI für Radioastronomie, 2022

EHT Image of the Black Hole in SgrA* - MPIfR scientists tell the story

Special episode of RadioViews!

This time we have insight information, emotional thoughts, and exciting scientific news collected by the Event Horizon Telescope (EHT) Collaboration members at the Max Planck Institute for Radio Astronomy in Bonn, Germany. It has been a great, devoting journey since Sagittarius A* was observed by the EHT in 2017. Our colleagues tell their side of the story.

Created by Joana A. Kramer & Luca Ricci, MPI für Radiastronomie
https://www.youtube.com/watch?v=z1VxC0J6rzA

Astronomers reveal first image of the black hole at the heart of our galaxy - Event Horizon Telescope Official Press Release

Astronomers have unveiled the first image of the supermassive black hole at the centre of our own Milky Way galaxy. This result provides overwhelming evidence that the object is indeed a black hole and yields valuable clues about the workings of such giants, which are thought to reside at the centre of most galaxies. The image was produced by a global research team called the Event Horizon Telescope (EHT) Collaboration, using observations from a worldwide network of radio telescopes.

Astronomers reveal first image of the black hole at the heart of our galaxy - European Southern Observatory Official Press Release


Today, at simultaneous press conferences around the world, including at the European Southern Observatory (ESO) headquarters in Germany, astronomers have unveiled the first image of the supermassive black hole at the centre of our own Milky Way galaxy. This result provides overwhelming evidence that the object is indeed a black hole and yields valuable clues about the workings of such giants, which are thought to reside at the centre of most galaxies. The image was produced by a global research team called the Event Horizon Telescope (EHT) Collaboration, using observations from a worldwide network of radio telescopes.
On 12 May at 15:00 CEST, the European Southern Observatory (ESO) and the Event Horizon Telescope (EHT) project held a press conference to present groundbreaking Milky Way results from the EHT.<br /><br />The ESO Director General delivered the opening words. EHT Project Director Huib Jan van Langevelde and EHT Collaboration Board Founding Chair Anton Zensus delivered remarks. A panel of EHT researchers including Thomas P. Krichbaum (MPIfR) and Christian Fromm (Univ. Würzburg, also affiliated with the MPIfR) explained the result and answer questions from journalists.<br /><br />Following the press conference, at 16:30 CEST ESO hosted an online event for the public via this same streaming link: a live question and answer session where members of the public will have the opportunity to query another panel of EHT experts (which include also Michael Janssen from the MPIfR).
You can find this video on YouTube. Click on the image to be redirected there.

Press Conference at ESO on new Milky Way results from the EHT team, followed by a public Q&A event
 

On 12 May at 15:00 CEST, the European Southern Observatory (ESO) and the Event Horizon Telescope (EHT) project held a press conference to present groundbreaking Milky Way results from the EHT.

The ESO Director General delivered the opening words. EHT Project Director Huib Jan van Langevelde and EHT Collaboration Board Founding Chair Anton Zensus delivered remarks. A panel of EHT researchers including Thomas P. Krichbaum (MPIfR) and Christian Fromm (Univ. Würzburg, also affiliated with the MPIfR) explained the result and answer questions from journalists.

Following the press conference, at 16:30 CEST ESO hosted an online event for the public via this same streaming link: a live question and answer session where members of the public will have the opportunity to query another panel of EHT experts (which include also Michael Janssen from the MPIfR).
https://www.youtube.com/watch?v=rIQLA6lo6R0

Selected press coverage

For the German-speaking reporting, go to our area in German language. 

The Milky Way’s Black Hole Comes to Light, The New York Times (Dennis Overbye), 12 May 2022

The Event Horizon Telescope has once again caught sight of the “unseeable.”

The history of Sagittarius A*, the Milky Way's supermassive black hole, Astronomy.com, Paul Sutter, 12 May 2022

Lifting the dusty veil of the Milky Way's core has taken nearly a century.
 

See The Jaw-Dropping First Image Of The Black Hole At The Heart Of Our Galaxy Just Revealed By Astronomers, Forbes (Jamie Carter), 12 May 2022

The first ever image of the supermassive black hole at the center of our galaxy has been published by the Event Horizon Telescope (EHT). It comes from the same team of over 300 international scientists who produced the first ever image of a black hole in another galaxy in 2019.

Svelata la prima immagine del buco nero al centro della Via Lattea, La Repubblica (Matteo Marini), 12 May 2022

Sagittarius A* si trova al centro della nostra galassia, l’oggetto supermassiccio più vicino a noi. Il team internazionale dell’Eht ha mostrato il frutto di cinque anni di lavoro: “È un’ulteriore conferma della Relatività di Einstein”

Captan la primera imagen del agujero negro de nuestra galaxia, Sagitario A*, probando su existencia, El Mundo (Ángel Díaz & Teresa Guerrero), 12 May 2022

Sagitario A, el agujero negro supermasivo de la Vía Láctea, tiene una masa estimada de unos cuatro millones de soles, y se encuentra a 26.000 años luz

Primera imagen de Sagitario A*, el agujero negro del centro de la Vía Láctea, La Vanguardia (Josep Corbella), 12 May 2022

Las observaciones del astro central de nuestra galaxia confirman las predicciones de Albert Einstein

What you need to know about the Sagittarius A* black hole photo, BBC (Sara Rigby), 16 May 2022

The Event Horizon Telescope is back with another stunning image of a supermassive black hole, this time of the one within our very own Galaxy.

First-ever image of the black hole ‘shadow’ at the heart of the Milky Way revealed by the Event Horizon Telescope, Physics Workd, 12 May 2022

Astronomers working on the Event Horizon Telescope (EHT) have captured the first image of the “shadow” – and glowing surroundings – of the supermassive black hole at the centre of the Milky Way. The achievement is another huge success for the EHT project, which in 2019 released a similar image of the black hole in the core of the galaxy Messier-87.

How high-energy particles shape the appearance of M87: a new study

20 April 2022

An international team of astronomers led by Christian M. Fromm, affiliated to the MPI für Radioastronomie, as well as to the Universities of Würzburg and Frankfurt, presents a new study in the present issue of Astronomy & Astrophysics.  Based on the previous work from the Event Horizon Telescope, which captured images of the innermost emission of the M87 galaxy, revealing a ring-like structure surrounding a supermassive black hole. However, at lower frequencies, the galaxy had a large-scale jet emitting non-thermal energy. To better understand these observations, the team led by Dr. Fromm used simulations to model the accretion of magnetized plasma onto black holes and jet launching. They were able to model the observed broad-band spectrum of M87 and fit the structure of the jet using simulations that included a mixture of thermal and non-thermal particle distributions. These results provide new insights into the behavior of black holes and the surrounding material.
More information is available at the original publication here.

 

The collimation in the twin jet of NGC 1052

09 February 2022

The radio galaxy NGC 1052 has been explored in the innermost regions of its dual jet by means of radio interferometr.  An international team of radio astronomers led by Dr. Anne-Kathrin Baczko from our institut shows  that the jet presents a clear transition in the collimation profile at 10 000 gravitational radii, with an upstream parabolic shape, which turns into conical downstream.  At about 1 000 gravitational radii, the jet has an opening angle of about 30°.  These results show that the approaching (eastern) and receding (western) show a somewhat different emission, for which the receding jet emission my be affected by an absorption cloud of gas in the line of sight.  More information is available at the original publication in the journal Astronomy & Astrophysics, available here. 

Blazar 0716+714 flaring from the radio through the gamma-ray sky

26 January 2022

An international team of astronomers led by DaeWon Kim from the MPI für Radioastronomie have studied blazar 0716+714, more specifically its jet.  They used radio waves and gamma rays to create a picture of how the jet behaves. Over a period of ten years, they found that there were times when the radio and gamma rays were closely linked, and other times when they were not.  They discovered that the gamma rays were being produced by multiple regions in the jet, upstream from where the radio waves were being produced. They were also able to identify different parts of the jet moving at different speeds, and they found that the brightness of the jet decreased as it got further from the center.   Interestingly, the researchers noticed that the times when the radio and gamma rays were closely linked coincided with times when the jet was pointing in a specific direction. They suggest that a moving disturbance, like a shockwave, passing through the radio core and the direction of the jet could be causing the correlation between the radio and gamma rays.  Overall, this study helps us understand how these distant objects behave and provides insight into the complex processes that create the emissions we observe.
More details on the work are presented in the present issue of The Astrophysical Journal, here.

Images at the Highest Angular Resolution in Astronomy

Images at the Highest Angular Resolution in Astronomy

January 19, 2022
How a Binary Black Hole may be Bending the Relativistic Jet in the Quasar OJ 287 more

The 10 biggest space science stories of 2021 (space.com)

January 07, 2022
List of 10 remarkable results in Astronomy & Space Science, including “Event Horizon Telescope takes high-resolution image of black hole jet”, the EHT observations of the very center of galaxy Centaurus A, see also MPIfR press release from July 19, 2021 (Article by Doris Elin Urrutia in space.com, January 01, 2022).
  more

Finalists for the 2021 Breakthrough of the Year (Physics World)

January 07, 2022
Shortlist of 10 breakthroughs within different areas of physics, including “Observing a black hole’s magnetic field”, the EHT results for the magnetic field in the center of M87, see also MPIfR press release from March 24, 2021 (Article by Hamish Johnston in “Physics World”, December 07, 2021).
  more

Best Scientific Discoveries and Breakthroughs of 2021 (Newsweek)

January 07, 2022
Compilation of five scientific breakthroughs within the following areas: Physics, Space,  Chemistry, Biology & Medicine, “Weird Science”. The breakthrough in Physics (“Imaging The Magnetic Field Around A Supermassive Black Hole”) shows the EHT results for the magnetic field in the center of M87, see also MPIfR press release from March 24, 2021 (Article by Robert Lea in “Newsweek”, December 31, 2021). more

Computing polarised jet emission

15 December 2021

A publication presented by Joana A. Kramer, PhD candidate at the MPIfR together with her supervisor, Nicholas R. Macdonald, shows that jet emission is edge-brightened when the magnetic field is toroidal in nature and spine-brightened when the magnetic field is poloidal in nature.  Additionally, the circularly polarized emission exhibits both negative and positive sign for the toroidal magnetic field morphology. Last but not least, the relativistic jet's emission is largely independent of different emission scaling relations when the ambient medium is excluded.  This is based in numerical simulations performed in 3D including relativistic,  magnetohydrodynamic effects (PLUTO code), and synthetic images created from these virtual jets (using the RADMC-3D code, which can reproduce the polarised emission of light coming from its energetic, black-hole-powered plasma.  More details are available in the present issue of Astronomy & Astrophysics, at this publication.

Centaurus A, at the cover of the October 2021 issue of Nature Astronomy.  The work, led by MPIfR researcher Michael Janßen, provides unprecedented detail from the innermost regions of the nearby, prominent Southern galaxy.
Into the Dark Heart of Centaurus A

Into the Dark Heart of Centaurus A

July 19, 2021
Event Horizon Telescope exposes the center of the nearest radio galaxy more

Press release by the Max Planck Society headquarters: Zoom into the dark heart of Centaurus A

The Event Horizon Telescope takes a close-up of the nearest radio galaxy

EHT Pinpoints Dark Heart of the Nearest Radio Galaxy, Event Horizon Telescope

EHT Collaboration Press Release on 19 July 2021

Press echo

English

A deep look at a nearby galaxy's black hole reveals the launching point of intergalactic jets, Phil Plait, Bad Astronomy blog at SyFy Wire, 19 July 2021

The amazing Event Horizon Telescope has done it again: It has taken extraordinarily high-resolution images of the nearby galaxy Centaurus A, revealing twin beams of material shooting away from the supermassive black hole in its heart at a significant fraction of the speed of light.

Event Horizon Telescope captures ‘beautiful’ images of second black hole’s jet, Daniel Clery, Science Magazine, 19 July 2021, quoting Michael Janssen

The astronomy team that 2 years ago captured the first close-up of a giant black hole, lurking at the center of the galaxy Messier 87 (M87), has now zoomed in on a second, somewhat smaller giant in the nearby active galaxy Centaurus A. The Event Horizon Telescope’s (EHT’s) latest image should help resolve questions about how such galactic centers funnel huge amounts of matter into powerful beams and fire them thousands of light-years into space. Together the images also support theorists’ belief that all black holes operate the same way, despite huge variations in their masses.

Event Horizon Telescope Reveals Curious Jet Structure from Black Hole, Camille M. Carlisle, Sky & Telescope, 20 July 2021, quoting Michael Janssen

Observations of the nearest radio galaxy, Centaurus A, provide the highest-resolution look at the long jets shooting from the galaxy’s supermassive black hole.

After capturing first photo of a black hole, Event Horizon Telescope zooms in on a second (Jackson Ryan), c|net, 20 July 2021, quoting Michael Janssen

From the telescope that brought you hits like The First Black Hole Photo comes the best look yet at extreme cosmic jets.

German:

Der Jet aus dem Herzen des Monsters, Franziska Konitzer, Spektrum, 19 July 2021

Dem Event-Horizon-Teleskopverbund gelingt die Aufnahme eines energiereichen Strahls aus einer entfernten Galaxie. Reicht es bald für das Schwarze Loch in ihrem Zentrum?

Schwarze Löcher verhalten sich ähnlich, Rainer Kayser, Welt der Physik, 19 July 2021, quoting Michael Janssen

In den Zentren der meisten Galaxien befindet sich ein Schwarzes Loch mit der millionen- oder gar milliardenfachen Masse unserer Sonne. Einen Blick in die unmittelbare Nähe dieser supermassereichen Objekte zu werfen, war lange nicht möglich. Erst mit dem Event Horizon Telescope, einem Zusammenschluss von Radioteleskopen in aller Welt, gelang die erste Aufnahme eines supermassereichen Schwarzen Lochs. Nun richteten Astronomen den Fokus auf das Zentrum der 13 Millionen Lichtjahre entfernten Radiogalaxie Centaurus A. Die Beobachtungen legen nahe, berichtet das Team jetzt im Fachblatt „Nature Astronomy“, dass sich Schwarze Löcher über einen weiten Massenbereich ähnlich verhalten.

Gewaltiger Jet aus Schwarzem Loch so detailreich wie noch nie, Future Zone, 19 July 2021, quoting Michael Janssen

Mit dem Event-Horizon-Teleskop konnte beobachtet werden, wie ein gigantischer Strahl in einem Schwarzem Loch geboren wird.

Spanish:

El corazón de la galaxia Centaurus A observado con un detalle sin precedentes, Agencia Efe, 19 July 2021

La galaxia Centaurus A ha sido estudiada con un detalle sin precedentes por el Telescopio Horizonte de Sucesos (EHT), lo que ha permitido ubicar el agujero negro supermasivo que hay en su centro y detectar que de él está surgiendo un chorro gigantesco.

Un estudio que publica hoy Nature Astronomy y firmado por un equipo internacional, destaca que lo más sorprendente de las observaciones es que los bordes exteriores de chorro parecen emitir radiación, lo que desafía los modelos teóricos sobre este tipo de fenómenos.

<span>This video Q&amp;A discusses the findings in the upcoming Nature Astronomy paper, 'Event Horizon Telescope observations of the jet launching and collimation in Centaurus A,</span>
You can find this video on YouTube. Click on the image to be redirected there.
© NPG Press

EHT imaging of Centaurus A: A conversation with Nature Astronomy and Michael Janssen (and also the MPIfR alumni Sera Markoff and Marios Karouzos)

This video Q&A discusses the findings in the upcoming Nature Astronomy paper, 'Event Horizon Telescope observations of the jet launching and collimation in Centaurus A,
https://www.youtube.com/watch?v=gbMyZEBmQsY
Jets Pose Many Riddles

Jets Pose Many Riddles

14 July 2021

The super-energetic jets that shoot out of black holes are in the focus of a new DFG research group. The researchers are being funded with 3.6 million euros.  The MPIfR is involved in two sub-projects: Bia Boccardi and J. Anton Zensus lead the sub-project mm-VLBI studies of gamma-ray bright radio galaxies”, and J. Anton Zensus and Eduardo Ros participate at the sub-project led by Matthias Kadler and Christian M. Fromm in Würzburg, with title Jet physics one event horizon scales and beyond. more

The cosmic battery powers galaxy halo magnetic fields

20 May 2021

A publication by the MPIfR-affiliated astronomer Ioannis Myserlis and his colleague Ioannis Contopoulos (Athens) reveals, appeared today at the Astronomy & Astrophysics journal, postulates a universal mechanism to explain the magnetic fields in galactic halos.  The author have studied thirty-five nearby edge-on spiral galaxies from the Extended Very Long Array Survey named Continuum HAlos in Nearby Galaxies – an EVLA Survey (CHANG-ES), and detected large-scale magnetic fields in sixteen of them. The authors used radio polarization data to create Faraday rotation measure maps for all galaxies in the sample and stack them with the aim of amplifying any underlying universal toroidal magnetic field pattern in the halo above and below the disk of the galaxy.  The presented work discovered a large-scale magnetic field in the central region of the stacked galaxy profile, which is attributable to an axial electric current that universally outflows from the center, both above and below the plane of the disk. A similar symmetry-breaking has also been observed in astrophysical jets, but never before in galaxy halos. This is an indication that galaxy halo magnetic fields are probably not generated by pure magnetohydrodynamic processes in the central regions of galaxies. One such promising physical mechanism is the Cosmic Battery operating in the innermost accretion disk around the central supermassive black hole. More details of this work can be found in the original publication here.

Einstein's Theory Can Explain the Black Hole M87*

Event horizon sizes for different theories of gravity. All of these black holes cast dark shadows that are distinguishable from each other in size, but only those that fall in the gray band are compatible with the 2017 EHT measurements of M87*, and in this image, the one represented in red at the bottom is too small to be a viable model for M87*.

20 May 2021

Event Horizon Telescope Collaboration scientists including MPIfR researchers use data which produced the first image of a black hole to constrain its fundamental properties.

In 2019, the EHT Collaboration published the first image of a black hole located at the centre of the galaxy M87. Now a collaboration team led by theoretical physicists at the Goethe University Frankfurt and with the participation of the MPIfR EHT team have analysed data from the black hole M87* to test Albert Einstein's theory of general relativity. According to the tests, the size of the shadow from M87* is in excellent agreement with a black hole predicted by general relativity, but narrows the properties of black holes in other theories down. These results are presented in today’s issue of the Physical Review D journal.

You can find this video on YouTube. Click on the image to be redirected there.
© Goethe University Frankfurt, P. Kocherlakota, L. Rezzolla, Fiks Film, Event Horizon Telescope Collaboration (2021)

Constraining black hole models with EHT observations | Event Horizon Telescope

https://www.youtube.com/watch?v=Xf8He6Z1eQU

Einstein's Theory Can Explain the Black Hole M87*

EHT Collaboration Press Release on May 20, 2021

X-ray studies from the binary black hole candidate OJ 287

05 May 2021

A new study of the quasar OJ 287, led by the MPI für Radioastronomie scientist Stefanie Komossa, presents results from spectroscopic observations performed between 2005 and 2020.  In the long period of study, the galaxy nucleus presents extreme activity minima and outbursts.  The X-ray spectrum of the source can be decomposed into three components: low-state emission consisting by Inverse Compton photons, super-soft synchrotron emission becoming dominant as the source brightens, and an additional outburst component with intermediately-soft photons.  The publication discuss in detail the postulated black hole binary nature (having the primary black hole a mass of 18 billion solar masses) of the central region and the X-ray results.  More details can be found at the original publication, presented at the latest issue of Monthly Notices of the Royal Astronomical Society.

Black holes as magnetic jet engines

Black holes as magnetic jet engines

April 22, 2021
European Research Council supports Bonn astrophysicists with 2.5 million euros to explain the phenomenon more

Challenging the radio galaxy classification with the VLA-COSMOS survey at 10 cm wavelength

20 April 2021

An international team of astronomers led by Eleni Vardoulaki (affiliated to the MPI für Radioastronomie, at present at the Thüringer Landessternwarte in Tautenburg) has studied a sample of faint radio galaxies down to μJy levels with the 15-GHz sample of the VLA-COSMOS survey.  Radio active galactic nuclei (AGN) are traditionally separated into two Fanaroff-Riley (FR) type classes, edge-brightened FRII sources or edge-darkened FRI sources. This dichotomy is becoming too simplistic in linking the radio structure to the physical properties of radio AGN, their hosts, and their environment.  The work by Vardoulaki and collaborators approached the study of these galaxies both measured by a machine-learning algorithm and also by hand, following a parametric approach to the FR classification. Different physical parameters were estimated, as well as the galaxy host properties.  The work shows a broad distribution and overlap of Fanaroff-Riley radio galaxies and jet-less/compact radio active galactic nuclei populations.  The results point to the need for a different classification scheme, that expands the classic  classification by taking into consideration the physical properties of the objects rather than their projected radio structure which is frequency-, sensitivity- and resolution-dependent. 

These results are presented in the last issue of the journal Astronomy & Astrophysics, see the original publication here.

RadioAstron reveals the complex structure in the jet of quasar 3C 345

Space (blue contours) and ground-array (heat colour scale) radio interferometric image of the quasar 3C 345 at a wavelength of 21 cm.  The image reveals the big step forward in resolution provided by the RadioAstron mission.  Figure 2 from the original publication (F. Pötzl et al., A&amp;A 648, A82, 2021).

14 April 2021

A team of radio astronomers led by the MPIfR astrophysicist Felix M. Pötzl has studied the innermost jet morphology and magnetic field strength in the active galactic nucleus (AGN) 3C 345 with an unprecedented resolution using images obtained within the framework of the key science programme on AGN polarisation of the Space VLBI mission RadioAstron.  The results analyze images obtained at a wavelength of 21 cm on 2016 March 30 with RadioAstron and eighteen ground-based radio telescopes.  The obtained images reveal a complex jet structure a resolution corresponding to a projected linear scale of about 2 pc or a few thousand gravitational radii.  This work identfies the synchrotron self-absorbed core at the jet base and find a brightest feature in the jet several parsecs downstream of the core.  The work also studies the linearly polarised emission, which is related to the magnetic field distribution in the jet, and the intrinsic brightness of the source and its information about the source physics (via the so-called brightness temperature).

Additional information can be obtained at the original publication here.

Multifrequency Observations of M87*

Multifrequency Observations of M87*

April 14, 2021
Telescopes unite in unprecedented observations of the famous black hole more
<p>Beginning with the EHT’s now iconic image of M87, a new video takes viewers on a journey through the data from each telescope. Each step provides data across many factors of ten in scale, both of wavelengths of light and physical size.</p>
You can find this video on YouTube. Click on the image to be redirected there.
© The EHT Multi-wavelength Science Working Group, the collaborations of the EHT, EAVN, H.E.S.S., MAGIC and VERITAS; EVN; VLBA; GMVA; HST; Swift; Chandra; NuSTAR; Fermi; NASA, ESA and ESO

Zoom Out of the Black Hole M87*

Beginning with the EHT’s now iconic image of M87, a new video takes viewers on a journey through the data from each telescope. Each step provides data across many factors of ten in scale, both of wavelengths of light and physical size.

https://www.youtube.com/watch?v=q2u4eK-ph40
Event Horizon Telescope 2021

Event Horizon Telescope 2021

April 14, 2021
Observing campaign in April 2021: world-wide radio telescope network retakes observations after 3-year long break more
The Opticon-RadioNet Pilot Project (ORP) is launched

The Opticon-RadioNet Pilot Project (ORP) is launched

March 25, 2021
Kick-off for Europe’s largest astronomy network more

A swing in the jet direction at the quasar 3C 273

Sketch of a sheath wrapped around the wide jet in 3C 273.  Subject to the single-epoch relativistic jet orientation, synchrotron emission of the jet passes through different parts of the sheath. Faraday rotation measures values change from positive to negative in 2003.  If the jet turns southwards, only negative rotation measures.

24 March 2021

The high-redshift radio source with number 273 in the third Cambridge catalog (also known as 4C +02.32, ON 044, or CTA 053) is one of the best studied objects in very-long-baseline interferometry.  New results presented in a publication led by the Bonn astronomer Misha Lisakov reveals changes in the polarisation of the jet which suggest a change in the jet direction during the period 2009-2010 from multi-wavelength studies using the Very Long Baseline Array.  The work, presented in the latest issue of The Astrophysical Journal, shows that the jet Faraday rotation measure has changed significantly toward negative values compared with that previously observed. These changes could be explained by a swing of the parsec-scale jet direction, which causes synchrotron emission to pass through different portions of the Faraday screen. The work develops a model for the jet-sheath system in 3C 273 where the sheath is wider than the single-epoch narrow relativistic jet.  The wide jet–sheath boundary is about 750 light years downstream from its beginning. Most of the Faraday rotation occurs within the innermost layers of the sheath.   Further details on the jet parameters and the impact of this work in the study of other sources can be obtained in the original publication, see here.

EHT Astronomers Image Magnetic Fields at the Edge of M 87’s Black Hole

EHT Astronomers Image Magnetic Fields at the Edge of M 87’s Black Hole

March 24, 2021
The EHT has imaged the polarised emission of the ring around the black hole shadow in Messier 87.  The polarimetry working group of the collaboration, mostly responsible of this result, is coordinated by Iván Martí-Vidal (Univ. València, alumnus of the MPIfR) and Monika Mościbrodzka (Radboud Univ.); additionally Jason Dexter (Univ. Colorado Boulder, alumnus of the MPI for extraterrestrial Physics) and Andrew Chael (Princeton) coordinated the theory part of the work. more
You can find this video on YouTube. Click on the image to be redirected there.
© ESO/L. Calçada, Digitized Sky Survey 2, ESA/Hubble, RadioAstron, De Gasperin et al., Kim et al., EHT Collaboration. Music: Niklas Falcke

Zoom into the Magnetized Black Hole M87* | Event Horizon Telescope

https://www.youtube.com/watch?v=ghoUhPbzFiQ
You can find this video on YouTube. Click on the image to be redirected there.
© Ivan Marti-Vidal, University of Valencia, and the EHT Collaboration

The Black Hole M87* Seen Through a Polarizer | Event Horizon Telescope

https://www.youtube.com/watch?v=AU2qGTpMn8I
You can find this video on YouTube. Click on the image to be redirected there.
© Radboud University, Goethe University Frankfurt, EHT Collaboration; produced by Fiks Film

What is Polarization? | Event Horizon Telescope

https://www.youtube.com/watch?v=Un-9fbqlIKo
You can find this video on YouTube. Click on the image to be redirected there.
© Smithsonian Astrophysical Observatory and the EHT Collaboration; produced by CrazyBridge Studios

How Magnetic Fields Affect Black Hole Images | Event Horizon Telescope

https://www.youtube.com/watch?v=6xrJoPjfJGQ

Official EHT Press Release: Astronomers Image Magnetic Fields at the Edge of M87’s Black Hole (quoting, among others MPIfR alumnus Iván Martí-Vidal from the Univ. València)

The Event Horizon Telescope (EHT) collaboration, who produced the first ever image of a black hole, has revealed today a new view of the massive object at the centre of the M87 galaxy: how it looks in polarised light. This is the first time astronomers have been able to measure polarisation, a signature of magnetic fields, this close to the edge of a black hole. The observations are key to explaining how the M87 galaxy, located 55 million light-years away, is able to launch energetic jets from its core.

Media Echo

English

Astronomers detct strong magnetic fields around M87's black hole, Camille M. Carlisle, Sky & Telescope, 24 March 2021

Event Horizon Telescope data support the idea that magnetic fields control how black holes feed and grow.

Mysterious swirling light gives new insights into black holes, Linda Geddes, The Guardian, 24 March 2021

Experts discover crucial evidence that could reveal how magnetic fields behave around black holes.

Scientists reveal first EVER photo of a supermassive black hole in polarised light: M87's galactic centre is caught on camera and could help to explain how the stellar phenomenon 'eats' matter, Ryan Morrison, Daily Mail, 24 March 2021

The supermassive black hole at the centre of the galaxy M87 is more than 6.5 billion times the mass of the sun.  Astronomers used the Event Horizon Telescope to capture the sensational new images of the massive object.  The black hole was the first to be directly imaged by astronomers and this new image is from the same data.  The new image allowed the astornomers to measure polarisation from the light surrounding the black hole.

The Most Intimate Portrait Yet of a Black Hole, Dennis Overbye, The New York Times, 24 March 2021

Two years of analyzing the polarized light from a galaxy’s giant black hole has given scientists a glimpse at how quasars might arise.

Global telescope creates exquisite map of black hole’s swirling magnetic field, Alison Kiesman, Astronomy, 24 March 2021

The Event Horizon Telescope’s newest images of M87’s supermassive black hole hint at how its jets are fired far into space.

See a Black Hole's Magnetic Fields in New Image From the Event Horizon Telescope, Isaac Schultz, Gizmodo, 24 March 2021

Magnetic Field around a Black Hole Mapped for the First Time, Stephanie Pappas, Scientific American, 24 March 2021

Images from the Event Horizon Telescope reveal new details of how supermassive black holes produce huge jets of matter and energy.

New picture of famous black hole reveals its swirling magnetic field, Leah Crane, New Scientist, 24 March 2021

The first picture of a black hole’s shadow just got even more interesting. The Event Horizon Telescope (EHT) collaboration released the first direct image of a black hole in 2019, and while the picture on its own was impressive, it wasn’t the scientific smorgasbord some had hoped for. Now, researchers have added polarised light to the picture, giving us an idea of how magnetic fields around a supermassive black hole create powerful jets of matter.

Event Horizon Telescope sees the Magnetic Engine behind a Supermassive Black Hole's Immense Power, Phil Plait, Bad Astronomy, 24 March 2021

In 2019, astronomers stunned the world, releasing an epic image of material swirling around the supermassive black hole in the core of the galaxy M87 55 million light years from Earth. They connected radio telescopes from around the planet to create the Event Horizon Telescope, a virtual telescope mimicking the power of a telescope the size of our planet, to achieve this amazing observation.

German

Schwarzes Loch: Warum ein Monster im All Materie ausspuckt, Johannes Magnus, Rhein-Zeitung, 31 March 2021, quoting J.A. Zensus

Acht riesige Radioteleskope beobachteten 2017 vier Tage lang gemeinsam ein Monster im All: das Schwarze Loch inmitten der fernen Galaxie M87. 55 Millionen Jahre lang waren die Licht- und Radiowellen von dort bis zur Erde gereist, wo sie eingefangen wurden. Die Daten der Teleskope wurden zwei Jahre lang mit Supercomputern zusammengerechnet und überprüft. Dann präsentierten die Astronomen der Menschheit das erste Bild eines Schwarzen Lochs. Nun haben sie den Daten weitere Einzelheiten entlockt und entdeckten gigantische Magnetfelder um den kosmischen Giganten.

Schwarzes Loch in der Galaxie M87: Forschende machen Magnetfelder sichtbar – „Schlüssel zum Verständnis“, Tanja Banner, Frankfurter Rundschau, 31 March 2021

Das erste schwarze Loch, das von Forschenden fotografiert wurde, sorgt erneut für Aufsehen: Ein Forschungsteam hat nun seine Magnetfelder untersucht.

Forscher machen Magnetfelder nah an Schwarzem Loch sichtbar, Wochenblatt.de, 30 March 2021, quoting J.A. Zensus

Das erste Bild eines schwarzen Lochs, das von Forschenden fotografiert wurde, sorgt bereits 2019 für Aufsehen: Nun haben die Experten seine Magnetfelder unter die Lupe genommen.

Erstmals Magnetfelder am Rand eines Schwarzen Lochs gemessen, Der Standard, 27 March 2021, quoting J.A. Zensus

Vor zwei Jahren konnte erstmals der Schatten eines Schwarzen Lochs fotografiert werden. Jetzt entdeckten Forscher dort polarisierte Radiostrahlung.

Schwarzes Loch in polarisiertem Licht, Welt der Physik, 24 March 2021

Am 10. April 2019 veröffentlichten Wissenschaftler das allererste Bild eines Schwarzen Lochs, das eine helle ringförmige Struktur mit einer dunklen zentralen Region – dem Schatten des Schwarzen Lochs – zeigt. Die zugrunde liegenden Daten, gesammelt mit dem Event Horizon Telescope, hat die Kollaboration seither noch eingehender untersucht. Ein signifikanter Anteil des Lichts um das supermassereiche Objekt im Zentrum der Galaxie M87 ist demnach polarisiert. Und das zeige deutlich, dass der Ring um das Schwarze Loch magnetisiert ist, berichtet das Team nun in zwei separaten Artikeln in der Fachzeitschrift „The Astrophysical Journal Letters“.

Erster Blick auf Magnetfelder am Schwarzen Loch, Nadja Podbregar, Wissenschaft.de, 24 March 2021

Im April 2019 sorgte das erste Foto eines Schwarzen Lochs für weltweites Aufsehen. Jetzt zeigt das Event Horizon Telescope (EHT) weitere Details des supermassereichen Schwarzen Lochs im Zentrum der Galaxie M87. Denn erstmals haben die Astronomen auch die Polarisation des Lichts gemessen, das direkt am Rand des Schwarzen Lochs frei wird. Diese Schwingungsrichtung des Lichts liefert wertvolle Informationen über die Magnetfelder im Umfeld eines solchen Schwerkraftgiganten und könnte erklären, wie es dieser aktive Galaxienkern schafft, extrem energiereiche Strahlen- und Materiejets zu erzeugen.

Aufnahme des Schwarzen Lochs von M87: Polarisiertes Licht verrät Magnetfelder, Martin Holland, heise.de, 24 March 2021

Die erste direkte Aufnahme des Ereignishorizonts eines Schwarzen Lochs enthält noch Überraschungen: Das Licht macht die Magnetfelder vor Ort sichtbar.

Magnetfelder im Vorhof der Hölle, Robert Gast, Spektrum der Wissenschaft, 24 March 2021

2019 blickte die Menschheit direkt in das Schwarze Loch im Herzen der Galaxie M87. Nun haben Forscher neue Details aus der weltberühmten Aufnahme herausgeholt.

Das Schwarze Loch offenbart neue Geheimnisse, Sibylle Anderl, Frankfurter Allgemeine Zeitung, 24 March 2021

2019 war es das eindrucksvollste Wissenschaftsbild: Die erste Aufnahme eines Schwarzen Lochs, aufgenommen mit einem erdumspannenden Teleskopverbund. Nun hat es ein Upgrade erhalten.

Auf der Spur der kosmischen Fackel, Jörg Römer, Der Spiegel, 24 March 2021

Forscher haben das erste Bild eines schwarzen Lochs neu ausgewertet. Dabei kamen sie dem Ursprung von mächtigen Plasmastrahlen so nah wie nie zuvor.

Forscher machen Magnetfelder nah an Schwarzem Loch sichtbar, Süddeutsche Zeitung (dpa), 24 March 2021, quoting J.A. Zensus

Vor rund zwei Jahren veröffentlichten Forscher zum ersten Mal das Bild eines Schwarzen Loches.  Nun sind sie bei der genaueren Untersuchung des Schwerkraftmonsters in der weit entfernten Galaxie Messier 87 (M87) einen weiteren Schritt vorangekommen.

French

Le trou noir géant M87 commence à livrer ses secrets, Le Figaro, 25 March 2021

Le 10 avril 2019, une collaboration d'astronomes internationale avait montré le premier cliché d'un trou noir, au cœur de la galaxie M87.

Voici à quoi ressemble le champ magnétique au bord du trou noir M87*, Nelly Lesage, Numerama, 24 March 2021

La collaboration de l'Event Horizon Telescope a obtenu une nouvelle image importante du trou noir M87*. Elle est réalisée en lumière polarisée, ce qui offre un aperçu unique du champ magnétique aux abords du trou noir.

Spanish

Primera observación del campo magnético circundante a un agujero negro, Ignacio Crespo, La Razón, 25 March 2021

Haber obtenido una imagen del campo magnético de las inmediaciones de un agujero negro podría ayudar a entender los grandes chorros emitidos por este.

Observan por primera vez los campos magnéticos de un agujero negro, Rafael Ordóñez, El Independiente, 24 March 2021

El Telescopio del Horizonte de Sucesos (EHT), que produjo la primera imagen de un agujero negro, ha revelado hoy una nueva vista del objeto masivo en el centro de la galaxia Messier 87 (M87). Se trata de un nuevo hito en la observación astronómica al analizar, en luz polarizada, el agujero negro supermasivo.

Primera imagen del campo magnético que rodea a un agujero negro, Felipe Sasso, Digital Trends, 24 March 2021

Una nueva imagen permite observar por primera vez el 'borde' de un agujero negro, José Manuel Nieves, ABC, 24 March 2021

Es la primera vez que se consigue fotografiar el agujero negro M87 en luz polarizada, lo que permitirá comprender la naturaleza de los enormes chorros de energía que surgen del corazón de la galaxia.

Una nueva imagen de un agujero negro, Ernesto Lozano Tellechea, Investigación y Ciencia, 24 March 2021

La colaboración EHT obtiene las primeras imágenes en luz polarizada de un agujero negro. El hito permite reconstruir el campo magnético en las inmediaciones del objeto y aporta pistas clave para entender cómo se comporta la materia caliente que lo rodea.

Se observan los campos magnéticos en el borde del agujero negro de la galaxia M87, desQbre, 24 March 2021, quoting MPIfR alumnus Iván Martí-Vidal (Univ. València)

La colaboración del Telescopio del Horizonte de Sucesos (EHT por sus siglas en inglés), que produjo la primera imagen de un agujero negro, ha revelado hoy una nueva perspectiva del objeto masivo en el centro de la galaxia M87: cómo se ve en luz polarizada. Se trata de la primera vez que los astrónomos han podido medir polarización, la “firma” de los campos magnéticos, tan cerca del borde de un agujero negro. Las observaciones son clave para explicar cómo la galaxia M87, ubicada a 55 millones de años luz de distancia, puede lanzar chorros de material muy energéticos desde su núcleo.

A ring accelerator to produce neutrinos in a quasar jet?

Illlustration of the different components in the flat-spectrum radio quasar PKS 1502+106.  The jet as a whole is precessing, the interaction of the curved precessing jet with the ionized outflow, in particular the denser clouds, may be responsible for the formation of the ring structure with time.  Taken from Fig. 19 at the original publication.

17 March 2021

An international team of radio astronomers led by Silke Britzen at the MPI für Radioastronomie suggests the connection between the high-energy neutrino production in the quasar PKS 1502+106 with remarkable features in the jet.  Their analysis suggests a radio ring structure in the parsec-scale jet that develops with time. Several arc-structures evolve perpendicular to the jet ridge line. The work also finds hints for precession of a curved jet based on kinematic modelling and a periodicity analysis.  The atypical ring may be connected to an interaction of the precessing jet with the outflowing material.  Energetic neutrinos are most likely produced by proton–proton interaction in the blazar zone, enabled by episodic encounters of the jet with dense clouds, that is, with some molecular cloud in the outer part.  These results have been published today for the May 2021 issue of the British journal Monthly Notices of the Royal Astronomical Society.  For additional information, see here. 

Collimating jets in radio galaxies: the case of NGC 315

The jet in the galaxy NGC 315 from scales of light-weeks (bottom) to light-millions of years (top).

11 March 2021

A study presented by a European team led by the MPIfR astronomer Bia Boccardi (head of an Otto Hahn Research Group) today in Astronomy and Astrophysics reveals a zoom in the structure of the powerful jets in this radio galaxy.  The double jet in this galaxy shows a remarkable persistence in its direction at very different scales.  The collimation, apparently, is already completed in the innermost region (parabolic shape) and is kept for scales much larger than the optical galaxy (conical shape). 

The optical nebula hosting the powerful jet has the number 315 in the New General Catalogue (NGC 315).  It is an elliptical galaxy in the constellation Pisces.  It was discovered on September 11, 1784 by William Herschel.  It is also known as HOLM 028A, OB +392, and TXS 0055+300.

Furthermore, Boccardi's work discusses the possibility that relativistic jets are collimated by winds originated by the accretion disk which surrounds the super massive black hole.  The study suggests that a powerful external layer in the jets (sheath) stabilizes the inner spine by isolating it from the interstellar medium, so that the jet travels mostly unperturbed to reach the intergalactic medium.  These considerations also play a role to define the different types of galaxy, classified as type I (luminosity decreases as the distance from the central galaxy or quasar host increase) or type II (increasing luminosity in the lobes) in 1974.  The publication (open access) can be found here.

Honour for the Event Horizon Telescope (EHT)

Honour for the Event Horizon Telescope (EHT)

January 08, 2021
The 2021 Royal Astronomical Society Group Achievement Award goes to the EHT Project more
The Opticon-RadioNet Pilot Project (ORP)

The Opticon-RadioNet Pilot Project (ORP)

December 22, 2020
European Commission facilitates use of European telescopes more

The monster awakes: galaxy flares after years of silence

28 October 2020

The narrow-line Seyfert 1 galaxy Markarian 335 hosted a very bright X-ray active nucleus which faded since 2007.  Observations from the Swift observatory led by S. Komossa at the MPI für Radioastronomie show a sequence of bright and rapid flare events in the X-ray band, after a long "quiet" time.  The new activity in the source can be explained by a decrease of the amount of matter between the active nucleus and us, which partially covered the bright emission.  The curtain is lifted, and it shows, the "monster" seems to be awake, but was always there.  This work is published in the present issue of Astronomy & Astrophysics, see here.

After the footprints of stellar formation: isotope dating of the clouds to the Galactic Centre

23 October 2020

The present issue of the Astronomy & Astrophysical journal reports about spectral-line observations towards the Galactic centre clouds, in a project led by the PhD researcher Pedro Humire.  This study shows a drop in the production of massive stars at the Galactic centre, based on measurements of the carbon and sulphur abundances in the interstellar medium.  For that different isotopes int he CS molecule were studied (combinations of atomic weight values of 12 and 13 for carbon, and of 32, 33, and 34 for sulphur).  Isotopic ratios can be computed for the different species, and the study shows that the decreasing trend in the 32S/34S ends at about 425 light-years from the centre of our galaxy.  More details can be checked at the original publication, here.

The connection between gamma rays and radio emission in radio galaxies

23 September 2020

A work presented by R. Angioni from the MPI für Radioastronomie gives new clues on the connection between the low-energy (radio) and the high-energy (gamma) emission in radio galaxies.  This is part of a larger work which is presented in a series of publications; the present report focus on prominent radio galaxies in the Southern hemisphere which were not detected by the Fermi/LAT telescope, and gives details on the jet kinematics for several objects.  In general, the study shows that high-energy emission from radio galaxies is related to parsec-scale radio emission from the inner jet, but is not driven by relativistic Doppler boosting effects, in contrast to the situation in blazars.  The results are presented in the last issue of Astronomy & Astrophysics, for more information see here. 

The ring around the M 87* black hole shadow glitters

The ring around the M 87* black hole shadow glitters

September 22, 2020
Turbulent evolution of the M 87* black hole image from 2009 to 2017 more
<p><span class="style-scope yt-formatted-string" dir="auto">This animation presents about three years in the life of M87*, as predicted by numerical simulations. It shows the expected appearance and dynamics of the supermassive black hole as observed by the EHT. You can see turbulent gas heated to billions of degrees swirling around the event horizon, before finally plunging into the black hole. A sharp bright ring surrounding the black hole shadow is an effect of extremely strong lensing near the so-called photon shell</span><span class="style-scope yt-formatted-string" dir="auto">. </span></p> <p><span class="style-scope yt-formatted-string" dir="auto">The blurred portion of the animation corresponds to the effective resolution of the EHT. The dashed black ring measures 42 microarcseconds in diameter. The clock hand indicates the position of the bright side of the fitted crescent. We expect that the bright side should be most of the time located in the bottom of the image, where the velocity of the rotating gas is pointed in the observer’s direction. However, because of the turbulence, the fitted position angle varies quite a bit - the crescent wobbles. By studying the time-variability of the M87* image with the EHT, we can learn about the physics of matter in an extreme environment very near the event horizon, and understand the relations between the black hole and the accretion flow surrounding it. </span></p>
You can find this video on YouTube. Click on the image to be redirected there.
© G. Wong, B. Prather, C. Gammie, J. Farah, M. Wielgus, and the EHT Collaboration

The Wobbling Shadow of the M87* Black Hole

This animation presents about three years in the life of M87*, as predicted by numerical simulations. It shows the expected appearance and dynamics of the supermassive black hole as observed by the EHT. You can see turbulent gas heated to billions of degrees swirling around the event horizon, before finally plunging into the black hole. A sharp bright ring surrounding the black hole shadow is an effect of extremely strong lensing near the so-called photon shell. 

The blurred portion of the animation corresponds to the effective resolution of the EHT. The dashed black ring measures 42 microarcseconds in diameter. The clock hand indicates the position of the bright side of the fitted crescent. We expect that the bright side should be most of the time located in the bottom of the image, where the velocity of the rotating gas is pointed in the observer’s direction. However, because of the turbulence, the fitted position angle varies quite a bit - the crescent wobbles. By studying the time-variability of the M87* image with the EHT, we can learn about the physics of matter in an extreme environment very near the event horizon, and understand the relations between the black hole and the accretion flow surrounding it. 

https://www.youtube.com/watch?v=v_Bk2997YMA

Media echo

English

The first-ever image of a black hole is now a movie, Davide Castelvecchi, Nature, 23 September 2020

Pictures created from old observations show the void’s stormy evolution over the past decade.

EHT data show turbulence makes the glowing ring around M87’s black hole wobble, Maria Temming, Science News, 23 September 2020

Famous for the first-ever image of a black hole, M87* is now revealing how it changes over time

Surprise! The ring around M87 galaxy's monster black hole wobbles over time, Mike Wall, Space.com, 23 September 2020

The Event Horizon Telescope team is learning about the huge black hole's behavior over the past decade.

History-making black hole seen to do a shimmy, Jonathan Amos, BBC, 23 September 2020, quoting Anton Zensus

When scientists presented the first ever picture of a black hole last year, it was hailed as an extraordinary breakthrough.

Well, now they've reassessed some of the image data that was acquired in the years running up to that historic snapshot.  And it gives us some fresh perspectives on the object known as M87*, which has the monster mass of 6.5 billion Suns. One insight is recognising the black hole's brightness flickers over time.

The ring of material around M87's supermassive black hole is changing with time, Phil Plait, Bad Astronomy, SyFy Wire, 23 September 2020

Last year, astronomers revealed a stunning image showing a ring of matter swirling around a supermassive black hole, and a dark hole in the ring representing the black hole’s “shadow.”  That iconic image of the black hole represents a week of observations taken in 2017 by the Event Horizon Telescope (EHT), an array of eight telescopes spread across the world, linked together to increase their resolving power. A team of astronomers tackled this hefty project, and found two important things: The size of the ring and the “shadow” didn’t change, but the brightness of the ring did. Not only that, where it was brightest changed, too, and it’s not clear why.

Black Hole Alight in Glitter, James Maynard, medium.com, 23 September 2020, quoting Anton Zensus

The M 87 black hole, the first body of its type ever photographed by astronomers at the Event Horizon Telescope, shows an unusual glitter…

Astrophysicists Release Landmark “Movie” of Wobbling Black Hole, Victor Tangermann, Futurism, 23 September 2020

"If you want to see a black hole evolve over a decade, there is no substitute for having a decade of data."

This weirdly wobbling black hole upends our theories of the universe, Chris Davies, Slash Gear, 23 September 2020

Black holes are known for being voracious, inescapable, and some of the most impressive elements of the known universe, but what we didn’t realize until now is that they can wobble

The Giant Black Hole We Imaged For The First Time Now Appears to Be… Glittering, Michelle Starr, Science Alert, 25sep2020, quoting Anton Zensus

Last year, for the first time, the world gazed in collective wonder at an actual direct image of a black hole's shadow.  Now, looking back at earlier, more rudimentary images, scientists have found evidence that the ring around M87* has a wobble that makes it look as though it's glittering.

German

Jahrhundertentdeckung M87* - Ring um Schwarzes Riesen-Loch wackelt, Mitteldeutsches Rundfunk, 23 September 2020, quoting Anton Zensus 

Das riesige Schwarze Loch M87*, dessen Bild 2019 eine der großen astronomischen Sensationen war, hält immer neue Überraschungen parat. Nun haben Forscher unter Bonner Federführung herausgefunden, dass sein Ring offenbar hin- und herwackelt.

Himmlisches Flackern, Johanes Grolle, Der Spiegel, 23 September 2020, quoting Thomas Krichbaum and Anton Zensus

Ein kreisrunder Schatten, umschlossen von einem lodernden Ring: Vor anderthalb Jahren sorgte das erste Foto eines schwarzen Loches für Furore. Jetzt legen die Radioastronomen mit neuen Details nach.

Das Schwarze Loch in der Galaxie Messier 87 ist die Ruhe selbst – doch drumherum tut sich was, Neue Züricher Zeitung, Christian Speicher, 23 September 2020, quoting Eduardo Ros

Vor einem Jahr gelang Astronomen zum ersten Mal ein Schnappschuss eines Schwarzen Lochs. Ein Vergleich mit älteren Beobachtungen zeigt nun, wie turbulent es in dessen Umgebung zugeht.

Ring um Schwarzes Loch funkelt, Tagesspiegel, Ralf Nestler, 23 September 2020, quoting Thomas Krichbaum and Anton Zensus and MPIfR alumni Matthias Kadler and Reinhard Genzel

Mit dem Event Horizon Telescope beobachten Forschende Schwarze Löcher. Jetzt interpretieren sie turbulente Vorgänge in der Galaxie Messier 87.

Der funkelnde Ring um das Schwarze Loch in Messier 87, Spektrum der Wissenschaft, Andreas Müller, 23 September 2020, quoting Thomas Krichbaum

Radioastronomen gelangen neue Aufnahmen mit dem Event Horizon Telescope. Die Bilder aus dem Herzen der aktiven Galaxie Messier 87 im Sternbild Virgo zeigen einen funkelnden Ring um das zentrale extrem massereiche Schwarze Loch.

Event Horizon Telescope: Das Schwarze Loch von M87 funkelt, Martin Holland, heise, 23 September 2020, quoting Thomas Krichbaum

Das Schwarze Loch im Zentrum der Galaxie M87 wurde als erstes direkt abgebildet. Nun haben Forscher aus Archivdaten ermittelt, wie sich das Abbild verändert.

Schwarzes Loch: Ereignishorizont „wackelt“, Nadja Podbregar, ScineXX, 24 September 2020, quoting Anton Zensus

Event Horizon Teleskop zeigt zeitliche Veränderungen am Schwarzen Loch M87*

Schwarze Löcher: Forscher entdecken funkelnden Ring, Constantin Krüger, 24sep2020, quoting Thomas Krichbaum

Über schwarze Löcher wissen wir nur sehr wenig. Doch nun haben Forscher entdeckt, dass der Ring um das wohl berühmteste schwarze Loch in Messier 87 funkelt.

Ein Koloss im Wandel, Sibylle Anderl, Frankfurter Allgemeine Zeitung, 01 October 2020

Das erste Bild vom Schatten des Schwarzen Lochs im Zentrum der Galaxie M 87 war 2019 eine wissenschaftliche Sensation. Jetzt haben sich die Astronomen des Event Horizon Telescope ältere Beobachtungsdaten angesehen. Sie konnten verfolgen, wie sich der helle Ring des Massenmonsters über mehrere Jahre hinweg verändert hat und zu funkeln scheint.

Russian

Астрономы увидели мерцающую тень черной дыры, РИА Новости, 23 September 2020, quoting Thomas Krichbaum and Anton Zensus

Ученые подняли архивные данные астрономических наблюдений и выяснили, что тень черной дыры М87* меняется со временем — она мерцает и переливается. Результаты исследования опубликованы в журнале Astrophysical Journal.

Телескоп горизонта событий увидел колебания яркости тени черной дыры, N+1, 23 September 2020

Коллаборация Телескопа горизонта событий (EHT) опубликовала результаты анализа данных наблюдений за сверхмассивной черной дырой в галактике М87 в течение восьми лет. Ученым удалось подтвердить стабильность диаметра тени, а также увидеть изменения ее яркости, что согласуется с теоретическим предсказаниями. Статья опубликована в журнале The Astrophysical Journal.

Spanish

El primer agujero negro capturado en imagen sufre una evolución turbulenta, El Universal, 23 September 2020

El centro de la galaxia M87 ha revelado una variación de su orientación

El primer agujero negro captado en imagen se tambalea, Europa Press, 23 September 2020

Un análisis de cuatro años de archivos sobre el agujero negro supermasivo en el centro de la galaxia M87, que se logró fotografiar en 2019 en absoluta primicia, ha revelado una evolución turbulenta.

La sombra de M87* se tambalea, y eso sorprende a los científicos, ABC, 23 September 2020

El mismo equipo que hace un año mostró al mundo la primera imagen de un agujero negro ha descubierto que su sombra está «bamboleándose» y ha girado de forma significativa durante los diez últimos años

Nederlaands

Het licht rond het beroemde zwarte gat blijkt te dansen en deinen, George van Hal, de Volkskrant, 24 September 2020

Het beeld nestelde zich vorig jaar direct in het publieke bewustzijn: de eerste foto van een zwart gat, een voorwerp zo zwaar dat zelfs het licht niet aan zijn zwaartekracht kan ontsnappen. Nieuw onderzoek laat zien dat het licht rond het kosmisch zwaargewicht een beetje wiebelt.

Looking sharper, blobs become filaments: RadioAstron Observations of 0836+710

Zoom into the blazar 0836+710.  RadioAstron observations show the plasma blobs becoming filaments.

September 4, 2020

A new study published in the present issue of Astronomy & Astrophysics shows the striking improvement in resolution provided by the space-VLBI mission RadioAstron.  The work is based in a study made in the framework of the PhD thesis of Laura Vega-García, performed at the MPI für Radioastronomie.  The RadioAstron images reveal a wealth of structural detail in the jet of S5 0836+710 on angular scales ranging from 0.02 mas to 200 mas. Brightness temperatures in excess of 1013 K are measured in the jet, requiring Doppler factors of ≥100 for reconciling them with the inverse Compton limit.  Furthermore, several oscillatory patterns are identified in the ridge line of the jet and can be explained in terms of the Kelvin–Helmholtz (KH) instability.  For more information, check here. 

Binary super massive black hole and jet activity in the quasar OJ 287

27 July 2020

A team of  astronomers led by S. Komossa from the MPI für Radioastronomie has observed a very bright X-ray–UV–optical outburst of OJ 287 in 2020 April–June, the second brightest since late 2015. The outburst is predominantly powered by jet emission.  The study reports evidence for reprocessing around the iron region in the source core, consistent with an absorption line.  If confirmed, it implies matter in outflow at a tenth of speed light.  The monitored source brigthness shows multiple episodes of flaring or dipping with a total amplitude of variability of one order of magnitude over the last four years prior to the 2020 outburst.  This outburst is consistent with an after-flare predicted by a binary black hole model, where the disc impact of the secondary black hole triggers time-delayed accretion and jet activity of the primary black hole.  This work is presented in the latest issue of the British journal Monthly Notices of the Royal Astronomical Society, see the publication here. 

The first picture of a black hole, at the Deutsches Museum Bonn

The first picture of a black hole, at the Deutsches Museum Bonn

June 29, 2020
Andrea Niehaus, director of the Dt. Museum Bonn, received on June 24th, 2020 the picture of the black hole in M 87 from the chairman of the Event Horizon Telescope Collaboration, J. Anton Zensus, director at the MPI für Radioastronomie.

Picture: © Deutsches Museum Bonn, Eric Lichtenscheidt more

High-energy neutrinos originate in black-hole powered jets in active galactic nuclei

May 13, 2020

A team of astrophysicists including Yuri Y. Kovalev, affiliated to the MPI für Radioastronomie and Bessel Award of the Alexander von Humboldt foundation, have come close to solving the mystery of where high-energy neutrinos come from in space. The team compared the data on the elusive particles gathered by the Antarctic neutrino observatory IceCube and on long electromagnetic waves measured by radio telescopes. Cosmic neutrinos turned out to be linked to flares at the centers of distant active galaxies, which are believed to host supermassive black holes. As matter falls toward the black hole, some of it is accelerated and ejected into space, giving rise to neutrinos that then coast along through the universe at nearly the speed of light.  These results are published in the last issue of The Astrophysical Journal, see the publication here, and a press release from the Moscow Institute of Physics and Technology here.

Jet shapes in active galactic nuclei dissected: changing from parabolic to conical shape and its physical implications

16 April 2020

A team of astronomers led by Yuri Y. Kovalev from Moscow (Lebedev & MIST), also associated to the MPI für Radioastronomie, has presented a work on ten active galactic nuclei in the close universe (redshift smaller than 0.07) displaying a transition from a parabolic to conical shape.  They infer that the geometry transition may be a common effect in AGN jets, and observed only when sufficient linear resolution is obtained.  This break occurs at distances of hundred thousand to one million gravitational radii from the nucleus.  More in detail, this means that the jet shape transition happens when the bulk plasma kinetic energy flux becomes equal to the Poynting energy flux, while the ambient medium pressure is assumed to be governed by Bondi accretion. In general, the break point may not coincide with the Bondi radius.  The results are presented in the online version of the journal Monthly Notices of the Royal Astronomical Society, available here.

Something is Lurking in the Heart of Quasar 3C 279

Something is Lurking in the Heart of Quasar 3C 279

April 07, 2020
First Event Horizon Telescope Images of a Black-Hole Powered Jet more

You can find this video on YouTube. Click on the image to be redirected there.

EHT zoom into 3C 279 reveals inner structure and jet proper motions

https://www.youtube.com/watch?v=DkULWfD5nY8

Media coverage on 3C 279 Press Release (selection)

Printed Media

English

April 7, 2020, "Blowtorch of the Gods Captured by Black Hole Image Makers", New York Times, by Dennis Overbye (quoting J.Y. Kim)

Astronomers have given us a look into the engine compartment of a quasar.

(Note: the article contains several incorrections; the team analysing M 87 and 3C 279 is the same, namely, the EHT collaboration, this publication was led by Jae-Young Kim; 3C 279 was not a calibrator but a target source in a project led by Thomas P. Krichbaum)

Forbes, 2020/04/08, "Beyond the Black Hole: The Event Horizon Telescope Solves a Quasar Mystery We Didn't Know It Existed", by Ethan Siegel (quoting T.P. Krichbaum)

Almost exactly one year ago today, the Event Horizon Telescope collaboration released the first-ever image of a black hole's event horizon. Its publication marked the first time that we'd ever directly detected a region of space where so much matter was concentrated into such a tiny volume that nothing, not even light, could escape from it.

During that same observing campaign, which took place simultaneously across eight different astronomical observatories on Earth, a number of other targets were also imaged, including the quasar 3C 279. With the unprecedented resolution of the Event Horizon Telescope, the origin of this incredibly powerful cosmic jet was revealed for the first time. Although it agrees with what was theoretically predicted, the details are spectacular in an entirely new way.

April 07, 2020, "Event Horizon Telescope spots weird black-hole jet mystery inside quasar", Space.com, by Meghan Bartels (Quoting J.Y. Kim)

At the same time the Event Horizon Telescope was gathering data to create the first-ever image of a black hole, it was also observing an even stranger object.

That object was a quasar, a pair of jets full of super-fast material shooting out from near a supermassive black hole. And the Event Horizon Telescope data suggested that those jets aren't working the way scientists had expected them to, with confusing kinks at their base.

April 07, 2020, Discover, "Event Horizon Telescope Looks Into a Black Hole's Jet", by Alison Klesman (including quotes of J.Y. Kim and J.A. Zensus)

A violent quasar reveals a mystery lurking at its center, thanks to high-resolution images that were never before possible.

April 7, 2020, "Evert Horizon Telescope finds bent jet near black hole", Sky & Telescope, by Camille M. Carlisle (quoting J.Y. Kim)

Observations from the worldwide network of radio telescopes show the fire hose of plasma shooting from a distant galaxy does something strange near its source.

April 8, 2020, "Scientists photograph jet stream cranked by black hole", in World Today News (quoting J.Y. Kim)

German

April 7, 2020, "Forscher fotografieren erstmals Jet eines Schwarzen Lochs", Süddeutsche Zeitung, by Marlene Weiß (includes quotes of T.P. Krichbaum)

Vor einem Jahr wurde das erste Bild eines Schwarzen Lochs veröffentlicht.  Jetzt gibt es ein zweites. Es zeigt Materie, die dem Loch knapp entkommen ist.

Ziemlich genau ein Jahr nachdem das erste direkte Bild eines Schwarzen Lochs um die Welt ging, legen die Forscher von der internationalen Event-Horizon-Kollaboration nach: Am Dienstag veröffentlichten sie eine zweite Aufnahme, die auf Daten der gleichen Messrunde beruht. Sie zeigt ein Objekt namens 3C279. Es ist rund hundertmal weiter entfernt als die Galaxie M87, in der das erste Schwarze Loch fotografiert wurde - aber auch um ein Vielfaches heller. Es handelt sich dabei um einen Quasar: Eine Galaxie, in deren Zentrum sich ein Schwarzes Loch mit etwa einer Milliarde Sonnenmassen befindet. Und das, während es sich eifrig Materie einverleibt, enorm starke Radiostrahlung aussendet.

April 7, 2020, "Vermeintlich schneller als das Licht", Tagesspiegel, by Otto Wöhrbach (including quotes of J.Y. Kim, E. Ros, and J.A. Zensus)

Supermassive Schwarze Löcher schießen ionisierte Gase rasend schnell ins All. Von diesem „Jet“ gibt es jetzt so scharfe Bilder wie nie zuvor.

April 8, 2020, "Kosmische Fontänen", Die Welt, by Norbert Lossau (including quotes of J.Y. Kim)

Vor einem Jahr, am 10. April 2019, präsentierten Wissenschaftler erstmals das direkte Abbild eines Schwarzen Loches in der Nachbargalaxie Messier 87. Das galt als wissenschaftliche Sensation. Nun gelang dem gleichen Forscherteam, der sogenannten Event-Horizon-Teleskop-Kollaboration, die Abbildung eines Materiestrahls, der mit fast Lichtgeschwindigkeit von einem super-massereichen Schwarzen Loch ausgestoßen wird. Astrophysiker bezeichnen solche Fontänen aus ionisiertem Gas kurz und knapp als „Jets“. Veröffentlicht haben die Physiker unter Leitung von Jae-Young Kim vom Bonner Max-Planck-Institut für Radioastronomie ihre Ergebnisse in der Fachzeitschrift „Astronomy & Astrophysics“.

April 08, 2020, "Faszinierende Aufnahme: Schwarzes Loch schleudert Plasmastrahl ins All", Futurezone.at

Forschern gelangen Bilder von sogenannten Jets in einem Schwarzen Loch.

Italian

April 7, 2020, "Dopo quella del buco nero arriva la prima immagine di un getto relativistico", Agenzia Italiana 

La tecnica utilizzata da EHT, chiamata interferometria a base molto lunga (VLBI), ha permesso agli scienziati di studiare la morfologia su scala fine del getto vicino alla sua base, dove si pensa abbia origine un'emissione di raggi gamma molto variabile.

April 7, 2020, "Fotografato uno dei fenomeni più potenti del cosmo", Sky tg24

Lo scatto, ottenuto con un livello di dettaglio inedito, ha immortalato per la prima volta un getto di plasma emesso da un buco nero supermassiccio al centro di una galassia, 3C 279, situata nella costellazione della Vergine.

Spanish

April 7, 2020, "Captan la imagen de un chorro de materia emergiendo de un agujero negro", Agencia Efe (including quote from J.Y. Kim)

Un chorro de materia a alta velocidad emergiendo de un agujero negro supemasivo es la nueva imagen captada por el Telescopio Event Horizont (EHT), el mismo que hace un año dio a conocer la primera fotografía de un agujero negro.

La observación proporcionó al equipo internacional de investigadores, entre ellos españoles, alguna sorpresa sobre la forma de ese tipo de chorros y que se recoge en un estudio que publica Astronomy & Atrophysics.

April 7, 2020, "Algo está al acecho en el corazón del cuásar 3C 279", EuropaPress Ciencia (including quote of J.Y. Kim)

La colaboración EHT (Event Horizon Telescope), que publicó la primera imagen de un agujero negro hace un año, ha revelado en el distante cuásar 3C279 los mejores detalles vistos hasta ahora en un chorro producido por un agujero negro supermasivo.

French

April 9, 2020, "Un an après le trou noir M87*, l'EHT livre l'image d'un jet de quasar", Futura News, by Laurent Sacco

Un après l'obtention de la première image d'un trou noir, les membres de la collaboration Event Horizon Telescope (EHT) révèle celles d'un jet associé à un quasar. La résolution obtenue bat un record et montre des détails inédits.

Hungarian

April 8, 2020, "A fekete lyuk árnyéka után egy kvazár plazmanyalábját bontotta fel az Eseményhorizont Teleszkóp", by Krisztina Gabanyi (MPIfR alumna)

Tavaly áprilisban ismerhette meg a világ az első szupernagy tömegű fekete lyukról készített képet, most pedig egy másik különleges égi forrásnak az Event Horizon Telescope (EHT) méréseiből készült rádiótérképében gyönyörködhetünk. 2017 áprilisában ugyanis nem csak az M87 jelű galaxis középpontjában található fekete lyukat figyelték meg ezzel a rádióantenna-hálózattal, hanem a 3C 279 jelű kvazárt is.

Located the site of emission of high-energy gamma rays in the blazar TXS 2013+370

17 February 2020

An international team of astronomers led by the doctoral researcher Efthalia Traianou from the MPI für Radioastronomie has identified the location of the gamma-ray emission in the blazar jet TXS 2013+370.  The published results report very-long-interferometry observations of the blazar in the period 2002-13 at four wavelengths up to the challenging 3.5 mm addressed by the Global mm-VLBI Array (GMVA).  The images revealed the existence of a spatially bent jet, described by co-existing moving emission features and stationary features. New jet features, lare observed to emerge from the core, accompanied by flaring activity in radio/mm- bands and γ-rays.  The work infers that the high energy emission is produced at a distance of the order of about 3 lt-year from the jet apex, suggesting that the seed photon fields for the external Compton mechanism originate either in the dusty torus or in the broad-line region.  These results are published in the present issue of the Astronomy & Astrophysics journal, see the original work here. 

A wobbling jet with a two-year period

12 February 2020

The quasar PG 1553+113 is the first one showing an approximately two-year quasi-periodic pattern in its γ-ray light curve, which is also revealed at optical frequencies.  A study by an international team of radio astronomers led by the MPIfR scientist Rocco Lico has analysed very-long-baseline interferometry observations of the source with a two-month cadence at three bands.  The study shows  a core-dominated source with a limb-brightened jet structure whose position angle varies in time in the range of 40° to 60°.  The core region polarisation percentage varies in the range  of a few percent, and the polarisation angle varies from being roughly parallel to roughly transverse to the jet axis.  Although the jet wobbling motion indicates that geometrical effects can produce an enhanced emission through  Doppler boosting modulation, additional mechanisms are required in order to account for the quasi-periodic variability patterns observed in γ-rays.  Further details of this work are presented in the original publication at Astronomy & Astrophysics, see here.

Effelsberg observes methanol emission in nearby galaxies

17 January 2020

A team of astronomers led by the MPIfR PhD candidate Pedro Kumire has observed 36 GHz emission of methanol (CH3OH) in nearby galaxies using the Effelsbeg 100-m radio telescope.  Emission was detected in Maffei 2 (at a distance of 19.6 million lt-yr) and IC 342 (at 11.4 million lt-yr) at 36 GHz (4−1 → 30 E transition), but not at 44 GHz transition.  Upper limits were reported for M 82, NGC 4388, NGC 5278, and Arp 220.  These results are published in Astronomy and Astrophysics, for more detail, check here.

The neutrino detection in the blazar TXS 0506+056, linked to superluminal expansion and  limb brigthening in the sub-parsec scale of the source

2 January 2020

The first letter of the Astronomy & Astrophysical journal in the 2020s, led by Eduardo Ros of the MPIfR, reports on the rapid expansion of the centre of the blazar TXS 0506+056, based on millimetre VLBI observations performe with the VLBA.  During the months after the neutrino event associated with this source, the overall flux density was showing a steady increase, happening solely within the core. Notably, the core expands in size with apparent superluminal velocity during these six months so that the brightness temperature drops by a factor of three despite the strong flux density increase.  The radio jet of TXS 0506+056 shows strong signs of deceleration and/or a spine-sheath structure in the innermost region. This structure is consistent with theoretical models that attribute the neutrino and gamma-ray production to interactions of electrons and protons in the highly relativistic jet spine with external photons originating from a slower moving jet region. Proton loading due to jet-star interactions in the inner host galaxy is suggested as the possible cause of deceleration.  Further details can be found in the original publication here.

The first image of a black hole, scientific highlight of 2019 and even of the 2010s

2 January 2020

The announcement and publication of the first image of a black hole in April 2019, with substantial contribution of the MPIfR and its Radio Astronomy/VLBI department, has been highlighted by different media as one of the major scientific discoveries of the last year and of the 2010s.  Here we provide some of the links reporting this fact.

Business Insider, 18 November 2019: The most mind-boggling scientific discoveries of 2019 include the first image of a black hole, a giant squid sighting, and an exoplanet with water vapor

The unprecedented photo shows the supermassive black hole at the center of the Messier 87 galaxy, which is about 54 million light-years away from Earth. The black hole’s mass is equivalent to 6.5 billion suns.

Though the image is somewhat fuzzy, it showed that, as predicted, black holes look like dark spheres surrounded by a glowing ring of light.

Scientists struggled for decades to capture a black hole on camera, since black holes distort space-time, ensuring that nothing can break free of their gravitational pull — even light. That’s why the image shows a unique shadow in the form of a perfect circle at the center.

BR 31 December 2019 (in German): Space Highlights 2019 - The Sensation of the Year: first Image of a Black Hole (Weltraum-Rückblick 2019 - Die Sensation des Jahres: erste Aufnahme eines Schwarzen Lochs)

2019 hatte für Astronomie-Fans einiges zu bieten: Den weltweiten Run zum Mond, das erste Foto eines Schwarzen Lochs und gegen Jahresende den Merkurtransit. Gehen Sie mit uns auf die Reise zu den magischen Momenten im Weltall!

wissenschaft.de, 19 December 2019 (in German): Top highlight of the year: the first picture of a black hole (Top-Highlight des Jahres: Das Foto eines Schwarzen Lochs), by Nadja Podbregar

Jedes Jahr kürt das Fachmagazin „Science“ die zehn Highlights des Jahres – und lässt so das wissenschaftliche Jahr noch einmal Revue passieren. 2019 hat die Jury das erste Foto eines Schwarzen Lochs an die Spitze gesetzt – einen astronomischen Meilenstein, der lange als unmöglich galt. Das Bild macht erstmals den dunklen Schatten des Schwarzen Lochs, umgeben von einem hellen Lichtring ausglühenden Gasen, sichtbar. Ebenfalls unter den Highlights des Jahres sehen die „Science“-Editoren unter anderem die erste Gesichtsrekonstruktion eines Denisova-Menschen, einen Quantencomputer, der den weltbesten Supercomputer geschlagen hat und eine wirksame Therapie gegen Ebola.

ORF.at, 30 December 2019 (in German):  The Astro-Higholights of the Year - Moon Missions, Planet Hunter, and the first "real" Picture of a Black Hole (Die Astrohighlights des Jahres - Mondmissionen, Planetenjäger und das erste „echte“ Bild eines Schwarzen Lochs) by Annelise Haika and Stefan Walinger

Das spektakulärste Bild des Jahres bot den ersten direkten visuellen Nachweis für ein supermassereiches Schwarzes Loch. Die Messungen dazu wurden bereits 2017 mit einem erdumspannenden Netzwerk aus acht Radioteleskopen gemacht. Es dauerte zwei Jahre, die enormen Datenmengen dieses „Ereignishorizontteleskops“ auszuwerten.

RTBF, 31 December 2019 (French): Picture of the Black Hole, Homo Luzonensis... 7 Scientific Discoveries which marked 2019 (Photo du trou noir, l'homo luzonensis... 7 découvertes scientifiques qui ont marqué 2019)

L’année 2019 a été riche en découvertes scientifiques, découvrez-en une sélection de notre rédaction.  

Première photo du trou noir

En avril, des astronomes du monde entier, réunis sous le projet Event Horizon Telescope, ont présenté au monde la première image d’un trou noir lors de six conférences simultanées. Il s'agit du trou noir au centre de la galaxie M87 à 55 millions d'années-lumière de la Terre.

Le Figaro, 25 December 2019 (in French): Black Hole, Homeopathy... The five events which marked science in 2019.  Le Figaro delivers its selection of the key moments of science this year, and the ones expeced for 2020.  (Trou noir, homéopathie... Les cinq événements qui ont marqué la science en 2019.  Le Figaro livre sa sélection des moments-clés de la science cette année... et ceux qui sont les plus attendus pour 2020)

Portrait d’un trou noir

C’est sans conteste la plus grande prouesse scientifique de l’année, et tout simplement la première fois que l’on a pu «voir» un trou noir «pour de vrai».

Pour réaliser ce cliché stupéfiant dévoilé en avril, il aura fallu que tous les plus grands radiotélescopes du monde entier se coordonnent et pointent en même temps vers le trou noir central supermassif niché au cœur de la galaxie elliptique supergéante M87. On distingue ainsi l’ombre de cet ogre, au centre de l’image, qui se détache sur un fond lumineux constitué de gaz et de poussières s’apprêtant à s’effondrer dans sa gueule béante. Magique.

ABC, 19 December 2019 (in Spanish): The black hole in M 87, a historical image (El agujero negro en M 87, una imagen para la historia), invited article by A. Alberdi (MPIfR alumnus) & J.L. Gómez

La revista Science ha seleccionado la primera imagen de un agujero negro como el hito científico más relevante del año. Los investigadores Antxon Alberdi y José Luis Gómez, que participaron en su obtención, hablan sobre su importancia

El Periódico, 28 December 2019 (in Spanish): Black Hole, Time Travel, and Climate Clocks: that was the most-read science this year in our newspaper (Agujeros negros, viajes en el tiempo y despertadores climáticos: esta ha sido la ciencia más leída del año), by Valentina Raffio

La primera imagen de un agujero negro destaca como uno de los avances más destacados del 2019

SINC Agency, 19 December 2019 (in Spanish): The ten scientific achievements in 2019 (Los diez avances científicos de 2019)

La revista Science ha seleccionado los diez avances científicos más importantes de este año. En las primeras posiciones, la fotografía del agujero negro, el rostro de los denisovanos y la explicación de la desaparición de los dinosaurios. Además, la publicación señala tres grandes tareas pendientes de la ciencia.

Vietnam News, 26 December 2019: Top 10 world events of 2019 voted by Vietnam News Agency: First ever black hole image released

The Event Horizon Telescope Collaboration on April 10 released the first ever picture of a black hole. The black hole, that is 6.6 billion times bigger than the Sun, was found in a distant galaxy called M87, about 55 million light-years from the Earth.

It was captured by a global network of eight telescopes, from Hawaii (the US) and Atacama (Chile) to the South Pole and Europe. The historic discovery is said to confirm Albert Einstein’s theory of general relativity.

MEAWW, 25 December 2019: First-ever image of a black hole that stunned the world is Science’s 2019 Breakthrough of the Year, by Mihika Basu

Black holes are very small by cosmic standards and by definition emit no light, which is why until recently few astronomers imagined such an image was even possible.

In April 2019, the world saw the first-ever image of a black hole. That’s when an international team of astronomers released a startling close-up image of a black hole’s “shadow,” showing a dark heart surrounded by a ring of light created by photons zipping around it.

Now honoring this feat that was once considered impossible, Science journal has named the Event Horizon Telescope or EHT’s image of a supermassive black hole as its 2019 Breakthrough of the Year.



Predicting Cherenkov telescope detections from Active Galactic Nuclei

14 October 2019

The MPIfR astronomer Roberto Angioni publishes today at the journal Astroparticle Physics a study of the detection prospects for the Cherenkov Telescope Array (CTA).  By simulating observations of forty-one γ-ray radio galaxies, extrapolating their Fermi-LAT spectrum into the TeV energy range assuming different spectral shapes, the author predicts that the CTA will detect eleven new TeV radio galaxies with an observational campaign of fifty hours per source. This would increase the sample of very-high-energy radio galaxies by a factor of three.  More details, in the original publication here.

Neutrino produced in a cosmic collider far away

Neutrino produced in a cosmic collider far away

October 02, 2019
Link between IceCube neutrino event and distant radio galaxy resolved more

Gamma-ray emission at 140 light years from the jet base in the quasar 3C 279

23 September 2019

An international team of astronomers, led by Víctor M. Patiño-Álvarez, affiliated to the MPI für Radioastronomie and now leader of a partner research group at the Mexican Instituto Nacional de Astrofísica Óptica y Electrónica in Puebla has presented a study of the radio-gamma connection in the quasar 3C 279.  A comparison of the flux variability in jet features with the gamma-ray variability suggests that the gamma-ray variability is correlated with a particular region downstream from the observed base of the jet at a distance of about 140 lt-yr.  This feature shows an apparent superluminal velocity of about 3.7 times the speed of light, implying that one of the gamma-ray emission zones is not stationary.  Further details can be found in the original publication at the Astronomy & Astrophysics journal here. 

Event Horizon Telescope Collaboration Announces New Management Team

17 September 2019

Professor Anton Zensus, the Chairman of the Board of the Event Horizon Telescope Collaboration, announces the search for a new EHT director and changes to the EHT management, which become effective on September 17, 2019.

The US National Science Foundation has announced the funding of a $12.7M Mid-Scale research innovation grant (MSRI), to develop technologies and techniques that will help to create transformational capabilities for a next-generation Event Horizon Telescope array, envisaged for the second half of the 2020s. Shep Doeleman is PI of this award, and several other US institutions are participating. 

“The development of long-term technologies and techniques is an important step towards taking the Event Horizon Telescope into the future. There are none more qualified to lead such a visionary effort than Shep, and we are looking forward to working with him over the coming months to help coordinate the MSRI activities with related work across the EHT collaboration” notes Anton Zensus.

The EHT Board recognizes Shep Doeleman as the Founding Director of the Event Horizon Telescope, acknowledging his leadership to the phenomenal success of the EHT, which led to the first image of a black hole in the galaxy Messier 87.

"The spectacular M87 EHT results have surpassed our wildest expectations, and I am deeply proud of what we achieved as a team.  Now the question one hears the most is "what's next?", and the next-generation EHT initiative is the exciting clear response. I look forward to continuing to support the EHT, and am delighted to focus on this new direction." says Shep Doeleman, EHT Founding Director.

The Board will immediately initiate the search to fill the now vacant position of EHT Director, while supporting continuity of the activities of the project through a series of management changes. 

* Mike Hecht, Associate Director at Haystack Observatory, will serve as Deputy Project Director;  

* Geoff Bower of the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), the vice Chair of the EHT Science Council, will serve as Project Scientist. 

* Remo Tilanus of Leiden Observatory will serve as Operations Manager. 

* David James of the Harvard-Smithsonian Center for Astrophysics  will continue to provide project management support to the Team. 

“The EHT Management Team is enhanced to address the evolving management and communication needs of our collaboration, which has seen rapid growth in membership, and increasing complexity in operations, scientific and development activities. Shep has graciously offered to continue to advise the Management Team during the transition period” adds Zensus.

US NSF MSRI Award: “Next Generation Event Horizon Telescope Design” #1935980

Event Horizon Telescope webpage

Further information:

Prof. Dr. J. Anton Zensus

Dr. Colin J. Lonsdale

Prof. Dr. Eduardo Ros

EHT Board Chairman

EHT Board Vice-Chairman

 EHT Board Executive Secretary

MPI für Radioastronomie, Bonn, Germany

MIT Haystack Observatory, Westford, MA, USA

MPI für Radioastronomie, Bonn, Germany

azensus@mpifr-bonn.mpg.de

cjl@haystack.mit.edu

ros@mpifr-bonn.mpg.de

Tel. +49 228 525 378

Tel. +1 617 715 5575

Tel. +49 228 525 125
Breakthrough Prize in Fundamental Physics to be awarded to the Event Horizon Telescope Collaboration

Breakthrough Prize in Fundamental Physics to be awarded to the Event Horizon Telescope Collaboration

September 05, 2019
The award recognizes the first image of a black hole with an Earth-sized alliance of telescopes more

A Test of General Relativity at The Galactic Center

25 July 2019

In a detailed study of a star orbiting the supermassive black hole at the center of our Galaxy, researchers report that Einstein’s theory of general relativity (GR) accurately describes motion around this massive structure. Tuan Do, Andrea Ghez and their colleagues including Gunther Witzel from the Max Planck Institute for Radio Astronomy in Bonn, Germany, report novel spectral data and expanded analyses. The findings are presented in this week’s issue of the magazine „Science“ (UCLA Press Release, 25 July 2019).   [more]

Gamma-ray emission in radio galaxies under the VLBI scope

15 July 2019

The POLAMI Collaboration has published a study, led by the MPI für Radioastronomie researcher R. Angioni, of the gamma-ray emission of Southern radio galaxies.  These results are published in the last issue of the Astronomy & Astronomy journal.  The study shows that the brightness of the core of the radio sources correlates with the gamma-ray emission, as seen in blazars.  However, the gamma-ray luminosity does not show dependence with the compact radio emission of the core of the galaxies, which is a common indicator of Doppler boosting.  The authors conclude that the gamma-ray emission in radio galaxies is not driven by orientation-dependent effects, as in blazars, according with the unified model of jetted active galactic nuclei. More information is available here.

The large gamma-ray flare of the flat-spectrum radio quasar PKS 0346−27

12 July 2019

A multi-messenger study led by R. Angioni of the MPI für Radioastronomie, published in the present issue of Astronomy & Astrophysics, reports on the long- and short-term flux and spectral variability from the radio quasar PKS 0346−27, producing gamma-ray light curves with different time binning.  Evidence of short-time scale variability down to 90 min is presented.  The source shows remarkable properties during an outburst in May 2018, and is a promising target for future ground-based Cherenkov observatories.  More information is available at the original publication here. 

The gamma-loud radio galaxy 3C 264

4 July 2019

A team of astronomers led by the astronomer B. Boccardi of the MPI für Radioastronomie publishes in the latest issue of Astronomy & Astrophysics a high-resolution radio study of the gamma-ray emitting galaxy 3C 84.  The authors present a adio and X-ray analysis of the jet in 3C 264. They determine the main physical parameters of the parsec-scale flow and explore the implications of the inferred kinematic structure for radiative models of this γ-ray emitting jet.  The publication suggests that the high-energy emitting region is located at the end of the acceleration zone of the jet, either in the jet layer or in the spine.  Further information can be found here.

A study of the physics of the complex jet in the blazar S5 0836+710

3 July 2019

The last issue of the journal Astronomy & Astrophysics reports the results of a thorough analysis of the jet profile of the high-resolution images of the blazar S5 0836+710.  The study is led by the MPI für Radioastronomie researcher L. Vega García.  The authors ran numerical calculations of stability of a relativistic, sheared jet over a range of different jet parameters, based on the assumption that the observed structures are generated by growing Kelvin–Helmholtz instability modes.  The results yield physical parameters of the jet, with a Lorentz factor of 12 and an internal Mach number of 12, as well as a jet-to-ambient medium density of 1/1000.  More details can be found in the original publication here. 

Astronomers Capture First Image of a Black Hole

Astronomers Capture First Image of a Black Hole

April 10, 2019
MPIfR and IRAM contribute to groundbreaking observations of the gargantuan black hole at the heart of distant galaxy Messier 87 more

Media coverage (selection): Astronomers capture the first image of a black hole

Compilation of newspaper covers from April 11th, 2019 (by Eduardo Ros)

Printed media

English:

April 13, 2019: Staring into the Abyss: Astronomers take the first picture of a black hole, The Economist

April 10, 2019: "Darkness Visible, Finally: Astronomers Capture First Ever Image of a Black Hole", NYT Dennis Overbye

Astronomers at last have captured a picture of one of the most secretive entities in the cosmos.

April 10, 2019: Peering down the cliff of infinity: the first image of the event horizon of a black hole, Bad Astronomy: Phil Plait, SyFy Wire

April 10, 2019: "An astounding coincidence with theory", Interview with J. Anton Zensus, Max Planck Society

April 10, 2019: First-ever picture of a black hole unveiled, National Geographic, by Nadia Drake

Using a telescope the size of the planet, astronomers have captured the first image of this space oddity. Here's why that matters.

April 10, 2019: Scientists Unveil First Black Hole Image, Sky & Telescope, by Camille M. Carlisle

The Event Horizon Telescope collaboration has reconstructed the shadow of a supermassive black hole.

April 10, 2019: Astronomers Capture First-Ever Image of a Supermassive Black Hole, Smithsonian Magazine, Jay Bennet

The Event Horizon Telescope reveals the silhouette of a black hole at the center of a galaxy 55 million light-years away.

April 10, 2019: How the Event Horizon Telescope imaged an invisible black hole, Astronomy, by Erika K. Carlson

Hint: it's much harder than it sounds.

April 10, 2019: For the first time, you can see what a black hole looks like, Science, Daniel Clery

German:

May 14, 2019: Das erste Foto eines Schwarzen Lochs, Spektrum der Wissenschaft, S. Britzen & A. Müller

Endlich! Das schon seit Jahren erwartete, erste direkte Bild eines Schwarzes Lochs ist nun mit einem globalen Netzwerk aus Radioteleskopen gelungen. Das spektakuläre »Foto« gibt den Blick frei in das Herz der Galaxie Messier 87 in 55 Millionen Lichtjahren Entfernung. Dort sitzt eines der größten bekannten Schwarzen Löcher, das Materie verschlingt, diese zum Leuchten bringt und so das Loch ­sichtbar werden lässt.

April 21, 2019: Ein Fleck, hinter dem sich ein Stück Ewigkeit verbirgt, Süddeutsche Zeitung, comment by Marlene Weiß

Das Foto vom Schwarzen Loch wird wohl nie einen praktischen Nutzen haben. Doch es zeigt, dass der Mensch die Grenzen seiner Vorstellungskraft überschreiten kann. In Zeiten, in denen der Homo sapiens seinen Planeten zugrunde richtet, ist dies von besonderer Bedeutung.

April 19, 2019: Jenseits der Grenze, Süddeutsche Zeitung, Comment by Marlene Weiß

Die Bilder vom Schwarzen Loch sind faszinierend. Sie zeigen, dass Menschen etwas sichtbar machen können, das ihre Welt überschreitet. Was bedeutet das?

April 17, 2019: Entdeckersehnsucht, FAZ, Comment by Sibylle Anderl (IMPRS alumna)

Hinter großen wissenschaftlichen Durchbrüchen stehen heute meist Hunderte von Forschern. Dass unsere Sehnsucht nach einem entscheidenden Einzelentdecker dennoch groß ist, konnte man jüngst erneut beobachten.

April 15, 2019: Ein historischer Schatten, FAZ, Sibylle Anderl (IMPRS alumna)

Schwarze Löcher galten lange als Inbegriff des Unbeobachtbaren. Bevor nun dem EHT erstmalig eine direkte Abbildung gelangt, stellte sich lange die Frage nach ihrer Existenz.

April 13, 2019: Zwei Jahre bis zum Bild, FAZ, Sibylle Anderl (IMPRS alumna), including quotes of J. Anton Zensus

Die Beobachtung mit dem „Event Horizon Telescope“ ist ein internationaler Erfolg. Zum ersten Mal konnten Wissenschaftler ein Schwarzes Loch direkt visuell nachweisen. Doch der Schnappschuss wurde lange Zeit im Voraus geplant.

Cover Page from weekly magazine "Der Spiegel", April 13, 2019

April 12, 2019: Was uns schwarze Löcher über die Geheimnisse des Universums verraten, Der Spiegel, Johannes Grolle (includes interviews with J. Anton Zensus and Thomas P. Krichbaum)

Das erste Bild eines schwarzen Lochs erlaubt tiefe Einblicke in das Wesen des Universums. Die Schwerkraftmonster bergen sogar den Schlüssel zu einer Art Weltformel.

April 11, 2019: Annäherung ans Schwarze Loch, Süddeutsche Zeitung, Marlene Weiß and Patrick Illinger

Was passiert, wenn man in ein Schwarzes Loch hineinfällt? Und sehen die Massemonster wirklich so aus, wie auf der nun vorgestellten Aufnahme? Antworten auf die wichtigsten Fragen.

April 11, 2019: „Wie der Eingang zur Hölle“, Der Tagesspiegel, by Ralf Nester, quoting J. Anton Zensus

Mithilfe mehrerer Radioteleskope ist es gelungen, das Zentrum der Galaxie M 87 darzustellen. Das Bild ist eine Sensation. Und entspricht den Prognosen. Leider.

April 11, 2019: "Wissenschaftlicher Durchbruch: Schwarzes Loch M87: Was auf dem Sensationsfoto zu sehen ist", Focus, Martin Odenwald (including quotes of J. Anton Zensus)

Was die Astronomen der Event Horizon Telescope (EHT) Collaboration berichten, gilt mit Fug und Recht als wissenschaftliche Sensation: Erstmals gelang es, den Ereignishorizont eines Schwarzen Lochs zu fotografieren. Damit rückten die Astronomen so nahe an das Schwerkraftmonster heran, wie es theoretisch möglich ist.

April 11, 2019: „Verblüffende Übereinstimmung mit der Theorie“, Interview with J. Anton Zensus, ScineXX Das Wissensmagazin

April 11, 2019: Sinnvoller als bemannte Missionen zum Mond, Süddeutsche Zeitung, Comment by Marlene Weiß

Das erste Foto eines Schwarzen Lochs zeigt eine Welt, in der Zeit und Raum ihre Bedeutung verlieren. Das ist nicht nur faszinierend, es bringt auch wichtige wissenschaftliche Erkenntnisse.

April 10, 2019: So sieht ein Schwarzes Loch wirklich aus, Die Zeit, Alina Schadwinkel (including quotes of Eduardo Ros)

Sie dachten, das wisse man? Falsch. Dies ist das erste Bild eines Schwarzen Lochs. 200 Forscher brauchte es dazu und ein virtuelles Riesenteleskop, so groß wie die Erde.

April 10, 2019:  "Schatten eines Giganten", FAZ, comment by Sibylle Anderl (IMPRS alumna)

Das Event Horizon Telescope hat das erste Bild eines Schwarzen Lochs veröffentlicht. Die Beobachtung ist nicht nur wissenschaftlich wegweisend. Sie zeigt auch, dass sich die europäischen Astronomen nicht verstecken müssen.

April 10, 2019: Und es ward Licht, Spiegel Online, by Markus Becker (including quotes by Michael Kramer and Eduardo Ros)

"Es fühlt sich an, als blicke man auf die Tore der Hölle": Wissenschaftler weltweit sind begeistert vom ersten Foto eines schwarzen Lochs. Reicht das Bild für den Nobelpreis?

April 10, 2019: Forscher fotografieren erstmals Schwarzes Loch, Süddeutsche Zeitung, by Marlene Weiß

April 10, 2019: Ein Schwarzes Loch als dunkler Schatten, FAZ, by Sibylle Anderl (IMPRS alumna)

April 10, 2019: Das erste Bild eines Schwarzen Lochs, FAZ, by Sibylle Anderl (IMPRS alumna)

Dem Event Horizon Telescope ist die erste Aufnahme des „Schattens“ eines Schwarzen Lochs gelungen. Das abgebildete Objekt im Zentrum der Galaxie M87 entspricht in verblüffendem Maß den Erwartungen.

April 10, 2019: Erstes Bild von Schwarzem Loch, Die Welt (including quotes by J. Anton Zensus)

Bislang gab es von Schwarzen Löchern nur Illustrationen. Jetzt haben Astronomen das erste Bild gemacht - und sprechen von einer «unglaublichen Errungenschaft». Acht Observatorien waren für die Aufnahme notwendig.

April 10, 2019: "Von Bonner Forschern präsentiert: Das ist das erste Foto eines Schwarzen Lochs im All", Bonner Rundschau, Martin Wein (including quotes of J. Anton Zensus and Eduardo Ros)

April 10, 2019: Wissenschaftler fotografieren erstmals ein schwarzes Loch, golem.de, by Werner Pluta

Die Existenz von schwarzen Löchern war schon seit Langem vorhergesagt, bisher konnten sie aber nur indirekt nachgewiesen werden. Dem Projekt EHT ist es gelungen, mit Hilfe eines virtuellen, erdumspannenden Teleskops erstmals ein Bild eines schwarzen Lochs aufzunehmen.

April 10, 2019: Das Monster zeigt seine Zähne, Spektrum der Wissenschaft, by Robert Gast (with references to Thomas P. Krichbaum and J. Anton Zensus)

Astrophysiker bringen eines der ambitioniertesten Projekte ihrer Disziplin zum Abschluss: Sie haben erstmals ein Schwarzes Loch fotografiert. Ein Bild für die Geschichtsbücher – und das vorläufige Ende einer langen Reise.

April 10, 2019: Forscher zeigen erstmals Foto von einem schwarzen Loch, Spiegel Online, by Christoph Seidler

Ein weltweites Netzwerk von Teleskopen hat eine Beobachtung ermöglicht, auf die Astronomen seit Jahrzehnten warten: Das erste Bild von einem schwarzen Loch. Wir erklären, was zu sehen ist.

April 10, 2019: Ein Foto, das eigentlich unmöglich ist, Der Tagesspiegel, by Ralf Nestler

Ein Schwarzes Loch kann nicht abgebildet werden, theoretisch aber eine Zone drumherum. Die Pressekonferenz im Livestream.

French:

April 13, 2019: Première image d'un trou noir supermassif : des commentaires d'Aurélien Barrau, Futura Sciences, by Laurent Sacco

On l'attendait depuis un moment et cet évènement fera date dans l'histoire de l'exploration du Cosmos par l'Humanité. La première image d'un trou noir prise avec l'Event Horizon Telescope a été dévoilée et c'est celle du trou noir supermassif au cœur de la galaxie M87. Une nouvelle fenêtre sur la gravitation quantique s'ouvre peut-être, selon Aurélien Barrau.

April 10, 2019: Ce que révèle la première photo d'un trou noir, 7sur7 (including quote by J. Anton Zensus)

Une équipe de scientifiques a dévoilé mercredi après-midi, au Berlaymont, le centre névralgique de la Commission européenne à Bruxelles, la première image d'un trou noir, capturée par Event Horizon Telescope, une collaboration mondiale associant des scientifiques financés par l'Union européenne.

April 10, 2019: La première photo d’un trou noir: Einstein avait raison, souligne un chercheur, Le Soir (including quotes by J. Anton Zensus and Eduardo Ros)

Spanish:

April 14, 2019: Qué se sabe del primer agujero negro fotografiado: un "monstruo" tres millones de veces la Tierra, 20 minutos, including interview to Eduardo Ros
 

April 11, 2019: "Cazar agujeros negros desde México", NYT Albinson Linares

April 10, 2019: Un anillo luminoso rojo y amarillo: la primera foto de un agujero negro, Agencia Efe Bruselas (including quote of Eduardo Ros)

April 10, 2019: "Así se ve un agujero negro", NYT Dennis Overbye

April 10, 2019: Primera foto de un agujero negro: Una colaboración mundial, un radiotelescopio tan grande como el planeta, El Mundo, Rafael Bachiller

April 10, 2019: Esta es la primera imagen jamás tomada de un agujero negro, El País, Bruno Martín (quoting Antxon Alberdi, MPIfR alumnus)

April 10, 2019: La primera imagen de la sombra y el anillo asimétrico del agujero negro M87* gracias a EHT, La Ciencia de la Mula Francis, by Francisco R. Villatoro

April 10, 2019: Lo nunca visto: la primera foto de un agujero negro, La Vanguardia, by Josep Corbella

Radio, television, internet movies, and podcasts

English:

April 23, 2019: How to make an image of a black hole, Deutsche Welle, Social Media, short video featuring Helge Rottmann, Jan Wagner, and Eduardo Ros

How do you make an image of a black hole? Eduardo Ros at the Max Planck Institute for Radio Astronomy explains it with some helpful drawings.

April 10, 2019: Discovering the black hole: Why does it matter?, Interview to J. Anton Zensus, News China TV

Discovering the black hole: J. Anton Zensus explains why an international team conducts studies on the elusive celestial object

April 10, 2019: First ever black hole image released, Pallab Ghosh, BBC

April 10, 2019: The first image of a black hole: A three minute guide, nature video

April 10, 2019: Here is the first photo of a black hole, PBS, Nsikan Akpan

German:

April 18, 2019: Schwarze Löcher - Was wir jetzt darüber wissen, arte.tv Xenius, including interviews with J. Anton Zensus, Michael Kramer, and others

April 15, 2019: Schwarzes Loch: Wie die erste Aufnahme gelang, BR Gut zu Wissen, including interviews with Silke Britzen and J. Anton Zensus

April 11, 2019: Astrophysikerin über Bild eines Schwarzen Lochs: „Das ist ein Schlüssel zu einer neuen Physik“, Interview to Silke Britzen, DeutschlandFunk Kultur

April 11, 2019: Das Schwarze Loch, Claudia Sarre, NDR Studio Washington DC (Audio)

April 11, 2019, Astronomen gelingt erstes Bild von Schwarzem Loch, radiohamburg.de

April 11, 2019: Wie entsteht ein Schwarzes Loch?, Video by Patrick Illinger, süddeutsche.de

April 10, 2019: Sensation in der Astrophysik: Foto zeigt Millionen Lichtjahre entferntes Schwarzes Loch, Tagesthemen (min 20:40-23:50, includes interview with J. Anton Zensus)

April 10, 2019: Durchbruch im Weltall - Foto vom Schwarzen Loch, ZDF heute journal (min 00:50-08:40, with Harald Lesch, MPIfR alumnus and member of board of trustees)

April 10, 2019: Forschern gelingt erste Aufnahme von Schwarzem Loch, ARD tagesschau (min 08:50-10:47, includes interview with J. Anton Zensus)

April 10, 2019: Erste Aufnahmen von schwarzem Loch, ZDF heute (min 13:13-15:15)

April 10, 2019: Forscher präsentieren Aufnahmen eines Schwarzen Loches, Dirk Lorenzen (member of MPIfR board of trustees) und Reinhart Brüning, DeutschlandFunk

April 10, 2019: Erstes Bild von Schwarzem Loch veröffentlicht, tagesschau.de

April 10, 2019: Welt sieht erstmals ein Schwarzes Loch - Kai Stoppel, n-tv.de

April 10, 2019: „Wie ein Ring mit ein paar ordentlichen Klunkern dran“, Dirk Lorenzen and Nicole Dittmer, DeutschlandFunk Kultur

April 10, 2019: Phantom des Universums, 3sat nano (includes interview with J. Anton Zensus)

April 10, 2019: Das erste Foto eines Schwarzen Lochs, Terra X Live, with Harald Lesch (MPIfR alumnus and member of Board of Trustees), including interview with J. Anton Zensus, Thomas P. Krichbaum, and Michael Kramer

French:

April 13, 2019: "Ses équations sont toujours conformes aux détections" : comment la première image d'un trou noir révèle tout le génie d'Albert Einstein, France TV Info, quoting Eduardo Ros

La publication d'une image de trou noir était encore inimaginable il y a quelques années. De nombreux chercheurs du projet Event Horizon Telescope ont salué leur père spirituel, un certain Albert Einstein, dont les travaux sont toujours d'actualité.

April 10, 2019: La première image d'un trou noir a été dévoilée, RTV Belge Francophone (includes interview with Eduardo Ros)

Spanish:

April 22, 2019: Primera imagen de un agujero negro, Canal Sur, Con Ciencia (min 01:30-11:45, including interviews with the MPIfR alumni Antxon Alberdi and Iván Martí Vidal, and with Eduardo Ros)

April 19, 2019: Cómo se logró captar la primera imagen de un agujero negro supermasivo, Interview with Eduardo Ros, Radio France Internationale

April 11, 2019: El agujero negro en M87, RTVE La Barra en 24h, Interview with MPIfR alumnus Iván Martí Vidal

April 11, 2019: La histórica primera imagen de un agujero negro: ¿Cómo la han captado los científicos?, Antena 3, quoting Eduardo Ros

April 10, 2019: Captan la primera fotografía real de un agujero negro, Noticias Chile T13 (includes interview with MPIfR alumna Violette Impellizzeri)

Twin, but asymmetric jets in the radio galaxy NGC 1052

26 February 2019

A study of twenty-nine observations using very-long-baseline interferometry in the radio galaxy NGC 1052, led by the MPIfR PhD student Anne-Kathrin Baczko, has revealed new details of the nature of the twin jet in this object.  Interestingly, the approaching (eastern) jet has higher kinetic energy, whereas the receding (western) jet has a larger internal energy or magnetic flux.  The inner structure of the jet can be explained by a spine-sheath with a fast inner layer and a slower outer layer.  These results are published in the present issue of the Astronomy & Astrophysics journal, for the original publication, see here. 

Resolving the innermost region of the radio galaxy NGC 1275 with mm-VLBI

19 February 2019

Using the Global mm-VLBI Array, an international team of astronomers led by J.Y. Kim from the MPI für Radioastronomie, has analysed the inner polarised structure of the nearby radio galaxy 3C 84 (NGC 1257), reaching resolutions of 50 μas (corresponding to ∼200 schwarzschild radii).  The results suggest that the emission is associated with an underlying limb-brightened jet.  The images match in resolution the ones obtained with space VLBI in our group, several months ago (see below).  These results are published in the present issue of the journal Astronomy & Astrophysics, for the original publication, see here.

Helical magnetic fields and a recollimation shock in the classical quasar CTA 102

CTA 102 monitoring with the Global millimetre-VLBI Array (GMVA), as presented in Casadio et al. A&amp;A 622, A158 (2019) (see their Figure 1).

12 February 2019

The popular radio source CTA 102 (see the song by the Californian band The Byrds from 1967) continues being the object of study of radio astronomers.  A new publication apppeared today, led by the MPIfR astronomer Carolina Casadio, reports on the magnetic field configuration and the interaction between traveling shocks and a recollimation shock in its relativistic jet.  The study is based on observations at the wavelengths of 3.5 mm and 7 mm performed in the mid 2010s.  A Faraday rotation analysis shows a gradient in the jet and intrinsic electric vector position angles oriented around the centroid of the innermost jet feature (core), suggesting the presence of large-scale helical magnetic fields.  Monitoring shows a feature moving superluminally and crossing the core (central, brightest) region. The polarisation orientation is different when the mentioned feature is exiting the core or crossing a stationary feature. The interaction between the superluminal component and a recollimation shock could have triggered the multi-wavelength flares. The variability Doppler factor associated with such an interaction is large enough to explain the high-energy emission and the remarkable optical flare occurred very close in time.  Further details on this work can be found at the original publication, see here. 

New Global Millimetre VLBI Array Survey released

01 February 2021

The new survey of the GMVA, led by Dhanya G. Nair at the MPI für Radioastronomie, has been released, simultaneously to the corresponding publication at the present issue of the Astronomy & Astrophysics journal.  The survey target source list has been compiled from the MOJAVE (Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments) sample, using the following selection criteria:

a) 15 GHz correlated flux density, Sc ≥ 0.5 Jy on baselines of ≥ 400 Mλ;
b) compactness at longest spacings, Sc /SVLBA ≥ 0.4 where S VLBA is the 15 GHz total clean flux density;
c) declination δ ≥ 15°.

With these selection criteria, a total of 162 unique sources have been selected, comprising 89 quasars, 26 BL Lac objects, 22 radio galaxies and 25 unidentified sources.  For further details, please visit the dedicated webpage.  Images can be downloaded here.

Lifting the veil on the black hole at the heart of our Galaxy

Lifting the veil on the black hole at the heart of our Galaxy

January 21, 2019
ALMA and the Global mm-VLBI Array team up and provide first scientific results more

Helical magnetic fields in the bent jet of the quasar OJ 287

November 12, 2018

A team of astronomers led by I. Myserlis at the MPIfR has analysed the variability of linear and circular polarisation of the quasar OJ 287 registered at the Effelsberg 100-m radio telescope and found that this emission is originated in the core region, where a helical magnetic field is twisted by a strong bending of the inner jet.  These results, based on intensive monitoring of the source, were possible thanks to a new, sophisticated polarimetric data analysis methodology which brings forward the capabilities of the Effelsberg telescope to unmatched precisions in any other radio telescope (presented here).  The helix arc length of the source is of 0.84 lt-yr and its radius smaller than 47 light days.  These results were published in the latest issue of the Astronomy & Astrophysics journal, see here.

Deep in the heart of M 87

September 12, 2018

The innermost jet in the nearby giant galaxy M 87, highlight image in the August issue of Astronomy &amp; Astrophysics.

A new publication led by MPIfR astronomers (see here) presents Global mm-VLBI Array (GMVA) observations at 3.5 mm wavelength of the nearby radio galaxy Messier 87, the central galaxy of the Virgo cluster in a distance of about 50 million light years. The highlight image shows the central region of M 87 at an angular resolution of ~50 μas (7 Schwarzschild radii).

The imaging reveals a parabolically expanding limb-brightened jet which emanates from a resolved VLBI core of about ten Schwarzschild radii in size. The observed brightness and compactness of the central feature suggests magnetic energy dominance at the jet base. Data yield an estimate the diameter of the jet at its base to be about five Schwarzschild radii assuming a self-similar jet structure. This suggests that the sheath of the jet may be anchored in the very inner portion of the accretion disk. Combined images reveal faint emission at the center of the edge-brightened jet on scales smaller than light years. 

Charge in the hole

August 12, 2018

Black holes have mass, angular momentum and potentially a charge. While the first two were measured routinely for some time now, constraining a black hole’s charge is more difficult.  A comment by Marios Karouzos in "Nature Astronomy" refers to an original paper by MPIfR authors led by Michal Zajaček in MNRAS, proposing an observational way to test limits on the charge of Sgr A*, the black hole at the centre of the Milky Way.  The original publication is available here.

The Rosetta stone of active galactic nuclei deciphered

The Rosetta stone of active galactic nuclei deciphered

June 21, 2018
A radio jet of a supermassive black hole has been investigated in so far unprecedented detail more
APEX takes a glimpse into the heart of darkness

APEX takes a glimpse into the heart of darkness

May 24, 2018
A global array of telescopes, including APEX, reveals the finest details so far on event horizon scales in the centre of our Galaxy more

Extreme outflows in radio-loud narrow-line Seyfert 1 galaxies

April 17, 2018

A team of astronomers led by Stefanie Komossa from the MPI für Radioastronomie in Bonn has studied four narrow-line Seyfert 1 galaxies and discovered extremely shifted spectral lines in their spectra, which indicate gas flying away from the central regions at speeds as high as 2450 km/s.  These galaxies are also emitteres in the radio part of the electromagnetic spectrum.  These results suggest that those galaxies are relatively young (in astronomical terms) with lifetimes of the order of magnitude of a million year.  The results are published in the present issue of the journal Monthly Notices of the Royal Astronomical Society, to be found here.

Can we tell black holes apart?

Can we tell black holes apart?

April 16, 2018
The current ability to test theories of gravity with black hole shadows more
Deep inside Perseus A

Deep inside Perseus A

April 03, 2018
A telescope larger than the Earth makes a sharp image of the formation of black hole jets in the core of a radio galaxy more

New images from the Southern radio sky

February 7, 2018

An international team of astronomers led by C. Müller (Radboud U. & MPI für Radioastronomie) has published new images from a sample of southern blazars in the framework of the TANAMI program.  These results are presented in the actual issue of Astronomy & Astrophysics.  A powerful array of Southern telescopes located in Australia, Antarctica, Chile, New Zealand, and South Africa was assembled to obtain these unprecedented images.  The TANAMI team found that that γ-ray loud sources tend to be more compact on parsec-scales and have higher brightness density in their central regions than γ-ray quiet sources.  More information can be found in the original publication here.

Synthetic images from remote galaxies: understanding obscured emission

January 12, 2018

Numerical simulations performed by a team of astronomers in Frankfurt, Bonn, and Valencia led by C.M. Fromm have managed to synthesize the emission from radio objects with an obscuring torus.  The numerical code Ratpenat was used to model several jets embedded in various ambient medium and torus configurations and subsequently computed their images, including jet emission and torus absorption.  These simulations help understanding the physics of jets and tori, and suggets observational methods such as the core-shift to discern between different physical scenarios in the jet (e.g., if they have equal pressure inside and outside the jet, or if the pressure outside is larger).  These results are shown in the present issue of the journal Astronomy & Astrophysics, for more details see here. 

And it burns, burns, burns... the ring of fire and orphan gamma-ray flares

20 November 2017

A team of radio astronomers led by Nicholas MacDonald, affiliated to the MPI für Radioastronomie and Boston University, has developed the ring of fire model to explain the origin of γ-ray flares in blazars without correspondence in the radio band.  A ring of shocked plasma along the relativistic outflows in blazars can explain the missing emission in the radio observed in a sample of blazars, the most prominent sources in the non-thermal sky (that is, with radiation of non-thermal origin, both in the radio and the γ bands.   Further details of this work, connecting theory and observations, can be obtained in the original publication in the Astrophysical Journal here. 

Blazar 3C 273 probed at the highest resolution with space-VLBI

22 August 2017

The RadioAstron space mission continues providing sharp images from the most compact objects in the radio sky. Observations led by Gabriele Bruni at the MPI für Radioastronomie of the radio source 3C 273 in the framework of the Polarisation Key Science Projet of RadioAstron are reported in the present issue of the journal Astronomy & Astrophysics.  The results reveal that the nuclear brightness temperature of thte source is hundred times larger than the exceptional value detected in earlier observations in 2013.  New features are also present in the jet.  Further details can be found at the original publication here.

Measuring the masses of young stars, a puzzle for stellar models

June 12, 2017

An international team of astronomers led by Bonn researcher Rebecca Azulay reports in the present issue of Astronomy and Astrophysics results from astrometric measurements of the pre-main-sequence stars HD 160934 A and C, EK Dra, LO Peg, and PW And.  The results present observational evidence that the stellar evolutionary models underpredict the mass of those stars by 10%-40%, challenging the present approach for modeling.  The authors suggest that the magnetic activity of stellar coronae triggers gyrosynchrotron emission from non-thermal, accelerated electrons.  Detailed information can be found in the original publication here.

Misaligned Active Galactic Nuclei, paving the way to the Cherenkov Telescope Array

May 12, 2017

Radio loud Active Galactic Nuclei (AGN) with the jet not pointing directly to the observer are a new class of GeV emitters revealed by the Fermi-LAT space telescope.  A team of astronomers led by the MPIfR PhD researcher Roberto Angioni publishes in the present issue of Astroparticle Physics a study of the impact of the Cherenkov Telescope Array (CTA) on the misaligned AGN class and proposes observational strategies to optimise their detection.  More information, directly in the original publication here.

Deep inside Galaxy M87

Deep inside Galaxy M87

April 20, 2017
The origin of the jet from the close vicinity of the central black hole of an active galaxy more

Millimetre Eyes to the Black Hole Universe

March 30, 2017

Cutting-edge observations aim to directly image the immediate environment of a black hole on the first two weeks of April 2017 by two arrays of telescopes including the highly-sensitive Atacama Large Millimetre Array.  The „Event Horizon Telescope”(EHT) is an international project which will allow to test Einstein’s Theory of General Relativity in an extreme regime. The Global Millimetre VLBI Array, managed by the Max Planck Institute for Radio Astronomy, will complement these observations. A number of European research institutes participate in the observations, to be partially post-processed at the correlator center in Bonn.

The GMVA network will perform observations with 14 antennas from March 31 to April 4, focusing on several active galaxies, among those 3 targets will be observed jointly with the ALMA telescope in Chile.  The 100-m radio telescope in Effelsberg will participate in the GMVA observations.  For the EHT observations, see the MPIfR and the MPG press releases here and here, respectively.

The analysis of the GMVA observations including phased ALMA will be completely postprocessed at the MPIfR correlator in Bonn.  

MPIfR scientists traveling for the mm-VLBI observations in April 2017.  From left to right: R. Azulay (Pico Veleta), S. Dornbusch (APEX), H. Rottmann (Pico Veleta &amp; ALMA), A.L. Roy (APEX), and Thomas P. Krichbaum (Pico Veleta).

Following sources will be observed with joint observations from the GMVA and ALMA: Sgr A* (PI Brinkerink, Radboud Univ. Nijmegen), 3C 273 (PI Akiyama, MIT & National Astronomical Observatory of Japan (NAOJ)), and OJ 287 (PI Gómez, Instituto de Astrofísica de Andalucía).  Additionally, GMVA-only observations will be performed from March 30 to April 2, for following sources: M 87 (PI Asada, ASIAA), NGC 1052 (PI Baczko, MPIfR), NGC 1275 (PI Nagai, NAOJ), and gamma-loud blazars (PI Marscher, Boston University).  The block schedule for the Spring 2017 session is shown here.

A team of MPIfR astronomers is traveling to the telescopes for supporting and performing the observations, namely, Rebecca Azulay (Pico Veleta), Sven Dornbusch (APEX), Thomas P. Krichbaum (Pico Veleta), Helge Rottmann (Pico Veleta and ALMA), and Alan Roy (APEX).  An extended team is traveling for the GMVA observations to the house telescope, the 100-m dish in Effelsberg 40 km away from Bonn, coordinated by Thomas Krichbaum before he leaves to Pico Veleta: Walter Alef, Roberto Angioni, Uwe Bach, Jae-Young Kim, Cornelia Müller (Radboud Univ. Nijmegen), Eduardo Ros, Efthalia Traianou, and Laura Vega García.  

Can millimetre-wavelength interferometry observations challenge the existence of black holes?

March 2, 2017

Andrei Lobanov, staff scientist at the MPIfR discuss in the present issue of Nature Astronomy the existence of black holes and an observational test for those, based on the study of the magnetic fields in the central regions of super massive objects.   The Event Horizon Telescope has the capability to observe the polarised emission in the neighbourhood of the putative event horizon, and magnetic field values beyond 104 Gauss may challenge the standard interpretation of the physics in these objects.  More information in the original publication here.

Radio astronomers score high marks in the competition for EU funding

Radio astronomers score high marks in the competition for EU funding

January 11, 2017
10 million Euro for European consortium under the leadership of the German Max Planck Institute for Radio Astronomy more

The origin of the γ-ray emission in the 'wobbling' jet in the blazar OJ 287

January 6, 2017

MPIfR astronomers led by J. Hodgson have identified the location of the high-energy emission in the BL Lac object OJ 287, known by its periodic flux density outbursts and its wobbling parsec-scale jet.  These findings are based in the comparison of very detailed images obtained with the Global Millimetre VLBI Array with the γ-ray light curves from the Fermi space telescope.  The international team could estimate the strength of the magnetic field, larger than 1.6 Gauss in the central region and below 0.4 Gauss in the relativistic stream.  This study has been published in the present issue of the Astronomy & Astrophysics journal, see here.

Data for 2.5 years from the Effelsberg Key Science Project F-GAMMA released 

28 November 2016

The present issue of the journal Astronomy & Astrophysics reports the light curves and spectra of a sample of about 60 sources observed with the Radio Telescope Effelsberg (together with the IRAM 30 m telescope at Pico Veleta).  This unprecedented data base reveals that all observed gamma-loud radio galaxies are variable accross all frequencies with variability increasing at the higher ones.  Interestingly, radio flux at wavelengths of 3.5 mm and 2.0 mm correlate with gamma-ray fluxes. The F-GAMMA project is one of the most relevant radio astronomical projects at present, connecting the radio emission of blazars with their high-energy properties.  More information is available at the original publication, led by the MPIfR astronomer L. Fuhrmann, here.

The puzzling Narrow-Line Seyfert Galaxy 1H 0323+342, observed at the highest resolution in the radio regime

1 November 2016

A team of astronomers led by L. Fuhrmann from the MPIfR has observed the radio galaxy 1H 0323+342 with an armada of telescopes including the Effelsberg 100-m and IRAM 30-m telescopes, in the course of the F-GAMMA program.  The observations reveal superluminal motions with apparent speeds up to seven times the light speed.  Those allowed the international team to estimate the viewing angle of the relativistic flow, to be smaller than 9º. These findings have been published in the present issue of the journal Research in Astronomy and Astrophysics.  More information can be found at the original publication here.

The quasar 3C 273 and its γ-ray flares: results from a multi-band campaign

September 27, 2016

Total intensity and polarization observations of the quasar 3C 273 were carried out between 2013 December 28 and 2014 January 03 using the Fermi-Large Area Telescope, Swift-XRT, Swift-UVOT, and Korean VLBI Network telescopes.  No relationship was found with the radio total intensity and polarised emission.  However, the coincidence of the increase in radio polarization with the X-ray flux supports the picture that X-rays are produced via inverse-Compton scattering of radio photons. Correlation was found between a flare in the optical/near-UV passbands and a concurrent γ-ray flare These results are presented in the last issue of the journal Monthly Notices of the Royal Astronomical Society, see here.

Twin jets pinpoint the heart of an active galaxy

Twin jets pinpoint the heart of an active galaxy

September 12, 2016
Magnetism dominates environment of the central black hole more

A battery of mathematical tools to attack the emission mechanisms in a remote blazar

May 11, 2016

A study based on the Master Thesis of Ms. Céline Chidiac and published in the present issue of Astronomy & Astrophysics shows the nature of the variability in the quasar 3C 279. This remote blazar shows violent variations in brightness through the electromagnetic spectrum.  The relationship between the light curves at different bands (radio, X, and γ rays) has been studied by the power spectral density.  Results show a delay between the variations at γ and radio waves, where the former lead, suggesting that the high-energy emission originates at a region 4 lt-yr inside the jet apex.  A delay is also observed from the γ to the X rays.  More details on the study are provided in the original publication here.

The location of the γ rays in the blazar PKS 1502+106

May 10, 2016

A team of MPIfR astronomers led by V. Karamanavis has addressed the location of the high-energy emission i the blazar PKS 1502+106 from multi-band studies of a radio flare.  Single-dish observations were carried out at 12 frequencies in the range 2.5 to 227 GHz.  The γ-ray active region is located 6.2 lt-yr away from the jet base of the source.  The data used in this work have been collected within the framework of the Fermi-GST AGN Multi-frequency Monitoring Alliance (F-GAMMA) program.  The results are published in the present issue of the journal Astronomy and Astrophysics.  The original publication is available here.

The radio and γ-ray properties of the TANAMI sources

May 4, 2016

The TANAMI program observes parsec-scale radio jets of southern γ-ray bright active galactic nuclei simultaneously with Fermi/LAT monitoring of their γ-ray emission, via VLBI observations.  A study published this week in Astronomy & Astrophysics and led by the MPIfR astronomer Moritz Böck shows that a 72% of these blazars can be associated with bright γ sources.  The association differs from the optical class of sources, being 76% for quasars and 17% for galaxies.  The birghtness temperatures of the radio cores increase with the γ-ray luinosity.  The results show as well that there is a direct relationship between the γ-ray and the radio luminosities.  More information about this study is available here.

Possible Extragalactic Source of High-Energy Neutrinos

Possible Extragalactic Source of High-Energy Neutrinos

April 28, 2016
Coincidence of a highly energetic outburst of an active galactic nucleus with a neutrino event at PeV energy more

Magnetic field swings in the blazar 3C 279

April 28, 2016

A study of the polarised emission of thequasar 3C 279 led by the MPIfR astronomer Dr. Sebastian Kiehlmann reports in the present issue of the journal Astronomy and Astronomy about the changes in the field over the past few years.  Data from optical polarimetry were combined and the location of the electric vector position angle of the linearly polarized emission were studied in detail.  The most spectacular changes occurred in mid 2011 with a 360º rotation.  The large team of astronomers conclude that during two different optical flxu states, two different processes govern the changes in polarisation, which has a stochastic nature during the low-brightness state and a deterministic nature during the flaring activity.  More information is available here.

First 3 mm-VLBI imaging of the two-sided jet in Cygnus A

March 31, 2016
For the first time, VLBI images have been obtained of the archetypal radio galaxy Cygnus A at the frequency of 86 GHz. The high spatial resolution gives insight into the transverse width profile at the onset of the two-sided flow. The publication from an MPIfR research team led by Biagina Boccardi appears as highlight in the present issue of the research journal "Astronomy & Astrophysics" more

Numerical simulations provide clue on the physics of flaring blazars

March 24, 2016

A team led by Christian M. Fromm from the VLBI group of the MPIfR has reported results of relativistic hydrodynamic simulations of jets.  The goal was to investigate the evolution of the brightness of their source and the polychromatic properties in radio wavelenghts assuming the interaction of a traveling shock wave with a steady (recollimation) shock wave in the relativistic outflow of blazars.  The results, published today in Astronomy and Astrophysics, reveal that the injection of porturbations in a jet have a signature in the emission of the source at centimetre wavelengths previously to the main flare.  This is observed both in single-dish and in long-baseline interferometric observations.  These results help interpreting early findings on the blazar CTA 102 during a major outburst in the mid 2000s. 

More information can be found in the original publication here.

To the center of the brightest quasar

To the center of the brightest quasar

March 29, 2016
RadioAstron observations of the extremely hot heart of quasar 3C 273 more
Smoking Gun Uncovering Secret of Cosmic Bullets

Smoking Gun Uncovering Secret of Cosmic Bullets

March 02, 2016
LOFAR radio telescope catches signals from disintegrating cosmic particles, revealing their nature more

A 'wise' method to study radio images and detect different speed patterns

February 12, 2016

Florent Mertens and Andrei Lobanov from the MPI für Radio Astronomy have proven multiple velocity components in partially overlapping emitting regions in radio images at parsec-scales.  3C&nbsp;120, 3C&nbsp;120, and M&nbsp;87 images were addressed by the 'wavelet-based image segmenttion and evaluation' (WISE) technique of decomposition of two-dimensional structures.  The method demonstrates the robust detection of a faster spine and a slower sheath speed in an extragalactic, relativistic outflow.  This approach has potential application beyond the field of radio imaging. 

More information is available at the original publication here.

A puzzling feature off-stream in the high-energy blazar Mrk 501

February 2, 2016

An international team led by Shoko Koyama from the MPI für Radio Astronomy has discovered an off-axis jet feature in the source Mrk 501.  Her team used millimetre-wavelength very-long-baseline interferometry to probe the sub-parsec scales of the innermost regions of this region.  All images show a new feature in the northeast direction, whereas the source shows a southward relativistic outflow in all earlier images.  Her studies show spectral information between the 7mm and 3mm wavelengths as well.

Additional information on these findings can be found here.

Improving the images of the black hole at the centre of our Galaxy: mitigation of source variability

February 1st, 2016

A study led by the MPIfR astronomer RuSen Lu reports in the present issue of The Astrophysical Journal results on the mitigation of the brightness variability effect in the studies of the source.  The ultimate goal of VLBI observations of this source and the nearby galaxy M 87 is to image the immediate neighbourhood of the central super-massive black hole at event horizon scales.  The work presented by Lu shows methods to prevent degradation of the image of this source by source vriability, as predicted by general relativistic magnetohydrodynamic simulations.  Additionally, interstellar scattering degrades the imaging process as well.  These techniques will be applied to the source study for future Event Horizon Telescope (EHT) observations.  More information can be found here.

A blazar at extreme angular resolution: PKS 1502+106

January 26, 2016

A study led by MPIfR astronomer V. Karamanavis, published this week in the journal Astronomy & Astrophysics, shows the compact morphology and superluminal motions of the blazar PKS 1502+106.  This object was discovered by the Fermi/LAT satellite in gamma rays and shows a rapid variability.  The source was studied in a multi-wavelength campaign, including also single-dish data from Effelsberg and other antennas in the F-GAMMA project.  The values measured for the superluminal motions in the source range from 5 to 22 times the speed of light, suggesting a very small viewing angle to the source jet.   More information can be found in the original publication here.

BL Lacertae - the hottest cosmic hearth

BL Lacertae - the hottest cosmic hearth

January 25, 2016
Radio astronomers look deep inside a galactic nucleus more

Unveiling Gargantua: searching central cluster black holes

January 14, 2016

More information can be found in the original publication here.

Cygnus A: a powerful galaxy with a stratified, two-side jet

December 11, 2015

A study led by the Bonn astronomer Bia Boccardi shows results from imaging at high resolution of the double jet in the heart of the galaxy Cygnus A.  This nearby object, at a distance of 249 Mpc, allows astronomers to probe regions of only 400 Schwarzschild radii from the central, powerful super massive black hole.  The new study, based partially on the PhD Thesis of Boccardi, shows a stratified structure in the jet of this source, with a fast and a slow layer with different acceleration gradients in the relativistic outflows from the source.  More information can be found in the original publication here.

Deep into the Center of the Milky Way

Deep into the Center of the Milky Way

December 03, 2015
Event Horizon Telescope Reveals Magnetic Fields at the Central Black Hole of our Galaxy more

Far, far away: space VLBI observations of magnetic fields in the high-redshift quasar 0642+449

November 2, 2015

More information can be found in the original publication here. 

Pioneering observations at the highest VLBI frequency in the southern Hemisphere: 3C 279 and APEX

August 27, 2015

More information can be found in the original publication here.

Radio light curves in blazars deciphered

August 7, 2015

A team of astronomers led by Christian M. Fromm at the MPI für Radioastronomie has modeled the mechanisms of emission in radio light curves from a thoeretical study of the peaks in brightness and wavelength in the radio spectra (the so-called turnover frequency-turnover flux density plane).  For this, they applied the shock-in-jet scenario, commonly used to explain the spectral behaviour of active galactic nuclei.  These results are shown in detail in the lastest issue of Astronomy and Astrophysics, see here.

Giant radio flare in a micro quasar

July 21, 2015

The micro quasar LS I +61°303 was studied during radio outbursts by the radio telescope Effelsberg.  These observations, performed at several frequency bands, and led by the MPIfR PhD student Lisa Zimmermann, with the collaboration of the Bonn astronomers Lars Fuhrmann and Maria Massi, reveals a flat spectral index (that is, the same brightness at different wavelengths), with superimposed sub-flares with higher flux densities at lower wavelengths.  These characteristics resemble the microquasars XTE J1752-223 and Cygnus X-3.  These results have been presented at the last issue of the European journal Astronomy and Astrophysics.  For more information, see here.  

The galaxy NGC 3718 observed with radio and infrared telescopes

July 20, 2015

A team led by the astronomer K. Markakis from the MPI für Radioastronomie and the University of Cologne has observed the low-ionisation nuclear emission-line region L1.9 galaxy NGC 3718 at 56 million light years with the Subaru telescope at the infrared and the e-MERLIN telescope in the radio regime.  These observations show the existence of a supermassive black hole recoil.  The journal Astronomy and Astrophysics publishes theses results in the latest issue.  More information can be found here.

Diagram showing the change in position of the radio core of source Markarian 451 as observed by VLBI after a major radio flare.

Discovery of the wandering base of a radio jet after a major X-ray flare

July 1, 2015

Based on VLBI observations of the radio source, Markarian 421, a team including Shoko Koyama from the MPI für Radioastronomie, led by Kotaro Niinuma (Yamaguchi University) has discovered have discovered a new phenomenon in which the position of a radio jet base, a type of object which had been thought to be stationary, "wanders" widely along the jet axis. Radio jets ejected from the vicinity of super-massive black holes lurking at the center of active galaxies have been being observed for many years, but the team shows the first time anyone in the world has directly detected this "wandering phenomenon" of the radio jet base. These results were published in the latest issue of the Astrophysical Journal Letters, see here.  Additional information, in the press release of Yamaguchi University, in English and in Japanese, as well as in the National Astronomical Observatory of Japan in Japanese.

Connecting brightness variability and motions in the jet of a blazar

June 15, 2015

A team of astronomers from the MPI für Radioastronomie led by Bindu Rani has found a connection between a flux disturbance in the base of the jet in the radio source S5 0716+714 and optical--to--gamma-ray variations upstream of the central feature in the jet of the source at parsec scales.  The relativistic doppler factors, however, are different for the gamma and the radio emission.  The radio images show a decline of the measured brightness temperature in the jet with distance with a power index of -2.36.  These results have been published in the latest issue of the journal Astronomy and Astrophysics.  For more information, see here.

How heavy are the stars in the southern AB Doradus system?

May 25, 2015

Astrometrical observations of the double star AB Doradus B in the complex system AB doradus have revealed the exact, dynamical masses of both stars.  The Ba star has a weight of 28 solar masses, whereas AB Doradus weighs 0.25 solar masses.  Those measurements contradict the predictions by evolutionary models, which should be revised.  Models overestimate those masses.  The results of this work, performed with the Australian Long Baseline Array and led by the PhD student Rebecca Azulay from the MPI für Radioastronomie and the University of Valencia, have been published this week in the scientific journal Astronomy & Astrophysics, see here.

Observations of weak blazars with the European VLBI Network

April 28, 2015

A team of astronomers led by Franco Mantovani from the Bonn MPI für Radioastronomie has studied a sample of radio weak blazars with the European VLBI Network.  This sample was selected from a group of X-ray emitting galaxies.  All observed 87 sources were detected, 39 of those are point-like at VLBI scales, and 48 show a jet structure.  56 of these sources can be considered blazars.  The results of this work have been published this week at the journal Astronomy & Astrophysics, see here.

A Sharp View into Black Holes

A Sharp View into Black Holes

April 21, 2015
Planet-Sized Telescope Connects Chile and the South Pole more

Where is located the black hole in the galaxy CTA 102?

March 25, 2015

A team of astronomers led by the Bonn scientist Christian Fromm (MPI für Radioastronomie) has measured the position of the supermassive black hole at the centre of the galaxy CTA 102.  This black hole is as heavy as several billion times our Sun.  This object was already notorious in the 1960s as a candidate for hosting aliens, given its regular radio emission.  Nowadays we know it is a powerful, remote quasar.  The black hole is located at several ten thousand gravitational radii from the brightest radio point in astronomical images.  These results have been published in the latest issue of the journal Astronomy & Astrophysics.  An onlne version of the publication can be found  here.

A Missing Link in the Family Tree of Cosmic Black Holes

A Missing Link in the Family Tree of Cosmic Black Holes

March 05, 2015
Intermediate-mass black hole with a powerful jet more

Gamma-loud narrow-line Seyfert 1 galaxies studied in the radio

February 23, 2015

A international team led by Dr. Emmanouil Angelakis from the MPI for Radio Astronomy in Bonn has studied the radio jet emission from a puzzling class of active galactic nuclei: the narrow-line Seyfert 1 galaxies emitting gamma rays at the GeV range of energies.  They studied four objects which were detected by the space gamma-ray satellite Fermi and in the radio, discovered in the early 2010s.   As of today, seven of these objects have been discovered.  The four studied sources show the typical characteristics of blazars such as intensive variability, spectral evolution corresponding to traveling plasma shocks, and Doppler factors indicating mildly relativistic speeds in the jet. This work has been published in the last issue of the international journal Astronomy & Astrophysics. [more]

Radiation from the heart of the powerful quasar RX J2314.9+2243

February 4, 2015

An international team lead by S. Komossa from the MPI for Radio Astronomy, has observed the quasar RX J2314.9+2243 in the optical, ultra-violet, X-rays, and radio bands.  A fifth of all active galaxies is radio loud.  A new class of these objects was discovered in the last years, the narrow-line Seyfert 1 galaxies.  Those objects have extreme emission properties.  One of them, with a high radio loudness, has been observed systematically by the Bonn team.  The results show an energy distribution originated by electrons under the influence of strong magnetic fields (synchrotron radioation).  This quasar shows as well a powerful outflow in the optical part of the spectrum.  The results of this work have been published in the latest issue of Astronomy & Astrophysics. [more]

How compact and bright can be a source in the sky?

January 30, 2015

The answer of this question can be better answered after the last development published in the last issue of Astronomy & Astrophysics by Andrei P. Lobanov from the MPI for Radio Astronomy.  The physical properties of compact sources can be characterised by the brightness temperature.  The new method presented by Lobanov, which allows us to compute the brightness temperature limits from interferometric measurements, has been successfully tested with data from the MOJAVE project and from mm-VLBI observations.  Its application to space VLBI obsrvations promises new limits in the brightness temperature of compact, remote objects, for future observations. [more]

A new method to analyse astronomical images

January 27, 2015

A new, automatic method for astronomical image analysis has been developed by the graduate student Florent Mertens and his supervisor, Andrei Lobanov, both at the MPI for Radio Astronomy.  This mehtod is based on wavelet functions to determine distinct regions in astronomical images and to study their evolution, following the wavelet-based image segmentation and evaluation (WISE) approach.  This was successfully tested in the sources 3C 273 and 3C 120.  The two-dimensional evolution of the features of the jets in both sources was studied, and it is compatible with the effect of Kelvin-Helmholtz instabilities.  This work was published in the last issue of the journal Astronomy & Astrophysics [more]

Galaxy evolution studied with the 100-m telescope in Effelsberg

December 23, 2014

A study lead by MPIfR astronomer Mariangela Vitale has probed the importance of active galactic nuclei (AGN) in galaxy evolution.  Models need AGN feedback to explain the observed luminosity in galaxies.   The team studied a sample of radio emitters at distances between 580 Mio lt-yr and 7150 Mio lt-yr, to search for spectral evolution and al ink between optical and radio emission.  Some hints of spectral index flattening in high-metallicity star-forming galaxies, composite galaxies, and Seyferts have been found.  Therefore, galaxies along the sequence are transitioning from the active star-forming calaxies (blue cloud) to the passive elliptical galaxies (red sequence).  This supports the suggestion that AGN shut down star formation and allow transition from one galaxy class to the other.   These results have been published in the last issue of the journal Astronomy & Astrophysics, see the original publication here.

Galaxy in false colours: The chart shows IC 310 in the gamma ray range. The inset zooms into the centre of the galaxy and shows details of the jet, taken in the radiowave range by the European VLBI Network. The contour lines describe the jet’s structure, which starts near the black hole at the heart of IC310.

Lightning flashes from a black hole - MAGIC telescopes observe an extremely short, powerful outburst of radiation in Galaxy IC 310

06 November 2014

The radio galaxy IC 310 in the Perseus constellation is approximately 260 million light years away from Earth. Astronomers assume there is a supermassive black hole at its centre. This black hole was the setting for an extremely powerful outburst of gamma rays which was observed by the MAGIC telescopes on La Palma in the Canary Islands. The source exhibited one of the fastest radiation variations which researchers have ever been able to detect in an extragalactic object at these energies.  Ancillary observations from the European VLBI Network reveal a powerful radio jet.  Uwe Bach and Eduardo Ros from the MPI für Radioastronomie are co-authors of this work, published in today's issue of the journal Science.  [more]

Media Impact: IFLScience, Universe Today, Science Daily, SpaceRef, MSN (Spanish)

Discovery of a correlation between gamma-ray emission and jet position angle in a blazar

06 November 2014

A team of researchers led by Bindu Rani from the VLBI department of the MPI für Radioastronomie reports for the first time the correlation between gamma-ray emission and the position angle of a jet in a blazar, namely, in the object S5 0716+714.  This implies that the inner jet morphology of AGN jets has a direct connection to the emission of gamma-ray flares.  The observations of this BL Lac objects were carried between August 2008 and September 2013.  The mm-VLBI core radio brightness variations are delayed with respect to the γ-ray flux by 82±32 days.  These results are published in the last issue of the journal Astronomy & Astrophysics, and are part of the successful PhD work of Bindu Rani, presently a postdoctoral fellow at the MPIfR. [more]

The central engine of broad-absorption-line quasars has the same properties for sources with or without a jet

29 September 2014

A study led by Gabriele Bruni from the MPI für Radioastronomie has focused in the study of two samples of broad-absorption-line quasars, aiming for explaining the reasons for the rarity of the radio-loud ones.  The study, carried out with the Telescopio Nazionale Galileo, could show that both classes of objects have the same black-hole mass, the broad-line region radius, and Eddington ratio.  These results are presented in the last issue of Astronomy & Astrophysics. [more]

Type Ia supernovae stem from the explosion of white dwarfs coupled with twin stars

August 20, 2014

Study discards possibility that type Ia supernovae might stem from explosions of white dwarfs nourished by normal stars. Were these conclusions to become generalized, type Ia supernovae might no longer serve as “standard candles” to measure astronomical distances.  This work, using the European VLBI Network and the 100-m radio telescope in Effelsberg, was done in collaboration with the MPIfR VLBI Department. [more]
Powerful magnetic fields challenge black holes' pull

Powerful magnetic fields challenge black holes' pull

June 04, 2014
Magnetic forces in the environment of Active Galactic Nuclei can match gravitational forces more
Violent gamma-ray outbursts near supermassive black holes

Violent gamma-ray outbursts near supermassive black holes

May 22, 2014
Joint radio and gamma-ray observations allow outbursts in the nuclear regions of active galaxies to be localized more

An armada of telescopes decipher the emission of the powerful galaxy GB 1310+487

April 28, 2014

An international team of astronomers led by K. Sokolovsky and F. Schinzel at the MPIfR has deciphered the broadband emission of the narrow-line gamma-ray-loud AGN GB 1310+487.  Observations include data from the Fermi, AGILE and Swift space telescopes at high frequencies and from the Kanata, NOT, Keck, OAGH, WISE, IRAM 30-m, OVRO 40-m, Effelsberg 100-m, RATAN-600 and the VLBA in the optical-infrared-radio area.  Fermi/LAT observations reveal a strong correlation between the gamma-ray flux and spectral index, being harder at the brighter flux.  The gamma flares occurred before and during a slow rising trend of the radio eission, but no direct association between gamma and radio flares could be stablishesd.  The results are published in Astronomy & Astrophysics.  [more]

A Dance of Black Holes

A Dance of Black Holes

April 22, 2014
Unique pair of supermassive black holes in an ordinary galaxy discovered by XMM-Newton more

Merging galaxies and the size of their cores

February 26, 2014

A study of a sample of 52 double nucleus disk galaxies, led by M. Mezcua and A.P. Lobanov from the MPIfR, derived the luminosity of each of the nuclei and their relative separation from a multi-component photometric fit of the galaxies in the Sloan Digital Sky Survey optical images.  The nuclei in moft of the sources have projected separations smaller than 10000 light-years.  A sample of 19 double nucleus disk galaxies have separations smaller than 3000 light-years and are candidates to be binary active galactic nuclei. [more]

Discovery of four new magmasers in Seyfert 2 and OH maser/absorber galaxies

November 28, 2013

A study performed by J. Wagner, PhD student at the MPIfR VLBI department, has discovered four water megamasers in a sample of 37 galaxies.  The sample of galaxies were selected by high X-ray luminosity and high absorbing column densities.  The sources included dual or triple AGN and interacting systems.  These results are presented in the present issue of Astronomy & Astrophysics. [more]

An ordered, helical magnetic near the central black hole in the quasar 3C 454.3

October 28, 2013

Astronomers from the MPIfR VLBI department presented evidence that the radio emission from the jet of the quasar 3C 454.3 exhibits multiple signatures of a large-scale, ordered helical magnetic field component at a distance of hundreds of parsecs from the launching point. These results provide observational support for magnetic jet launching models and indicate that the ordered helical field component may remain stable over a large distance down the jet.  This was predicted for the models for the central engine, but so far it was unclear if this order was preserved further down in the jet.  [more]

Causal connection in parsec-scale relativistic jets found from MOJAVE observations

October 23, 2013

Astronomers from the MPIfR led by E. Clausen-Brown have found a causal connection in active galactic nucleus jets, based on observations from a sample of 133 objects.  This is shown by the value of a parameter Γθj, the product of the jet Lorentz factor and the intrinsic opening angle.  If this value is smaller or equals 1, there is a causal connection between the jet edges and its symmetry axis.  The details of a novel study are presented in the last issue of the Astronomy & Astrophysics journal.  [more]

Image of the mysterious supernova remnant SNR 4449-1 in the galaxy NGC 4449

October 4, 2013

A team of astronomers of the MPIfR VLBI department has imaged the milliarsecond-scale radio structure of a nearby supernova remnant at a wavelength of 18 cm with the European VLBI Network.  The observations confirm earlier identifications of this object.  More details can be found in the original publication, published in the Monthly Notices of the Royal Astronomical Society.  [more]

Jet emission in intermediate-mass black holes?

October 3, 2013

An international team of astronomers led by M. Mezcua from the MPIfR has presented evidence of compact radio emission in the ultraluminous X-ra source N5457-X9 within the X-ray error position, making this a potential intermediate-mass black hole steady jet emission.  These results, together with VLBI observations of N4559-X4, are presented in the journal Monthly Notices of the Royal Astronomical Society.  [more]

The quasar and its Fata Morgana

The quasar and its Fata Morgana

September 05, 2013
Multiple images of a quasar through a gas cloud of our Milky Way more
Measuring the universe’s ‘exit door’ - For the first time, an international team has measured the radius of a black hole.

September 27, 2012

Press Release of the Massachussetts Institute of Technology (MIT) on VLBI observations of the innermost region of M87 in the Virgo Cluster at a wavelength of 1.3 cm. Thomas Krichbaum from the MPIfR is Co-Author of the original paper published in "Science": Jet-Launching Structure Resolved Near the Supermassive Black Hole in M87 (Sciencexpress dated 27 September 2012, 10.1126/science.1224768). This work is part of the MPIfR's efforts to enable global VLBI observations at 1 mm wavelength. [more]
A magnification of two million

A magnification of two million

July 18, 2012
Telescope network zooms in on the heart of a distant quasar more
Close-up of active galactic nucleus

Close-up of active galactic nucleus

July 06, 2012
First interferometric signals between the Effelsberg telescope and orbital radio telescope Spektr-R more
A Boost for European Radio Astronomy

A Boost for European Radio Astronomy

January 05, 2012
27 Partner Organizations with World-class Instruments work together in Observations, Research & Development more
The birth of a telescope 30 times larger than Earth

The birth of a telescope 30 times larger than Earth

December 08, 2011
First interferometric signals detected between the Effelsberg 100-meter telescope and the space-borne antenna Spektr-R of the RadioAstron project more
The Mightiest Monsters of the Universe

The Mightiest Monsters of the Universe

April 22, 2009
Brightest ultrafast jets in active galaxies found to be powerful gamma-ray beacons more
Water in the early Universe

Water in the early Universe

December 18, 2008
Detection of H2O at record distance with the Effelsberg 100 m radio telescope more
Effelsberg telescope included in a world-wide network

Effelsberg telescope included in a world-wide network

November 21, 2008
Largest European radio telescope inaugurated as member of e-VLBI more
Zooming in on the Super-massive Black Hole in the Center of the Milky Way

Zooming in on the Super-massive Black Hole in the Center of the Milky Way

September 03, 2008
The Closest View of the Central Source of our Galaxy more
The largest synthesized telescope in Europe doubles its surface

The largest synthesized telescope in Europe doubles its surface

April 09, 2008
Inclusion of the Effelsberg 100m Telescope to the fastest connected radio telescope in the World more
Strengthening the German-Australian Connection in Radio Astronomy

Strengthening the German-Australian Connection in Radio Astronomy

March 05, 2008
Scientific cooperation agreement signed more
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