Research Contributions to the Yearbook of the Max Planck Society
(Full contributions are in German)
Testing Einstein's Most Fortunate Thought
Extremely precise measurements of the motion of a fast-spinning pulsar in a triple star system provide one of the strongest tests ever of a simple, but fundamental prediction of general relativity: that gravity affects all objects with the same acceleration, without regard for their composition, density or the strength of their own gravitational field. General relativity has again survived this test, one of the most stringent ever, which strongly constrains many alternative theories of gravity.
The first image of the shadow of a black hole
Zensus, J. Anton; Kramer, Michael; Menten, Karl M.; Britzen, Silke (2019)
On April 10, 2019, the first image of a black hole was published by a team of 347 international scientists from 59 institutes in 18 countries. Theoretical work and indirect evidence for the existence of black holes has been around for a long time. Only now did the observations provide the necessary resolution for an image made possible by a combination of seven radio telescopes scattered across the Earth, observing the centre of the galaxy M87. More than 30 scientists and engineers of the Max Planck Institute for Radio Astronomy in Bonn are involved in this success.
The airborne observatory SOFIA reveals gas kinematics in the Lagoon nebula
Wyrowski, F.; Wiesemeyer, H.; Tiwari, M.; Klein, B.; Menten, K.M. (2018)
The airborne observatory SOFIA allows astronomical observations in the Far-Infrared, which is not accessible from the ground. It covers the most important cooling lines of the interstellar medium. Velocity-resolved observations of these lines are crucial for our understanding of the star formation process. Here we present observations of the ionized carbon finestructure line in the Lagoon Nebula, which for the first time reveals the gas motions in the immediate environment of the nebula.
Zooming into the heart of a radio galaxy
The formation of relativistic jets in active galaxies is a poorly understood physical process. Providing observational constraints for theoretical models is a crucial but challenging task, since it requires the imaging of emission regions in the immediate proximity of the black hole. We have observed the prototype radio galaxy Cygnus A through very-long-baseline interferometry at millimeter wavelengths, and obtained a sharp view of the jet base. Our analysis of the jet kinematic properties and internal structure suggests that the jet of Cygnus A is a disk wind accelerated by magnetic fields.
Radio bursts from deep space
For the last 10 years radio astronomers have been detecting short-duration, strong bursts of radio waves from unknown astronomical sources outside our own Galaxy. The discovery of these fast radio bursts (FRBs) sparked a lot of interest, because the estimated distances to the FRBs is 100s of millions to billions of light years. It is an astrophysical puzzle how radio bursts of such intensity can be produced.
Astro-archaeology with the APEX telescope: A historical star collision as novel source of interstellar molecules
The APEX telescope in Chile observed the sky position of the oldest historical nova, first discovered in 1670. Very surprisingly, emission from a multitude of different, even organic molecules was detected. Their peculiar isotopologic composition suggests that by no means ”normal” interstellar gas is observed, but rather material that was set free in a collision of two stars. This completely new source of interstellar molecular emission permits investigations of the end products of stellar collisions, a process that possibly occurs much more frequently than previously thought.