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.
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.
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.