News aus der Fakultät

14.04.2021

Telescopes unite in unprecedented observations of a famous black hole

Astrophysicists of the University of Tübingen have been involved in a large, worldwide collaborative effort to observe the black hole M87 and its jet system all across the electromagnetic spectrum, during the observation campaign conducted with the Event Horizon Telescope that led to the first image of a black hole.

Composite image showing how the M87 system looked, across the entire electromagnetic spectrum, during the Event Horizon Telescope’s April 2017 campaign to take the iconic first image of a black hole. Requiring 19 different facilities on the Earth and in space, this image reveals the enormous scales spanned by the black hole and it forward-pointing jet, launched just outside the event horizon and spanning the entire galaxy.

In April 2019, the Event Horizon Telescope Collaboration released the first image of a black hole, using radio observations obtained with the Event Horizon Telescope (EHT) from the center of the M87 galaxy. The EHT observations, which were performed in 2017, were accompanied at that time by observations conducted with 19 observatories across the globe and in space. After intensive scrutinization by the EHT multiwavelength team, these data have now been released.

Several members of the Institute for Astronomy and Astrophysics Tübingen (IAAT) are involved in the H.E.S.S. collaboration that runs the H.E.S.S. telescopes in Namibia. H.E.S.S. provides data in the teraelectronvolt (TeV) regime and continues to participate in several EHT multiwavelength observations, including those of M87 in 2017. TeV data are especially relevant for the study of cosmic ray acceleration, which is ongoing in the jets of M87 that are emerging from the central black hole. IAAT plays a key role in the coordination of the H.E.S.S. participations in EHT multiwavelength campaigns.

Press release of the Event Horizon Telescope Multiwavelength Team with more information

https://eventhorizontelescope.org/blog/telescopes-unite-unprecedented-observations-famous-black-hole

Original publication

“Broadband Multi-wavelength Properties of M87 During the 2017 Event Horizon Telescope Campaign"
EHT MWL Science Working Group et al. 2021, the Astrophysical Journal Letters, 911, L11,
https://doi.org/10.3847/2041-8213/abef71
https://iopscience.iop.org/article/10.3847/2041-8213/abef71

Contact at the Institute for Astronomy and Astrophysics Tübingen

Gerd Pühlhofer

Images obtained with the different observatories and an animation

The picture above and the video linked below show the images of M87 and its jet system, as obtained by the different observatories during the 2017 EHT MWL campaign. Image scales are largely different at the different wavelengths, reflecting the different angular resolutions that are available with the respective instruments. The EHT image provides microarcsecond resolution, which has permitted to resolve the shadow of the black hole. TeV observations at the other end of the electromagnetic spectrum do not provide angular resolution to resolve even the central jet system as imaged in most of the other wavebands, information is encoded in time variability and energy spectra.

Video on Youtube
Downloadable MP4

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