A unified look at a famous black hole in M87

In April 2019, scientists released the first image of a black hole in the galaxy M87 using the Event Horizon Telescope (EHT). Now data from nineteen observatories, including MAGIC, are being released that promise to give unparalleled insight into this black hole and the system it powers, and to improve tests of Einstein’s General Theory of Relativity. See the full press release of the EHT here.

The paper entitled “Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign” is just accepted in ApJ Letters (arXiv:2104.06855):

In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass approximately 6.5 x 10^9 M_solar. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous gamma-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the gamma-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.

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This entry was posted on Friday, April 16th, 2021 at 00:43 and is filed under Astronomy, MAGIC, Publications, Work. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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