This supports the magnetized accretion disk model. A collaboration with the Event Horizon Telescope (EHT) has discovered circularly polarized radiation from the immediate vicinity of the supermassive black hole in galaxy M87. This suggests that the magnetized accretion disk model can be better applied to describe processes in the vicinity of black holes. This article was published in “The Astrophysical Journal Letters”.

A team of EHT astronomers led by Andrew Chael of Princeton University has found convincing evidence of circularly polarized radiation from the immediate vicinity of the supermassive black hole in galaxy M87. This discovery was made during analysis of EHT observation data from April 2017. The circular polarization of synchrotron radiation near a black hole provides important information about the strength of the magnetic field and the type of particles producing the radiation. In particular, it can be determined whether the observed radiation originates primarily from electron-positron plasma or electron-ion plasma. However, circularly polarized light was more difficult to detect than linearly polarized radiation.

The researchers found that the observed radiation from the black hole’s shadow was less than 4 percent circularly polarized, which is in line with the lower degree of circular polarization estimated from previous observations with other telescopes. It was a match. Scientists also face new constraints on models of M87’s supermassive black hole, including hydrodynamic models of the accretion flow with stronger rather than weak magnetic fields penetrating the plasma and influencing the accretion process. Preference was given to models with high ionic temperatures. electron ratio.

source:

https://iopscience.iop.org/article/10.3847/2041-8213/acff70#artAbst