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Scientists reveal 30-year secret of huge X-ray flares of black holes

Published by Oleksandr Fedotkin

Astrophysicists using NASA’s IXPE orbiting telescope were able to understand the origin of X-rays in jets supermassive black holes.

Scientists used IXPE and ground-based radio and optical telescopes to observe blazars BL Lacertae in Lizard constellations. They tried to answer the long-standing question of how X-rays are produced in such extreme conditions.

Based on the results of their observations, the scientists concluded that X-rays are most likely produced by the interaction between electrons and photons accelerated to almost the speed of light. For many years, scientists have been arguing over whether X-rays are produced in jets supermassive black holes from electrons or protons.

NASA/Pablo Garcia

The polarization of light indicates the direction of electromagnetic waves. With high polarization, the source of X-rays must be protons spinning in a spiral in magnetic fields jets, or interact with photons. At a lower degree of polarization, electrons play a role in the generation of X-rays due to Compton scattering. Thus, electrons moving at almost the speed of light collide with infrared photons and increase their energy to the level of X-rays.

Currently, the IXPE telescope, launched on December 9, 2021, remains the only such device capable of measuring the polarization level of X-rays in blazar jets. IXPE helped scientists learn that in blazar jets, electrons have enough energy to scatter photons of infrared light up to X-ray wavelengths.

IXPE observed the blazar BL Lac. in late November 2023 for seven days with several ground-based telescopes that measured optical and radio frequency polarization simultaneously. During the X-ray polarization observations, the optical polarization of this blazar reached 47.5%.

«This was not only the most polarized blazar in the last 30 years, it was the most polarized blazar ever observed!», — emphasizes one of the leading authors of the study from the FORTH Institute of Astrophysics in Greece, Ioannis Liodakis.

However, the observation The IXPE data indicate that the X-ray radiation was much less polarized, by no more than 7.6%. This means that the interaction of electrons with photons due to Compton scattering should explain the X-ray emission. 

The results of the study were published on the preprint server Arxiv

Source: SkiTechDaily