Tomasz Nowakowski is a writer for Phys.org.
Astronomers from the Harvard-Smithsonian Center for Astrophysics (CfA) and elsewhere used NASA's Chandra X-ray observatory to investigate an active galaxy called Markarian 78. The source has X-ray emission and shocks. A paper detailing the study was published on arXiv.org.
Black holes in the center of some galaxies emit powerful, high-energy radiation as they accrete gas and dust. Even on megaparsec scales, these nuclei can form jets, having mostly cylindrical, conical or parabolic shapes. AGNs are referred to as active galaxies.
Markarian 78 is a type II Seyfert galaxy with an estimated size of 2,400 light years, which is far away from the Earth. The source of the mid-IR emission is dominated by AGN-heated dust and has a luminosity between 8 and 12 tredecillion erg/s.
Mrk 78's radio jet is accelerated by the ionized gas that it encounters. It was found that the radio jet is disrupted by a compact cloud and expands into a bubble.
A team of scientists led by the CfA's Francesca M. Fornasini conducted X-ray observations of the central AGN in order to get a better view of the physical mechanisms that impact the gas in Mrk 78. The results were compared to previous studies.
The inner region of Mrk 78 was imaged at sub-arcsecond resolution in X-rays, and they found a complex morphology with variations on scales from 650 to 6,500 light years. Although the observations detected a knot of X-rays on the Eastern side of the source, it turns out that the Western side is dominated by an extended loop of X-ray emission.
In the extended emission regions, the astronomer identified a complex spectrum requiring at least two components, either photoionized or thermal. The models that include thermal models represent the shocked emission preferred by the spectral fitting of this extended emission.
The thermal energy that may be injected into the interstellar medium is between 200 and 600 duodecillion erg/s, according to the scientists. The total power released by the shocks in these regions is estimated to be in the range of 200 and 2,000 duodecillion erg/s.
The shocks on the Western side of Mrk 78 are more frequent than on the Eastern side. They think that soft X-ray shocked emission closer to the nucleus may be too hot to cool quickly. The authors of the paper believe that the two hypotheses are the most plausible explanations for the offset of the Western X-ray emission.
More information: Francesca M. Fornasini et al, Termination Shocks and the Extended X-ray Emission in Mrk 78. arXiv:2204.13140v1 [astro-ph.HE], arxiv.org/abs/2204.13140The Science X Network will be launched in 2022.
Citation: Study reveals termination shocks and extended X-ray emission in the active galaxy Markarian 78 (2022, May 9) retrieved 9 May 2022 from https://phys.org/news/2022-05-reveals-termination-x-ray-emission-galaxy.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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