English

Accretion in Active Galactic Nuclei

High Energy Astrophysical Phenomena 2019-02-07 v2

Abstract

We review the current status of the understanding how the accretion onto the central black hole proceeds in Active Galaxies. Standard accretion disk is a key element in all relatively bright active galaxies like Seyferts and quasars, although it is not present in very low luminosity sources, like Sgr A*. However, the standard disk does not explain the broad band spectrum, so the disk has to be supplemented with a number of additional components, and our deeper understanding of these components is still far from being complete. These additional elements are: compact hard X-ray corona, inner hot flow, warm corona, disk wind and the Broad Line Region, and finally dusty/molecular torus. All these elements seem to be needed in various proportions, depending predominantly on the Eddington ratio of a given source. These elements also interact with each other which is not yet fully taken into account.

Keywords

Cite

@article{arxiv.1811.04326,
  title  = {Accretion in Active Galactic Nuclei},
  author = {Bozena Czerny and Mohammad-Hassan Naddaf},
  journal= {arXiv preprint arXiv:1811.04326},
  year   = {2019}
}

Comments

17 pages, 7 figures, Accepted for publication on PoS Proceedings, Contribution "PoS(APCS2018)006" to the Conference on "Accretion Processes in Cosmic Sources", Saint Petersburg, Russia

R2 v1 2026-06-23T05:11:37.037Z