2011/12/15 by Kentaro Nagamine, Nagamine, Kentaro, Paramita Barai +3
Engineering · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Heat Transfer Mechanisms #High Energy Astrophysical Phenomena (astro-ph.HE) #astro-ph.CO #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.48550/arxiv.1112.3525
5 pages, 3 figures. Conference proceedings of "AGN Winds in Charleston", Charleston, SC, Oct 15-18, 2011. Ed. by G. Chartas, et al. To be published by ASP. Updated one reference
openalex publication_date 2011/12/15 · arxiv created 2012/01/11 · arxiv updated 2012/01/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the gas accretion onto a supermassive black hole (SMBH) using the 3D SPH code GADGET-3 on scales of 0.1-200 pc. First we test our code with spherically symmetric, adiabatic Bondi accretion problem. We find that our simulation can reproduce the expected Bondi accretion flow very well for a limited amount of time until the effect of outer boundary starts to be visible. We also find artificial heating of gas near the inner accretion boundary due to the artificial viscosity of SPH. Second, we implement radiative cooling and heating due to X-rays, and examine the impact of thermal feedback by the central X-ray source. The accretion flow roughly follows the Bondi solution for low central X-ray luminosities, however, the flow starts to exhibit non-spherical fragmentation due to thermal instability for a certain range of central LX, and a strong overall outflow develops for greater LX. The cold gas develops filamentary structures that fall into the central SMBH, whereas the hot gas tries to escape through the channels in-between the cold filaments. Such fragmentation of accreting gas can assist in the formation of clouds around AGN, induce star-formation, and contribute to the observed variability of narrow-line regions.