2007/11/30 by Steven Diehl, Thomas S. Statler · 39 citations
Engineering · Physics and Astronomy · #Active galactic nucleus #Astronomy and Astrophysical Research #Asymmetry #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy merger #Gravitation #Hydrostatic equilibrium #Interstellar medium #Radio galaxy #Space Technology and Applications #astro-ph
paper · pdf · doi:10.1086/587481
published in The Astrophysical Journal 680(2), 897-910 (IOP Publishing) · 15 pages, 12 figures, emulateapj, minor modifications for referee, fixed radio luminosities which were off by 10^3 in previous version
arxiv created 2008/02/08 · openalex publication_date 2008/06/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/09
We report on the discovery of a new quantitative relationship between X-ray gas morphology and radio and X-ray AGN luminosities in normal elliptical galaxies. This is the second paper in a series using data on 54 objects from the Chandra public archive and builds on the findings of Paper I, which demonstrated that hydrostatic equilibrium in elliptical galaxies holds, at best, only approximately and that the shape of the X-ray isophotes is unrelated to the shape of the gravitational potential. Instead, the gas is almost always asymmetrically disturbed. In this paper we quantify the amount of asymmetry and study its correlation with other galaxy properties. We also determine radio powers and derive X-ray AGN luminosities for our galaxy sample. We find that the amount of asymmetry in the gas is correlated with both measures of AGN activity, in the sense that the hot gas is more disturbed in galaxies with higher radio and X-ray AGN luminosities. We find no evidence that galaxy density has significant effects on gas morphology. We do, however, find evidence for a correlation between gas asymmetry and the presence of hot ambient gas, which we interpret as a signature of hydrodynamic interactions with an external ambient medium. Surprisingly, the AGN-morphology connection persists all the way down to the weakest AGN luminosities in rather X-ray-faint galaxies. This is strong morphological evidence that supports the general importance of AGN feedback, even in normal elliptical galaxies.