Morphologies of low-redshift AGN host galaxies: what role dies AGN luminosity play?

Abstract

Elizabeth J. McGrath Department of Physics and Astronomy, Colby College, Waterville, ME 04901, USA Arjen van der Wel & YuYen Chang Max Planck Institute for Astronomy, Konigstuhl 17, 69117 Heidelberg, Germany Yicheng Guo University of Massachusetts, Department of Astronomy, 710 North Pleasant Street, Amherst, MA, USA The CANDELS Collaboration Mergers of galaxies have been suspected to be a major trigger of AGN activity for many years. However, when compared to carefully matched control samples, AGN host galaxies often show no enhanced signs of interaction. A common explanation for this lack of observed association between AGN and mergers has often been that while mergers are of importance for triggering AGN, they only dominate at the very high luminosity end of the AGN population. In this study, we compare the morphologies of AGN hosts to a carefully matched control sample and particularly study the role of AGN luminosity. We find no enhanced merger rates in AGN hosts and also find no trend for stronger signs of disturbance at higher AGN luminosities. While this study does not cover very high luminosity AGN, we can exclude a strong connection between AGN and mergers over a wide range of AGN luminosities and therefore for a large part of the AGN population. The Extreme sky: Sampling the Universe above 10 keV extremesky2009, November 6-8, 2012 Max-Planck-Insitut fur Radioastronomie (MPIfR), Bonn, Germany