Evidence for Quasar Activity Triggered by Galaxy Mergers inHSTObservations of Dust‐reddened Quasars

Citations Over TimeTop 10% of 2008 papers

Abstract

We present Hubble Space Telescope ACS images of 13 dust-reddened type 1 quasars selected from the FIRST/2MASS Red Quasar Survey. These quasars have high intrinsic luminosities after correction for dust obscuration (–23.5 ≥ M_B ≥ − 26.2 from K-magnitude). The images show strong evidence of recent or ongoing interaction in 11 of the 13 cases, even before the quasar nucleus is subtracted. None of the host galaxies are well fit by a simple elliptical profile. The fraction of quasars showing interaction is significantly higher than the 30% seen in samples of host galaxies of normal, unobscured quasars. There is a weak correlation between the amount of dust reddening and the magnitude of interaction in the host galaxy, measured using the Gini coefficient and the concentration index. Although few host galaxy studies of normal quasars are matched to ours in intrinsic quasar luminosity, no evidence has been found for a strong dependence of merger activity on host luminosity in samples of the host galaxies of normal quasars. We thus believe that the high merger fraction in our sample is related to their obscured nature, with a significant amount of reddening occurring in the host galaxy. The red quasar phenomenon seems to have an evolutionary explanation, with the young quasar spending the early part of its lifetime enshrouded in an interacting galaxy. This might be further indication of a link between AGNs and starburst galaxies.

Related Papers

• → Properties of Radio‐selected Broad Absorption Line Quasars from the First Bright Quasar Survey(2000)252 cited
• → A comparative study of the properties of 3CR and 4C quasars(1977)17 cited
• → WFPC2 Imaging of Quasar Environments: A Comparison of LBQS and HST Archive Quasars(2001)
• → FINDING MISSING QUASARS IN THE 'REDSHIFT DESERT'(2013)
• → The main sequence of quasars: The taming of the extremes(2021)