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Title: STRUCTURE AND MORPHOLOGY OF X-RAY-SELECTED ACTIVE GALACTIC NUCLEUS HOSTS AT 1 < z < 3 IN THE CANDELS-COSMOS FIELD

We analyze morphologies of the host galaxies of 35 X-ray-selected active galactic nuclei (AGNs) at z ∼ 2 in the Cosmic Evolution Survey field using Hubble Space Telescope/WFC3 imaging taken from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. We build a control sample of 350 galaxies in total by selecting 10 non-active galaxies drawn from the same field with a similar stellar mass and redshift for each AGN host. By performing two-dimensional fitting with GALFIT on the surface brightness profile, we find that the distribution of the Sérsic index (n) of AGN hosts does not show a statistical difference from that of the control sample. We measure the nonparametric morphological parameters (the asymmetry index A, the Gini coefficient G, the concentration index C, and the M {sub 20} index) based on point-source-subtracted images. All the distributions of these morphological parameters of AGN hosts are consistent with those of the control sample. We finally investigate the fraction of distorted morphologies in both samples by visual classification. Only ∼15% of the AGN hosts have highly distorted morphologies, possibly due to a major merger or interaction. We find there is no significant difference in the distortion fractions between the AGN host samplemore » and control sample. We conclude that the morphologies of X-ray-selected AGN hosts are similar to those of non-active galaxies and most AGN activity is not triggered by a major merger.« less
Authors:
; ; ; ;  [1] ;  [2] ;  [3]
  1. Center for Astrophysics, University of Science and Technology of China, 230026 Hefei (China)
  2. Institute for Astronomy and History of Science and Technology, Dali University, Yunnan 671003 (China)
  3. Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden)
Publication Date:
OSTI Identifier:
22365965
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 784; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; BRIGHTNESS; CONCENTRATION RATIO; GALACTIC EVOLUTION; GALAXY NUCLEI; INDEXES; MASS; MORPHOLOGY; RED SHIFT; SPACE; TELESCOPES; TWO-DIMENSIONAL CALCULATIONS; UNIVERSE; X RADIATION; X-RAY GALAXIES