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

Journal Article · Thu Mar 20 04:00:00 EDT 2014 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/784/1/L9· OSTI ID:22365965

Fan, Lulu; Chen, Yang; Li, Jinrong; Lv, Xuanyi; Kong, Xu ^[1]; Fang, Guanwen ^[2]

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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)

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 sample 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.

• OSTI ID: 22365965
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 784; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASYMMETRY
BRIGHTNESS
CONCENTRATION RATIO
GALACTIC EVOLUTION
GALAXY NUCLEI
INDEXES
MASS
MORPHOLOGY
RED SHIFT
SPACE
TELESCOPES
TWO-DIMENSIONAL CALCULATIONS
UNIVERSE
X RADIATION
X-RAY GALAXIES