AGN Host Galaxies at z 6 0.4-1.3: Bulge-dominated and Lacking Merger-AGN Connection

• Published in: The Astrophysical journal 2005-07, Vol.627 (2), p.L97-L100
• Main Authors: Grogin, NA, Conselice, C J, Chatzichristou, E, Alexander, D M, Bauer, F E, Hornschemeier, A E, Jogee, S, Koekemoer, A M, Laidler, V G, Livio, M, Lucas, R A, Paolillo, M, Ravindranath, S, Schreier, E J
• Format: Article
• Language: English
• ISSN: 0004-637X

We investigate morphological structure parameters and local environments of distant moderate-luminosity active galactic nucleus (AGN) host galaxies in the overlap between the HST/ACS observations of the Great Observatories Origins Deep Survey (GOODS) and the two Chandra Deep Fields. We compute near-neighbor counts and BViz asymmetry (A) and concentration (C) indices for -35,500 GOODS/ACS galaxies complete to z sub(850) - 26.6, including the resolved hosts of 322 X-ray-selected AGNs. Distributions of (1) z sub(850) asymmetry for 130 z sub(850) < 23 AGN hosts and (2) near-neighbor counts for 173 z sub(850) < 24 AGN hosts are both consistent with non-AGN control samples. This implies no close connection between recent galaxy mergers and moderate-luminosity AGN activity out to appreciable look-back times (z 1.3), approaching the epoch of peak AGN activity in the universe. The distribution of z sub(850) C for the AGN hosts is offset by C - +0.5 compared to the non-AGN, a 6.4 s discrepancy much larger than can be explained by the possible influence of unresolved emission from the AGN or a circumnuclear starburst. The local universe association between AGN and bulge-dominated galaxies thus persists to substantial look-back time. We discuss implications in the context of the low-redshift supermassive central black hole mass correlation with host galaxy properties, including concentration.