2005/07/05 by N. A. Grogin, C. J. Conselice, E. Chatzichristou +13 · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/432256
published as Astrophys.J.627:L97-L100,2005 · Astrophysical Journal Letters, in press. Figure 1 available at full resolution upon request
arxiv created 2005/07/05 · arxiv updated 2009/12/01
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 z850 ~ 26.6, including the resolved hosts of 322 X-ray-selected AGNs. Distributions of (1) z850 asymmetry for 130 AGN hosts at z850 < 23 and (2) near-neighbor counts for 173 AGN hosts at z850 < 24 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 z850 concentrations for the AGN hosts is offset by +0.5 compared to the non-AGN, a 6.4-sigma 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.