AGN host galaxies at z ~ 0.4-1.3:bulge-dominated and lacking merger-AGN connection

Grogin, N. A. and Conselice, C. J. and Chatzichristou, E. and Alexander, D. M. and Bauer, F. E. and Hornschemeier, A. E. and Jogee, S. and Koekemoer, A. M. and Laidler, V. G. and Livio, M. and Lucas, R. A. and Paolillo, M. and Ravindranath, S. and Schreier, E. J. and Simmons, B. D. and Urry, C. M. (2005) AGN host galaxies at z ~ 0.4-1.3:bulge-dominated and lacking merger-AGN connection. The Astrophysical Journal, 627 (2). L97-L100. ISSN 0004-637X

Abstract

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 , including z850 ≈ 26.6 the resolved hosts of 322 X-ray–selected AGNs. Distributions of (1) asymmetry for 130 AGN hosts z z 850 850 ! 23 and (2) near-neighbor counts for 173 AGN hosts are both consistent with non-AGN control samples. z850 ! 24 This implies no close connection between recent galaxy mergers and moderate-luminosity AGN activity out to appreciable look-back times ( ), approaching the epoch of peak AGN activity in the universe. The distri- z 1.3 bution of z850 C for the AGN hosts is offset by compared to the non-AGN, a 6.4 DC ≈ 0.5 j 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.