%0 Generic %1 Kocevski2011 %A Kocevski, Dale D. %A Faber, S. M. %A Mozena, Mark %A Koekemoer, Anton M. %A Nandra, Kirpal %A Rangel, Cyprian %A Laird, Elise S. %A Brusa, Marcella %A Wuyts, Stijn %A Trump, Jonathan R. %A Koo, David C. %A Somerville, Rachel S. %A Bell, Eric F. %A Lotz, Jennifer M. %A Alexander, David M %A Bournaud, Frederic %A Conselice, Christopher J. %A Dahlen, Tomas %A Dekel, Avashi %A Donley, Jennifer L. %A Dunlop, James S. %A Finoguenov, Alexis %A Georgakakis, Antonis %A Giavalisco, Mauro %A Guo, Yicheng %A Grogin, Norman A. %A Hathi, Nimish P. %A Juneau, Stephanie %A Kartaltepe, Jeyhan S. %A Lucas, Ray A. %A McGrath, Elizabeth J. %A McIntosh, Daniel H. %A Mobasher, Bahram %A Robaina, Aday R. %A Rosario, David %A Straughn, Amber N. %A van der Wel, Arjen %A Villforth, Carolin %D 2011 %K AGN mergers processes secular %T CANDELS: Constraining the AGN-Merger Connection with Host Morphologies at z~2 %U http://arxiv.org/abs/1109.2588 %X Using HST/WFC3 imaging taken as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), we examine the role that major galaxy mergers play in triggering active galactic nuclei (AGN) activity at z~2. Our sample consists of 72 moderate-luminosity (Lx ~ 1E42-1E44 erg/s) AGN at 1.5<z<2.5 that are selected using the 4 Msec Chandra observations in the Chandra Deep Field South, the deepest X-ray observations to date. Employing visual classifications, we have analyzed the rest-frame optical morphologies of the AGN host galaxies and compared them to a mass-matched control sample of 216 non-active galaxies at the same redshift. We find that most of the AGN reside in disk galaxies (51.4%), while a smaller percentage are found in spheroids (27.8%). Roughly 16.7% of the AGN hosts have highly disturbed morphologies and appear to be involved in a major merger or interaction, while most of the hosts (55.6%) appear relatively relaxed and undisturbed. These fractions are statistically consistent with the fraction of control galaxies that show similar morphological disturbances. These results suggest that the hosts of moderate-luminosity AGN are no more likely to be involved in an ongoing merger or interaction relative to non-active galaxies of similar mass at z~2. The high disk fraction observed among the AGN hosts also appears to be at odds with predictions that merger-driven accretion should be the dominant AGN fueling mode at z~2, even at moderate X-ray luminosities. Although we cannot rule out that minor mergers are responsible for triggering these systems, the presence of a large population of relatively undisturbed disk-like hosts suggests that secular processes play a greater role in fueling AGN activity at z~2 than previously thought.

@misc{Kocevski2011, abstract = { Using HST/WFC3 imaging taken as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), we examine the role that major galaxy mergers play in triggering active galactic nuclei (AGN) activity at z~2. Our sample consists of 72 moderate-luminosity (Lx ~ 1E42-1E44 erg/s) AGN at 1.5<z<2.5 that are selected using the 4 Msec Chandra observations in the Chandra Deep Field South, the deepest X-ray observations to date. Employing visual classifications, we have analyzed the rest-frame optical morphologies of the AGN host galaxies and compared them to a mass-matched control sample of 216 non-active galaxies at the same redshift. We find that most of the AGN reside in disk galaxies (51.4%), while a smaller percentage are found in spheroids (27.8%). Roughly 16.7% of the AGN hosts have highly disturbed morphologies and appear to be involved in a major merger or interaction, while most of the hosts (55.6%) appear relatively relaxed and undisturbed. These fractions are statistically consistent with the fraction of control galaxies that show similar morphological disturbances. These results suggest that the hosts of moderate-luminosity AGN are no more likely to be involved in an ongoing merger or interaction relative to non-active galaxies of similar mass at z~2. The high disk fraction observed among the AGN hosts also appears to be at odds with predictions that merger-driven accretion should be the dominant AGN fueling mode at z~2, even at moderate X-ray luminosities. Although we cannot rule out that minor mergers are responsible for triggering these systems, the presence of a large population of relatively undisturbed disk-like hosts suggests that secular processes play a greater role in fueling AGN activity at z~2 than previously thought. }, added-at = {2011-09-15T01:46:50.000+0200}, author = {Kocevski, Dale D. and Faber, S. M. and Mozena, Mark and Koekemoer, Anton M. and Nandra, Kirpal and Rangel, Cyprian and Laird, Elise S. and Brusa, Marcella and Wuyts, Stijn and Trump, Jonathan R. and Koo, David C. and Somerville, Rachel S. and Bell, Eric F. and Lotz, Jennifer M. and Alexander, David M and Bournaud, Frederic and Conselice, Christopher J. and Dahlen, Tomas and Dekel, Avashi and Donley, Jennifer L. and Dunlop, James S. and Finoguenov, Alexis and Georgakakis, Antonis and Giavalisco, Mauro and Guo, Yicheng and Grogin, Norman A. and Hathi, Nimish P. and Juneau, Stephanie and Kartaltepe, Jeyhan S. and Lucas, Ray A. and McGrath, Elizabeth J. and McIntosh, Daniel H. and Mobasher, Bahram and Robaina, Aday R. and Rosario, David and Straughn, Amber N. and van der Wel, Arjen and Villforth, Carolin}, biburl = {https://www.bibsonomy.org/bibtex/2c8f312f01afbcb2527957de813fa1ad5/miki}, description = {[1109.2588] CANDELS: Constraining the AGN-Merger Connection with Host Morphologies at z~2}, interhash = {b03bda9a05a1e4a5a558a031682687d6}, intrahash = {c8f312f01afbcb2527957de813fa1ad5}, keywords = {AGN mergers processes secular}, note = {cite arxiv:1109.2588 Comment: 10 Pages, 5 Figures, Revised draft submitted to ApJ}, timestamp = {2011-09-15T01:46:50.000+0200}, title = {CANDELS: Constraining the AGN-Merger Connection with Host Morphologies at z~2}, url = {http://arxiv.org/abs/1109.2588}, year = 2011 }