%0 Generic %1 lehmer2013concurrent %A Lehmer, B. D. %A Lucy, A. B. %A Alexander, D. M. %A Best, P. N. %A Geach, J. E. %A Harrison, C. M. %A Hornschemeier, A. E. %A Matsuda, Y. %A Mullaney, J. R. %A Smail, Ian %A Sobral, D. %A Swinbank, A. M. %D 2013 %K black clusters hole %T Concurrent Supermassive Black Hole and Galaxy Growth: Linking Environment and Nuclear Activity in z = 2.23 H-alpha Emitters %U http://arxiv.org/abs/1301.3922 %X We present results from a ~100 ks Chandra observation of the 2QZ Cluster 1004+00 structure at z = 2.23 (hereafter, 2QZ Clus). 2QZ Clus was originally identified as an overdensity of four optically-selected QSOs at z = 2.23 within a 15x15 arcmin^2 region. Narrow-band imaging in the near-IR revealed that the structure contains an additional overdensity of 22 z = 2.23 Halpha-emitting galaxies (HAEs), resulting in 23 unique z = 2.23 HAEs/QSOs. Our Chandra observations reveal that 3 HAEs in addition to the 4 QSOs harbor powerfully accreting supermassive black holes (SMBHs), with 2-10 keV luminosities of ~(8-60) x 10^43 ergs/s and X-ray spectral slopes consistent with unobscured AGN. Using a large comparison sample of 210 HAEs in Chandra-COSMOS (C-COSMOS), we find suggestive evidence that the AGN fraction increases with local HAE galaxy density. The 2QZ Clus HAEs reside in a moderately overdense environment (a factor of ~2 times over the field), and after excluding optically-selected QSOs, we find the AGN fraction is a factor of ~3.5^+3.8_-2.2 times higher than C-COSMOS HAEs in similar environments. Using stacking analyses of the Chandra data and Herschel SPIRE observations at 250 um, we respectively estimate mean SMBH accretion rates (Mdot) and star-formation rates (SFRs) for the 2QZ Clus and C-COSMOS samples. We find that the mean 2QZ Clus HAE stacked 2-10 keV luminosity is QSO-like (~6-10 x 10^43 ergs/s), and the implied Mdot/SFR \sim (1.6-3.2) x10^-3 is broadly consistent with the local MBH/M* relation and z ~ 2 X-ray selected AGN. The C-COSMOS HAEs are on average an order of magnitude less X-ray luminous and have Mdot/SFR (0.2-0.4) x10^-3, comparable to z ~ 1-2 star-forming galaxies with similar mean X-ray luminosities. We estimate that a periodic QSO phase with duty cycle ~2-8% would be sufficient to bring the star-forming galaxies onto the local MBH/M* relation.

@misc{lehmer2013concurrent, abstract = {We present results from a ~100 ks Chandra observation of the 2QZ Cluster 1004+00 structure at z = 2.23 (hereafter, 2QZ Clus). 2QZ Clus was originally identified as an overdensity of four optically-selected QSOs at z = 2.23 within a 15x15 arcmin^2 region. Narrow-band imaging in the near-IR revealed that the structure contains an additional overdensity of 22 z = 2.23 Halpha-emitting galaxies (HAEs), resulting in 23 unique z = 2.23 HAEs/QSOs. Our Chandra observations reveal that 3 HAEs in addition to the 4 QSOs harbor powerfully accreting supermassive black holes (SMBHs), with 2-10 keV luminosities of ~(8-60) x 10^43 ergs/s and X-ray spectral slopes consistent with unobscured AGN. Using a large comparison sample of 210 HAEs in Chandra-COSMOS (C-COSMOS), we find suggestive evidence that the AGN fraction increases with local HAE galaxy density. The 2QZ Clus HAEs reside in a moderately overdense environment (a factor of ~2 times over the field), and after excluding optically-selected QSOs, we find the AGN fraction is a factor of ~3.5^+3.8_-2.2 times higher than C-COSMOS HAEs in similar environments. Using stacking analyses of the Chandra data and Herschel SPIRE observations at 250 um, we respectively estimate mean SMBH accretion rates (Mdot) and star-formation rates (SFRs) for the 2QZ Clus and C-COSMOS samples. We find that the mean 2QZ Clus HAE stacked 2-10 keV luminosity is QSO-like (~6-10 x 10^43 ergs/s), and the implied Mdot/SFR \sim (1.6-3.2) x10^-3 is broadly consistent with the local MBH/M* relation and z ~ 2 X-ray selected AGN. The C-COSMOS HAEs are on average an order of magnitude less X-ray luminous and have Mdot/SFR \sim (0.2-0.4) x10^-3, comparable to z ~ 1-2 star-forming galaxies with similar mean X-ray luminosities. We estimate that a periodic QSO phase with duty cycle ~2-8% would be sufficient to bring the star-forming galaxies onto the local MBH/M* relation.}, added-at = {2013-01-18T18:50:07.000+0100}, author = {Lehmer, B. D. and Lucy, A. B. and Alexander, D. M. and Best, P. N. and Geach, J. E. and Harrison, C. M. and Hornschemeier, A. E. and Matsuda, Y. and Mullaney, J. R. and Smail, Ian and Sobral, D. and Swinbank, A. M.}, biburl = {https://www.bibsonomy.org/bibtex/209db61695a8b6be94d6e3f0eda54f40b/miki}, description = {[1301.3922] Concurrent Supermassive Black Hole and Galaxy Growth: Linking Environment and Nuclear Activity in z = 2.23 H-alpha Emitters}, interhash = {664c898c95dbe1ba3f224f20549245a5}, intrahash = {09db61695a8b6be94d6e3f0eda54f40b}, keywords = {black clusters hole}, note = {cite arxiv:1301.3922Comment: 11 pages, 5 figures, accepted for publication in ApJ}, timestamp = {2013-01-18T18:50:08.000+0100}, title = {Concurrent Supermassive Black Hole and Galaxy Growth: Linking Environment and Nuclear Activity in z = 2.23 H-alpha Emitters}, url = {http://arxiv.org/abs/1301.3922}, year = 2013 }