%0 Generic %1 derosa2013black %A De Rosa, G. %A Venemans, B. P. %A Decarli, R. %A Gennaro, M. %A Simcoe, R. A. %A Dietrich, M. %A Peterson, B. M. %A Walter, F. %A Frank, S. %A McMahon, R. G. %A Hewett, P. C. %A Mortlock, D. J. %A Simpson, C. %A Warren, S. J. %D 2013 %K black high-z hole mass %T Black hole mass estimates and emission-line properties of a sample of redshift z>6.5 quasars %U http://arxiv.org/abs/1311.3260 %X We present the analysis of optical and near-infrared spectra of the only four z>6.5 quasars known to date, discovered in the UKIDSS-LAS and VISTA-VIKING surveys. Our data-set consists of VLT/X-Shooter and Magellan/FIRE observations of the z>6.5 quasars, and includes new deep VLT/X-Shooter observations of the highest redshift quasar known to date (z=7.1). These are the best optical/NIR spectroscopic data that are likely to be obtained for the z>6.5 sample using current 6-10 m facilities. We estimate the black hole mass, the Eddington ratio, and the SiIV/CIV, CIII/CIV, and FeII/MgII emission-line flux ratios. We perform spectral modeling using a procedure that allows us to derive a probability distribution for the continuum components and to obtain the quasar properties weighted upon the underlying distribution of continuum models. The z>6.5 quasars show the same emission properties as their counterparts at lower redshifts. The z>6.5 quasars host black holes with masses of ~10^9 M_sun that are accreting close to the Eddington luminosity (<log(L_Bol/L_Edd)>= -0.4+/-0.2), in agreement with what has been observed for a sample of 4.0<z<6.5 quasars. By comparing the SiIV/CIV and CIII/CIV flux ratios with the results obtained from luminosity-matched samples at z~6 and 2<z<4.5, we find no evidence of evolution of the line ratios with cosmic time. We compare the measured FeII/MgII flux ratios with those obtained for a sample of 4.0<z<6.4 sources. The two samples are analyzed using a consistent procedure. The FeII/MgII flux ratio does not show any evolution in the 4.0<z<7.1 redshift range. Under the assumption that the FeII/MgII traces the Fe/Mg abundance ratio, this implies the presence of major episodes of chemical enrichment in the quasar hosts in the first ~0.8 Gyr after the Big Bang.

@misc{derosa2013black, abstract = {We present the analysis of optical and near-infrared spectra of the only four z>6.5 quasars known to date, discovered in the UKIDSS-LAS and VISTA-VIKING surveys. Our data-set consists of VLT/X-Shooter and Magellan/FIRE observations of the z>6.5 quasars, and includes new deep VLT/X-Shooter observations of the highest redshift quasar known to date (z=7.1). These are the best optical/NIR spectroscopic data that are likely to be obtained for the z>6.5 sample using current 6-10 m facilities. We estimate the black hole mass, the Eddington ratio, and the SiIV/CIV, CIII]/CIV, and FeII/MgII emission-line flux ratios. We perform spectral modeling using a procedure that allows us to derive a probability distribution for the continuum components and to obtain the quasar properties weighted upon the underlying distribution of continuum models. The z>6.5 quasars show the same emission properties as their counterparts at lower redshifts. The z>6.5 quasars host black holes with masses of ~10^9 M_sun that are accreting close to the Eddington luminosity (<log(L_Bol/L_Edd)>= -0.4+/-0.2), in agreement with what has been observed for a sample of 4.0<z<6.5 quasars. By comparing the SiIV/CIV and CIII]/CIV flux ratios with the results obtained from luminosity-matched samples at z~6 and 2<z<4.5, we find no evidence of evolution of the line ratios with cosmic time. We compare the measured FeII/MgII flux ratios with those obtained for a sample of 4.0<z<6.4 sources. The two samples are analyzed using a consistent procedure. The FeII/MgII flux ratio does not show any evolution in the 4.0<z<7.1 redshift range. Under the assumption that the FeII/MgII traces the Fe/Mg abundance ratio, this implies the presence of major episodes of chemical enrichment in the quasar hosts in the first ~0.8 Gyr after the Big Bang.}, added-at = {2013-11-14T16:29:52.000+0100}, author = {De Rosa, G. and Venemans, B. P. and Decarli, R. and Gennaro, M. and Simcoe, R. A. and Dietrich, M. and Peterson, B. M. and Walter, F. and Frank, S. and McMahon, R. G. and Hewett, P. C. and Mortlock, D. J. and Simpson, C. and Warren, S. J.}, biburl = {https://www.bibsonomy.org/bibtex/2b2f5f3e2cc90fcabed02988a1668ba68/miki}, description = {[1311.3260] Black hole mass estimates and emission-line properties of a sample of redshift z&gt;6.5 quasars}, interhash = {6bfd548dcc111b4b958c16a551100635}, intrahash = {b2f5f3e2cc90fcabed02988a1668ba68}, keywords = {black high-z hole mass}, note = {cite arxiv:1311.3260Comment: 21 pages, 11 figures. Submitted to ApJ}, timestamp = {2013-11-14T16:29:52.000+0100}, title = {Black hole mass estimates and emission-line properties of a sample of redshift z>6.5 quasars}, url = {http://arxiv.org/abs/1311.3260}, year = 2013 }