%0 Generic %1 onoue2020redshift %A Onoue, Masafusa %A Bañados, Eduardo %A Mazzucchelli, Chiara %A Venemans, Bram P. %A Schindler, Jan-Torge %A Walter, Fabian %A Hennawi, Joseph F. %A Andika, Irham Taufik %A Davies, Frederick B. %A Decarli, Roberto %A Farina, Emanuele P. %A Jahnke, Knud %A Nagao, Tohru %A Tominaga, Nozomu %A Wang, Feige %D 2020 %K library %T No Redshift Evolution in the Broad Line Region Metallicity up to z=7.54: Deep NIR Spectroscopy of ULAS J1342+0928 %U http://arxiv.org/abs/2006.16268 %X We present deep (9 hours) Gemini-N/GNIRS near-infrared spectroscopic observations of ULAS J1342+0928, a luminous quasar at z=7.54. Various broad emission lines were detected, as well as the underlying continuum and iron forests over the rest-frame wavelength 970-2930A. There is a clear trend that higher-ionization emission lines show larger blueshifts with CIV1549 exhibiting 5510^+240_-110 km s-1 blueshift with respect to the systematic redshift from the far-infrared CII 158um emission line. Those high ionization lines have wide profiles with FWHM more than 10000 km s-1. A modest blueshift of 340^+110_-80 km s-1 is also seen in MgII, the lowest ionization line identified in the spectrum. The updated MgII-based black hole mass of M_BH=9.1_-1.3^+1.4 x 10^8 M_sun and the Eddington ratio of L_bol/L_Edd=1.1_-0.2^+0.2 confirm that ULAS J1342+0928 is powered by a massive and actively accreting black hole. There is no significant difference in the emission line ratios such as SiIV/CIV and AlIII/CIV when compared to lower-redshift quasars in a similar luminosity range, which suggests early metal pollution of the broad-line-region clouds. This trend also holds for the FeII/MgII line ratio, known as a cosmic clock that traces the iron enrichment in the early universe. Different iron templates and continuum fitting ranges were used to explore how the FeII/MgII measurement changes as a function of spectral modeling. Quasars at even higher redshift or at fainter luminosity range (L_bol<10^46 erg s-1) are needed to probe the sites of early metal enrichment and a corresponding change in the FeII/MgII ratio.

@misc{onoue2020redshift, abstract = {We present deep (9 hours) Gemini-N/GNIRS near-infrared spectroscopic observations of ULAS J1342+0928, a luminous quasar at z=7.54. Various broad emission lines were detected, as well as the underlying continuum and iron forests over the rest-frame wavelength 970-2930A. There is a clear trend that higher-ionization emission lines show larger blueshifts with CIV1549 exhibiting 5510^{+240}_{-110} km s-1 blueshift with respect to the systematic redshift from the far-infrared [CII] 158um emission line. Those high ionization lines have wide profiles with FWHM more than 10000 km s-1. A modest blueshift of 340^{+110}_{-80} km s-1 is also seen in MgII, the lowest ionization line identified in the spectrum. The updated MgII-based black hole mass of M_BH=9.1_{-1.3}^{+1.4} x 10^8 M_sun and the Eddington ratio of L_bol/L_Edd=1.1_{-0.2}^{+0.2} confirm that ULAS J1342+0928 is powered by a massive and actively accreting black hole. There is no significant difference in the emission line ratios such as SiIV/CIV and AlIII/CIV when compared to lower-redshift quasars in a similar luminosity range, which suggests early metal pollution of the broad-line-region clouds. This trend also holds for the FeII/MgII line ratio, known as a cosmic clock that traces the iron enrichment in the early universe. Different iron templates and continuum fitting ranges were used to explore how the FeII/MgII measurement changes as a function of spectral modeling. Quasars at even higher redshift or at fainter luminosity range (L_bol<10^46 erg s-1) are needed to probe the sites of early metal enrichment and a corresponding change in the FeII/MgII ratio.}, added-at = {2020-07-01T07:50:16.000+0200}, author = {Onoue, Masafusa and Bañados, Eduardo and Mazzucchelli, Chiara and Venemans, Bram P. and Schindler, Jan-Torge and Walter, Fabian and Hennawi, Joseph F. and Andika, Irham Taufik and Davies, Frederick B. and Decarli, Roberto and Farina, Emanuele P. and Jahnke, Knud and Nagao, Tohru and Tominaga, Nozomu and Wang, Feige}, biburl = {https://www.bibsonomy.org/bibtex/2c2a5914e573f3ce08dd7ddbd5427413e/gpkulkarni}, description = {No Redshift Evolution in the Broad Line Region Metallicity up to z=7.54: Deep NIR Spectroscopy of ULAS J1342 0928}, interhash = {7e3f7b678063e54b79068daa34bcd11c}, intrahash = {c2a5914e573f3ce08dd7ddbd5427413e}, keywords = {library}, note = {cite arxiv:2006.16268Comment: 21 pages, 8 figures, 3 tables, accepted for publication in ApJ}, timestamp = {2020-07-01T07:50:16.000+0200}, title = {No Redshift Evolution in the Broad Line Region Metallicity up to z=7.54: Deep NIR Spectroscopy of ULAS J1342+0928}, url = {http://arxiv.org/abs/2006.16268}, year = 2020 }