Physical Properties of 15 Quasars at z ≳ 6.5

Quasars are galaxies hosting accreting supermassive black holes; due to their brightness, they are unique probes of the early universe. To date, only a few quasars have been reported at z > 6.5 ( = 0.39) at a rate comparable to a luminosity-matched sample at lower redshift, albeit with significant scatter (0.4 dex); (3) we recover no evolution of the Fe II/Mg II abundance ratio with cosmic time; and (4) we derive near-zone sizes and, together with measurements for z similar to 6 quasars from recent work, confirm a shallow evolution of the decreasing quasar near-zone sizes with redshift. Finally, we present new millimeter observations of the [C II] 158 mu m emission line and underlying dust continuum from NOEMA for four quasars and provide new accurate redshifts and [C II]/infrared luminosity estimates. The analysis presented here shows the large range of properties of the most distant quasars.ERC grant "Cosmic Dawn"; DFG [1573]; National Aeronautics and Space Administration through the Planetary Science Division of the NASA Science Mission Directorate [NNX08AR22G]; National Science Foundation [AST-1238877]; ESO Telescopes at the La Silla Paranal Observatory [092.A-0339(A), 092.A-0150(A), 092.A-0150(B), 093.A-0863(A), 095.A-9001(A), 095.A-0375(A), 095.A-0535(A), 095.A-0535(B), 096.A-0420(A), 096.A-9001(A), 097.A-9001(A), 097.A-0094(A), 097.A-0094(B)]; Leibniz Prize (DFG grant) [HA 1850/28-1]; W. M. Keck Foundation; NFS [AST-1109915]; NSF Telescope System Instrumentation Program (TSIP); Ohio Board of Regents; Ohio State University Office of Research; NSF [AST-9987045]; INSU/CNRS (France); MPG (Germany); IGN (Spain); National Aeronautics and Space AdministrationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu