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The Pan-STARRS1 Distant z > 5.6 Quasar Survey: More than 100 Quasars within the First Gyr of the Universe

Bañados, E. and Baloković, M. (2016) The Pan-STARRS1 Distant z > 5.6 Quasar Survey: More than 100 Quasars within the First Gyr of the Universe. Astrophysical Journal Supplement Series, 227 (1). Art. No. 11. ISSN 0067-0049.

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Luminous quasars at z > 5.6 can be studied in detail with the current generation of telescopes and provide us with unique information on the first gigayear of the universe. Thus far, these studies have been statistically limited by the number of quasars known at these redshifts. Such quasars are rare, and therefore, wide-field surveys are required to identify them, and multiwavelength data are required to separate them efficiently from their main contaminants, the far more numerous cool dwarfs. In this paper, we update and extend the selection for the z ~ 6 quasars presented in Bañados et al. (2014) using the Pan-STARRS1 (PS1) survey. We present the PS1 distant quasar sample, which currently consists of 124 quasars in the redshift range 5.6 ≾ z ≾ 6.7 that satisfy our selection criteria. Of these quasars, 77 have been discovered with PS1, and 63 of them are newly identified in this paper. We present the composite spectra of the PS1 distant quasar sample. This sample spans a factor of ~20 in luminosity and shows a variety of emission line properties. The number of quasars at z > 5.6 presented in this work almost doubles the previously known quasars at these redshifts, marking a transition phase from studies of individual sources to statistical studies of the high-redshift quasar population, which was impossible with earlier, smaller samples.

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URLURL TypeDescription Paper
Bañados, E.0000-0002-2931-7824
Baloković, M.0000-0003-0476-6647
Additional Information:© 2016 The American Astronomical Society. Received 2016 May 27; revised 2016 July 25; accepted 2016 August 3; published 2016 November 14. We acknowledge the assistance of the following people in some of the observations presented herein: Roberto Assef, Carla Fuentes, David Girou, Fiona Harrison, Bing Jiang, George Lansbury, Elena Manjavacas, Alejandra Melo, Gaël Noirot, Michael Rauch, and Eden Stern. We also thank Carlos Contreras for his help with the data reduction of the near-infrared images taken with Retrocam at the du Pont Telescope. EPF and BPV acknowledge funding through the ERC grant "Cosmic Dawn." XF, IM, and JTS acknowledge support from NSF grants AST 11-07682 and AST 15-15115. ES acknowledges support for this work provided by NASA through Hubble Fellowship grant HST-HF2-51367.001-A, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. The Pan-STARRS1 Surveys (PS1) have been made possible through contributions of the Institute for Astronomy, University of Hawaii; the Pan-STARRS Project Office; the Max Planck Society and its participating institutes (the Max Planck Institute for Astronomy, Heidelberg, and the Max Planck Institute for Extraterrestrial Physics, Garching); the Johns Hopkins University; Durham University; the University of Edinburgh; Queen's University Belfast; the Harvard–Smithsonian Center for Astrophysics; the Las Cumbres Observatory Global Telescope Network, Incorporated; the National Central University of Taiwan; the Space Telescope Science Institute; the National Aeronautics and Space Administration (under Grant No. NNX08AR22G, issued through the Planetary Science Division of the NASA Science Mission Directorate); the National Science Foundation (under Grant No. AST-1238877); the University of Maryland; and Eotvos Lorand University. This work is based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programs 091.A-0421, 092.A-0150, 092.A-0339, 093.A-0574, 093.A-0863, 094.A-0053, 094.A-0079, 095.A-0375, 095.A-0535, 096.A-0291, 096.A-0420, 381.A-0486, and ID 179.A-2010 (PI. McMahon). This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile. The FIRE observations were supported by the NSF under grant AST-1109915. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership between the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize the very significant cultural role that the summit of Mauna Kea has always had within the indigenous Hawaiian community, who hold this feature in deep reverence. We are most fortunate to have the opportunity to conduct observations from this mountain. Part of our data is based on observations collected at the Centro Astronómico Hispano Alemán at Calar Alto, jointly operated by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía. Some of the observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution. The LBT is an international collaboration among institutions in the United States, Italy, and Germany. The LBT Corporation partners are the University of Arizona, on behalf of the Arizona University System; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; the Ohio State University; and Research Corporation, on behalf of the University of Notre Dame, the University of Minnesota, and the University of Virginia. This paper used data obtained with the MODS spectrograph, built with funding from NSF grant AST-9987045 and the NSF Telescope System Instrumentation Program and with additional funds from the Ohio Board of Regents and the Ohio State University Office of Research. Part of the funding for GROND (both hardware and personnel) was generously granted from the Leibniz Prize to Prof. G. Hasinger (DFG grant HA 1850/28-1). UKIDSS and UHS use the UKIRT Wide Field Camera (Casali et al. 2007) and the photometric system described in Hewett et al. (2006). The science archive is described in Hambly et al. (2008). This publication makes use of data products from the Wide-Field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research has benefitted from the SpeX Prism Spectral Libraries, maintained by Adam Burgasser at This research made use of Astropy, a community-developed core Python package for astronomy (Astropy Collaboration et al. 2013, The plots in this publication were produced using Matplotlib (Hunter 2007, Facilities: PS1 (GPC1) - , VLT:Antu (FORS2) - , NTT (EFOSC2) - , LBT (MODS) - , Max Planck:2.2m (GROND) - , Magellan:Baade (FIRE) - , Magellan:Clay (LDSS3) - , Keck:I (LRIS) - , Hale (DBSP) - , CAO:3.5 m (Omega2000) - , CAO:2.2 m (CAFOS) - , MMT (SWIRC) - , Du Pont (Retrocam).
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
European Research Council (ERC)Cosmic Dawn
NASA Hubble FellowshipHST-HF2-51367.001-A
NASANAS 5-26555
W. M. Keck FoundationUNSPECIFIED
Ohio Board of RegentsUNSPECIFIED
Ohio State UniversityUNSPECIFIED
Deutsche Forschungsgemeinschaft (DFG)HA 1850/28-1
Subject Keywords:cosmology: observations – quasars: emission lines – quasars: general
Issue or Number:1
Record Number:CaltechAUTHORS:20161118-074811956
Persistent URL:
Official Citation:E. Bañados et al 2016 ApJS 227 11
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:72148
Deposited By: Tony Diaz
Deposited On:18 Nov 2016 17:03
Last Modified:20 Dec 2019 17:10

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