Discovery of 16 New z ∼ 5.5 Quasars: Filling in the Redshift Gap of Quasar Color Selection
McGreer, Ian D.
AffiliationUniv Arizona, Steward Observ
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PublisherIOP PUBLISHING LTD
CitationDiscovery of 16 New z ∼ 5.5 Quasars: Filling in the Redshift Gap of Quasar Color Selection 2017, 153 (4):184 The Astronomical Journal
JournalThe Astronomical Journal
Rights© 2017. The American Astronomical Society. All rights reserved.
Collection InformationThis 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 email@example.com.
AbstractWe present initial results from the first systematic survey of luminous z similar to 5.5 quasars. Quasars at z similar to 5.5, the post-reionization epoch, are crucial tools to explore the evolution of intergalactic medium, quasar evolution, and the early super-massive black hole growth. However, it has been very challenging to select quasars at redshifts 5.3 <= z <= 5.7 using conventional color selections, due to their similar optical colors to late-type stars, especially M dwarfs, resulting in a glaring redshift gap in quasar redshift distributions. We develop a new selection technique for z similar to 5.5 quasars based on optical, near-IR, and mid-IR photometric data from Sloan Digital Sky Survey (SDSS), UKIRT InfraRed Deep Sky Surveys-Large Area Survey (ULAS), VISTA Hemisphere Survey (VHS), and Wide Field Infrared Survey Explorer. From our pilot observations in the SDSS-ULAS/VHS area, we have discovered 15 new quasars at 5.3. z. 5.7 and 6 new lower redshift quasars, with SDSS z band magnitude brighter than 20.5. Including other two z similar to 5.5 quasars already published in our previous work, we now construct a uniform quasar sample at 5.3 <= z <= 5.7, with 17 quasars in a similar to 4800 square degree survey area. For further application in a larger survey area, we apply our selection pipeline to do a test selection by using the new wide field J-band photometric data from a preliminary version of the UKIRT Hemisphere Survey (UHS). We successfully discover the first UHS selected z similar to 5.5 quasar.
VersionFinal published version
SponsorsNSFC [11373008, 11533001]; Strategic Priority Research Program "The Emergence of Cosmological Structures" of the Chinese Academy of Sciences [XDB09000000]; National Key Basic Research Program of China [2014CB845700]; Ministry of Science and Technology of China [2016YFA0400703]; U.S. NSF [AST 11-07682, AST 15-15115]; Chinese Academy of Sciences; People's Government of Yunnan Province; Strategic Priority Research Program "The Emergence of Cosmological Structures" [XDB09000000]; National Astronomical Observatories; Special Fund for Astronomy from the Ministry of Finance in China; Open Project Program of the Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences; Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy Office of Science; University of Arizona; Brazilian Participation Group; Brookhaven National Laboratory; University of Cambridge; Carnegie Mellon University; University of Florida; French Participation Group; German Participation Group; Harvard University; Instituto de Astrofisica de Canarias; Michigan State/Notre Dame/JINA Participation Group; Johns Hopkins University; Lawrence Berkeley National Laboratory; Max Planck Institute for Astrophysics; Max Planck Institute for Extraterrestrial Physics; New Mexico State University; New York University; Ohio State University; Pennsylvania State University; University of Portsmouth; Princeton University; Spanish Participation Group; University of Tokyo; University of Utah; Vanderbilt University; University of Virginia; University of Washington; Yale University; National Aeronautics and Space Administration