TY - JOUR
T1 - Discovery of 16 New z ∼ 5.5 Quasars
T2 - Filling in the Redshift Gap of Quasar Color Selection
AU - Yang, Jinyi
AU - Fan, Xiaohui
AU - Wu, Xue Bing
AU - Wang, Feige
AU - Bian, Fuyan
AU - Yang, Qian
AU - McGreer, Ian D.
AU - Yi, Weimin
AU - Jiang, Linhua
AU - Green, Richard
AU - Yue, Minghao
AU - Wang, Shu
AU - Li, Zefeng
AU - Ding, Jiani
AU - Dye, Simon
AU - Lawrence, Andy
N1 - Funding Information:
J. Yang, X.-B. Wu, and F. Wang acknowledge the support from NSFC grant no. 11373008 and 11533001, the Strategic Priority Research Program The Emergence of Cosmological Structures of the Chinese Academy of Sciences, grant no. XDB09000000, the National Key Basic Research Program of China 2014CB845700, and the Ministry of Science and Technology of China under grant 2016YFA0400703. J. Yang, X. Fan, and I. D. McGreer acknowledge the support from the U.S. NSF grant AST 11-07682 and AST 15-15115. Funding for the Lijiang 2.4 m telescope is provided by the Chinese Academy of Sciences and the People's Government of Yunnan Province.
Publisher Copyright:
© 2017. The American Astronomical Society. All rights reserved.
PY - 2017/4
Y1 - 2017/4
N2 - We present initial results from the first systematic survey of luminous z ∼ 5.5 quasars. Quasars at z ∼ 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 ∼ 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 ∼ 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 ∼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 ∼ 5.5 quasar.
AB - We present initial results from the first systematic survey of luminous z ∼ 5.5 quasars. Quasars at z ∼ 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 ∼ 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 ∼ 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 ∼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 ∼ 5.5 quasar.
KW - galaxies: active
KW - galaxies: high-redshift
KW - quasars: emission lines
KW - quasars: general
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U2 - 10.3847/1538-3881/aa6577
DO - 10.3847/1538-3881/aa6577
M3 - Article
AN - SCOPUS:85017290673
SN - 0004-6256
VL - 153
JO - Astronomical Journal
JF - Astronomical Journal
IS - 4
M1 - 184
ER -