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Title: Discovery of 16 New z  ∼ 5.5 Quasars: Filling in the Redshift Gap of Quasar Color Selection

Abstract

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 applicationmore » 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.« less

Authors:
; ; ; ; ; ;  [1]; ;  [2];  [3]; ; ;  [4];  [5];  [6];  [7]
  1. Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China)
  2. Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)
  3. Research School of Astronomy and Astrophysics, Australian National University, Weston Creek, ACT 2611 (Australia)
  4. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
  5. Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China)
  6. School of Physics and Astronomy, Nottingham University, University Park, Nottingham, NG7 2RD (United Kingdom)
  7. Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom)
Publication Date:
OSTI Identifier:
22663720
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 153; Journal Issue: 4; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; COLOR; DWARF STARS; EMISSION; GALAXIES; INFRARED SURVEYS; INTERGALACTIC SPACE; PHOTOMETRY; QUASARS; RED SHIFT; SKY; STAR EVOLUTION

Citation Formats

Yang, Jinyi, Wu, Xue-Bing, Wang, Feige, Yang, Qian, Yue, Minghao, Wang, Shu, Li, Zefeng, Fan, Xiaohui, Jiang, Linhua, Bian, Fuyan, McGreer, Ian D., Green, Richard, Ding, Jiani, Yi, Weimin, Dye, Simon, and Lawrence, Andy. Discovery of 16 New z  ∼ 5.5 Quasars: Filling in the Redshift Gap of Quasar Color Selection. United States: N. p., 2017. Web. doi:10.3847/1538-3881/AA6577.
Yang, Jinyi, Wu, Xue-Bing, Wang, Feige, Yang, Qian, Yue, Minghao, Wang, Shu, Li, Zefeng, Fan, Xiaohui, Jiang, Linhua, Bian, Fuyan, McGreer, Ian D., Green, Richard, Ding, Jiani, Yi, Weimin, Dye, Simon, & Lawrence, Andy. Discovery of 16 New z  ∼ 5.5 Quasars: Filling in the Redshift Gap of Quasar Color Selection. United States. doi:10.3847/1538-3881/AA6577.
Yang, Jinyi, Wu, Xue-Bing, Wang, Feige, Yang, Qian, Yue, Minghao, Wang, Shu, Li, Zefeng, Fan, Xiaohui, Jiang, Linhua, Bian, Fuyan, McGreer, Ian D., Green, Richard, Ding, Jiani, Yi, Weimin, Dye, Simon, and Lawrence, Andy. Sat . "Discovery of 16 New z  ∼ 5.5 Quasars: Filling in the Redshift Gap of Quasar Color Selection". United States. doi:10.3847/1538-3881/AA6577.
@article{osti_22663720,
title = {Discovery of 16 New z  ∼ 5.5 Quasars: Filling in the Redshift Gap of Quasar Color Selection},
author = {Yang, Jinyi and Wu, Xue-Bing and Wang, Feige and Yang, Qian and Yue, Minghao and Wang, Shu and Li, Zefeng and Fan, Xiaohui and Jiang, Linhua and Bian, Fuyan and McGreer, Ian D. and Green, Richard and Ding, Jiani and Yi, Weimin and Dye, Simon and Lawrence, Andy},
abstractNote = {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.},
doi = {10.3847/1538-3881/AA6577},
journal = {Astronomical Journal (Online)},
number = 4,
volume = 153,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}