Discovery of eight z ∼ 6 quasars in the Sloan Digital Sky Survey overlap regions

Journal Article · Mon Jun 01 04:00:00 EDT 2015 · The Astronomical Journal (Online)

DOI:https://doi.org/10.1088/0004-6256/149/6/188· OSTI ID:22879499

Jiang, Linhua; Wang, Ran ^[1]; McGreer, Ian D.; Fan, Xiaohui; Cai, Zheng; Clément, Benjamin ^[2]; Bian, Fuyan ^[3]; Fan, Zhou ^[4]

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1. Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)
2. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
3. Research School of Astronomy and Astrophysics, Australian National University, Weston Creek, ACT 2611 (Australia)
4. Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

We present the discovery of eight quasars at z∼6 identified in the Sloan Digital Sky Survey (SDSS) overlap regions. Individual SDSS imaging runs have some overlap with each other, leading to repeat observations over an area spanning >4000 deg{sup 2} (more than one-fourth of the total footprint). These overlap regions provide a unique data set that allows us to select high-redshift quasars more than 0.5 mag fainter in the z band than those found with the SDSS single-epoch data. Our quasar candidates were first selected as i-band dropout objects in the SDSS imaging database. We then carried out a series of follow-up observations in the optical and near-IR to improve photometry, remove contaminants, and identify quasars. The eight quasars reported here were discovered in a pilot study utilizing the overlap regions at high galactic latitude (|b|>30{sup ∘}). These quasars span a redshift range of 5.86

• OSTI ID: 22879499
• Journal Information: The Astronomical Journal (Online), Journal Name: The Astronomical Journal (Online) Journal Issue: 6 Vol. 149; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMOLOGY
IMAGES
PHOTOMETRY
QUASARS
RED SHIFT
TELESCOPES