Deep CFHT Y-band Imaging of VVDS-F22 Field. II. Quasar Selection and Quasar Luminosity Function

Jinyi Yang, Xue Bing Wu, Dezi Liu, Xiaohui Fan, Qian Yang, Feige Wang, Ian D. McGreer, Zuhui Fan, Shuo Yuan, Huanyuan Shan

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Abstract

We report the results of a faint quasar survey in a one-square-degree field. The aim is to test the Y - K g - z and J - K i - Y color selection criteria for quasars at faint magnitudes to obtain a complete sample of quasars based on deep optical and near-infrared color-color selection and to measure the faint end of the quasar luminosity function (QLF) over a wide redshift range. We carried out a quasar survey based on the Y - K g - z and J - K i - Y quasar selection criteria, using the deep Y-band data obtained from our CFHT/WIRCam Y-band images in a two-degree field within the F22 field of the VIMOS VLT deep survey, optical co-added data from Sloan Digital Sky Survey Stripe 82 and deep near-infrared data from the UKIDSS Deep Extragalactic Survey in the same field. We discovered 25 new quasars at 0.5 < z < 4.5 and i < 22.5 mag within one-square-degree field. The survey significantly increases the number of faint quasars in this field, especially at z ∼ 2-3. It confirms that our color selections are highly complete in a wide redshift range (z < 4.5), especially over the quasar number density peak at z ∼ 2-3, even for faint quasars. Combining all previous known quasars and new discoveries, we construct a sample with 109 quasars and measure the binned QLF and parametric QLF. Although the sample is small, our results agree with a pure luminosity evolution at lower redshift and luminosity evolution and density evolution model at redshift z > 2.5.

Original languageEnglish (US)
Article number110
JournalAstronomical Journal
Volume155
Issue number3
DOIs
Publication statusPublished - Mar 1 2018

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Keywords

  • galaxies: active
  • galaxies: high-redshift
  • quasars: emission lines
  • quasars: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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