J/AJ/155/110 Deep CFHT imaging of VVDS-F22 field. II. Quasars (Yang+, 2018)
Deep CFHT Y-band imaging of VVDS-F22 field.
II. Quasar selection and quasar luminosity function.
Yang J., Wu X.-B., Liu D., Fan X., Yang Q., Wang F., Mcgreer I.D., Fan Z.,
Yuan S., Shan H.
<Astron. J., 155, 110-110 (2018)>
=2018AJ....155..110Y 2018AJ....155..110Y (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Photometry, infrared ; Photometry, SDSS ; Redshifts
Keywords: galaxies: active - galaxies: high-redshift - quasars: emission lines -
quasars: general
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.
Description:
We obtained Y-band imaging of a two-square-degree field (see Figure 1)
within F22 field of the VVDS using CFHT WIRCam in 2012 August, September,
and October. The WIRCam focal plane is made of a mosaic that includes
four HAWAII2-RG detectors. The field of view of the full mosaic is
21.5'x21.5'. We divided our two-square-degree field into 18 sub-fields,
each of 20'x20', as shown in Figure 1. The final imaged area is about
128'x65', fully covering those 18 sub-fields.
Our quasars candidates were observed by MMT/Hectospec (Fabricant et al.
2005PASP..117.1411F 2005PASP..117.1411F). We divided our two-square-degree field into two
one-square-degree fields to match the Hectospec focus plane. Our
spectroscopically identifications have been done on 2013 October 8, 9 and
November 29 with MMT Hectospec in a one-square-degree field
(334.5°<RA<335.47°). In this one-square-degree field, 143 quasar
candidates had been observed. Candidates in the other one-square-degree
field were not observed due to the limited observing time. The effective
exposure time for final identification is 3x30 minutes in total with
an average seeing ∼0.52".
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 115 109 Quasar sample in the one-square-degree field
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See also:
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
VII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012)
III/269 : VIMOS VLT Deep Survey (VVDS) (Le Fevre+, 2013)
VII/270 : SDSS quasar catalog: tenth data release (Paris+, 2014)
VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)
J/MNRAS/386/1605 : Luminous K-band selected QSOs from UKIDSS (Maddox+, 2008)
J/MNRAS/406/1583 : Quasar from SDSS and UKIDSS (Wu+, 2010)
J/AJ/142/78 : New 2.2<z<3 quasars from SDSS and UKIDSS (Wu+, 2011)
J/ApJ/768/105 : z∼5 QSO luminosity function from SDSS Stripe 82
(McGreer+, 2013)
J/AJ/154/269 : A new photo-z method for quasars in Stripe 82 (Yang+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- QSO Quasar name (JHHMMSS.ss+DDMMSS.ss)
22- 26 F5.3 --- z [0.521/4.22] Redshift
28- 36 A9 --- r_z Reference for z (SDSS, VVDS or This work)
38- 43 F6.2 mag 1450Mag [-27/-20.07] Absolute AB magnitude at
the rest-frame 1450 Å
45- 49 F5.2 mag gmag [17.36/23.31] SDSS g band magnitude
51- 55 F5.3 mag e_gmag [0.001/0.075] Uncertainty in gmag
57- 61 F5.2 mag imag [17.26/22.34] SDSS i band magnitude
63- 67 F5.3 mag e_imag [0.001/0.96] Uncertainty in imag
69- 73 F5.2 mag zmag [17.34/22.36] SDSS z band magnitude
75- 79 F5.3 mag e_zmag [0.003/0.285] Uncertainty in zmag
81- 85 F5.2 mag Ymag [17/21.63] CFHT/WIRCam Y band Vega magnitude
87- 91 F5.3 mag e_Ymag [0.003/0.089] Uncertainty in Ymag
93- 97 F5.2 mag Jmag [16.69/21.16] UKIDSS J band Vega magnitude
99-103 F5.3 mag e_Jmag [0.005/0.077] Uncertainty in Jmag
105-109 F5.2 mag Kmag [15.74/19.98] UKIDSS K band Vega magnitude
111-115 F5.3 mag e_Kmag [0.004/0.082] Uncertainty in Kmag
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History:
From electronic version of the journal
References:
Liu et al. Paper I. 2017AJ....153...53L 2017AJ....153...53L
(End) Tiphaine Pouvreau [CDS] 25-Oct-2018