J/ApJS/265/46 SDSS DR16Q QSO pairs with MgII abs. line analysis (Chen+, 2023)
The study of the circumgalactic medium with quasar pairs.
Chen Z.-F., Qin H.-C., Cai J.-T., Zhou Y.-T., Chen Z.-G., Pang T.-T.,
Wang Z.-W., Cheng K.-F.
<Astrophys. J. Suppl. Ser., 265, 46 (2023)>
=2023ApJS..265...46C 2023ApJS..265...46C
ADC_Keywords: QSOs; Spectra, optical; Redshifts; Equivalent widths; Surveys
Keywords: Quasar absorption line spectroscopy ; Quasar-galaxy pairs
Abstract:
We have collected 10025 foreground-background quasar pairs with
projected distances dp<500kpc from the large quasar catalog of the
Sloan Digital Sky Survey DR16Q. We investigate the properties of the
MgII absorption lines with Wr>0.15Å around foreground quasars,
including both the line of sight (LOS; of foreground quasars) and
transverse (TRA; perpendicular to the LOS) absorptions. Both the
equivalent width (the correlation coefficient ρ=-0.915 and the
probability P<10-4 of no correlation) and incident rate
(ρ=-0.964 and P<10-6) of TRA MgII absorption lines are obviously
anticorrelated with projected distance. The incident rate of TRA MgII
absorption lines is obviously (>4σ) greater than that of LOS
MgII absorption lines at projected distances dp<200kpc, while the
TRA and LOS MgII both have similar (<3σ) incident rates at
scales dp>200kpc. The anisotropic radiation from quasars would be
the most possible interpretation for the anisotropic absorption around
quasars. This could also indicate that the quasar radiation is not
obviously impacting the gas halos of quasars at scales dp>200kpc.
Description:
The Sloan Digital Sky Survey (SDSS) is an ambitious project to image
the sky using a dedicated 2.5m wide-field telescope located at Apache
Point Observatory in New Mexico, United States. During the first and
second stages (SDSS-I/II, from 2000 to 2008), the SDSS obtained quasar
spectra in a coverage wavelength from 3800 to 9200Å with R∼2000.
During the third and fourth stages (SDSS-III/IV, from 2008 to 2020),
the SDSS gathered quasar spectra in a coverage wavelength from 3600 to
10500Å at a resolution of R∼1300-2500. The Sixteenth Data Release
is the final data set for the SDSS-IV quasar catalog (DR16Q;
Lyke+ 2020, VII/289), which includes 750,414 quasars that are
accumulated from SDSS-I to SDSS-IV. Using the quasar spectra from
DR16Q, we construct a large sample of quasar pairs to investigate the
properties of MgIIλλ2796,2803 absorption lines around
foreground quasars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 107 10033 The properties of the quasar pairs and the
line of sight (LOS) MgII absorption lines
table2.dat 81 10035 The background quasars with transverse (TRA)
MgII absorption lines
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
VII/289 : SDSS quasar catalog, sixteenth data release (DR16Q) (Lyke+, 2020)
J/ApJ/651/61 : Opt. thick absorbers near luminous quasars (Hennawi+, 2006)
J/ApJ/639/766 : SDSS-DR3 strong MgII absorbers (Prochter+, 2006)
J/MNRAS/392/1539 : Metal absorption systems in pairs of QSOs (Tytler+, 2009)
J/ApJ/714/1521 : Spectroscopy of galaxies around distant QSOs (Chen+, 2010)
J/ApJ/724/L176 : MgII absorbing gas around galaxies (Chen+, 2010)
J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJ/761/112 : High-z MgII absorption QSOs with FIRE (Matejek+, 2012)
J/ApJ/748/131 : MgII absorbers in SDSS-DR7 quasar catalog (Shen+, 2012)
J/ApJ/763/37 : Metals in SDSS QSOs. I. 1.5<z<4.5 CIV abs. (Cooksey+, 2013)
J/ApJ/776/136 : QPQ VI. HI absorption of z∼2 quasars (Prochaska+, 2013)
J/ApJ/762/L19 : Quasar pairs spectroscopy (Prochaska+, 2013)
J/ApJ/796/140 : Circumgalactic medium around z∼2 QSOs (Prochaska+, 2014)
J/ApJS/221/32 : Narrow MgII absorption lines from SDSS-DR9Q (Chen+, 2015)
J/MNRAS/452/2553 : Sample of foreground-background QSO pairs (Johnson+, 2015)
J/MNRAS/462/2980 : BOSS narrow CIV absorption lines. III. (Chen+, 2016)
J/ApJ/817/55 : NIR spectroscopy of 1.5<z<3.5 broad-band QSOs (Shen, 2016)
J/ApJS/235/11 : Absorption features in SDSS. I. MgII doublets (Chen+, 2018)
J/ApJS/239/23 : CIV NAL systems from SDSS-DR14 quasar spectra (Chen+, 2018)
J/ApJS/244/36 : QSO properties from SDSS. II. First two years (Chen+, 2019)
J/ApJ/887/196 : REQUIEM survey. I. Lya halos around QSOs (Farina+, 2019)
J/MNRAS/490/1451 : MUDF data of galaxy groups at 0.5<z<1.5 (Fossati+, 2019)
J/ApJ/884/151 : Lyman cont. luminosity of SDSS QSOs at z∼3 (Jalan+, 2019)
J/ApJS/250/3 : Variable MgII NALs in SDSS DR14 (Chen+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Pair [1/10033] Pair identifier
7- 24 A18 --- fSDSS Foreground SDSS identifier
26- 30 I5 --- Plate [273/11704] SDSS Plate identifier
32- 36 I5 d MJD [51609/58543] SDSS Modified Julian Date
of observation
38- 41 I4 --- Fiber [1/1000] SDSS Fiber identifier
43- 48 F6.4 --- zEm [0.4/2.51] Redshift from emission lines
50- 55 F6.3 [10-7W] logLBol [44.22/47.56] log bolometric luminosity
57- 61 F5.1 kpc Dist [20/500] Distance
63- 68 F6.4 --- zAbs [0.4/2.3]? Redshift from absorption lines (G1)
70- 73 F4.2 0.1nm EW2798 [0.14/9]? MgII2798Å equivalent width;
Angstroms (G1)
75- 78 F4.2 0.1nm e_EW2798 [0.02/1.4] 1σ uncertainty in EW2798 (G1)
80- 83 F4.2 0.1nm EW2803 [0.08/6.9]? MgII2803Å equivalent width;
Angstroms (G1)
85- 88 F4.2 0.1nm e_EW2803 [0.02/1.4] 1σ uncertainty in EW2803 (G1)
90-107 A18 --- bSDSS Background SDSS identifier
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Pair [1/10035] Pair identifier
7- 24 A18 --- bSDSS Background SDSS identifier
26- 30 I5 --- Plate [274/11704] SDSS Plate identifier
32- 36 I5 d MJD [51662/58543] SDSS Modified Julian Date of
observation
38- 41 I4 --- Fiber [1/1000] SDSS Fiber identifier
43- 48 F6.4 --- zEm [0.5/5.1] Redshift from emission lines
50- 54 F5.1 kpc Dist [20/500] Distance
56- 61 F6.4 --- zAbs [0.4/2.5]? Redshift from absorption lines (G1)
63- 66 F4.2 0.1nm EW2798 [0.17/5.13]? MgII2798Å equivalent width;
Angstroms (G1)
68- 71 F4.2 0.1nm e_EW2798 [0.01/1.2] 1σ uncertainty in EW2798 (G1)
73- 76 F4.2 0.1nm EW2803 [0.06/4.7]? MgII2803Å equivalent width;
Angstroms (G1)
78- 81 F4.2 0.1nm e_EW2803 [0.01/1.4] 1σ uncertainty in EW2803 (G1)
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Global notes:
Note (G1): A blank indicates spectra without detected MgII absorption lines.
Only the equivalent width of 1σ upper limit is provided for
the spectra without detected MgII absorption lines.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-May-2023