J/ApJ/763/37 Metals in SDSS QSOs. I. 1.5<z<4.5 CIV absorbers (Cooksey+, 2013)
Precious metals in SDSS quasar spectra.
I. Tracking the evolution of strong, 1.5<z<4.5 C IV absorbers with thousands
of systems.
Cooksey K.L., Kao M.M., Simcoe R.A., O'Meara J.M., Prochaska J.X.
<Astrophys. J., 763, 37 (2013)>
=2013ApJ...763...37C 2013ApJ...763...37C
ADC_Keywords: QSOs ; Redshifts ; Equivalent widths
Keywords: galaxies: halos; intergalactic medium; quasars: absorption lines;
techniques: spectroscopic
Abstract:
We have vastly increased the CIV statistics at intermediate redshift
by surveying the thousands of quasars in the Sloan Digital Sky Survey
(SDSS) Data-Release 7. We visually verified over 16000 CIV systems
with 1.46<z<4.55 - a sample size that renders Poisson error
negligible. Detailed Monte Carlo simulations show that we are
approximately 50% complete down to rest equivalent widths
Wr~0.6Å. We analyzed the sample as a whole and in 10 small
redshift bins with approximately 1500 doublets each. The equivalent
width frequency distributions f(Wr) were well modeled by an
exponential, with little evolution in shape. In contrast with previous
studies that modeled the frequency distribution as a single power law,
the fitted exponential gives a finite mass density for the CIV ions.
The comoving line density dNCIV/dX evolved smoothly with redshift,
increasing by a factor of 2.37±0.09 from z=4.55-1.96, then
plateauing at dNCIV/dX∼0.34 for z=1.96-1.46. Comparing our SDSS
sample with z<1 (ultraviolet) and z>5 (infrared) surveys, we see an
approximately 10-fold increase in dNCIV/dX over z~6->0, for
Wr≥0.6Å. This suggests a monotonic and significant increase in
the enrichment of gas outside galaxies over the 12Gyr lifetime of the
universe.
Description:
SDSS DR7 QSO catalog Schneider et al. (2010, Cat. VII/260; see also
Richards et al. 2002AJ....123.2945R 2002AJ....123.2945R for the SDSS quasar selection)
spectra have wavelength coverage 3820Å≤λ≤9200Å and
resolution varying from R=1850 to 2200 (or 162km/s to 136km/s).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 70 26168 Sightline summary
table3.dat 83 16710 CIV system summary
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See also:
VII/270 : SDSS quasar catalog: tenth data release (Paris+, 2014)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
J/ApJ/761/112 : High-redshift MgII absorption QSOs with FIRE (Matejek+, 2012)
J/ApJ/728/23 : GALEX UV-bright high-redshift quasars (Worseck+, 2011)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJS/193/28 : Galaxy survey around 20 UV-bright quasars (Prochaska+, 2011)
J/AJ/142/122 : SDSS DR7 galaxy/QSOs pairs (Cherinka+, 2011)
J/ApJ/718/392 : SDSS Lyman limit systems at z∼3.5 (Prochaska+, 2010)
J/ApJ/714/1521 : Spectroscopy of galaxies around distant QSOs (Chen+, 2010)
J/ApJ/708/868 : CIV candidates (Cooksey+, 2010)
J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)
J/MNRAS/401/2715 : CIV column densities in z<2.5 QSOs (D'odorico+, 2010)
J/ApJ/699/782 : High-redshift SDSS-DR5 QSOs (Diamond-Stanic+, 2009)
J/ApJ/679/194 : Low-z intergalactic medium. III. (Danforth+, 2008)
J/ApJ/666/757 : CIV 1549Å emission line in AGNs (Sulentic+, 2007)
J/A+A/473/791 : CIV absorption in DLAs and sub-DLAs systems (Fox+, 2007)
J/ApJ/641/78 : CIV variability in 105 SDSS quasars (Wilhite+, 2006)
J/ApJ/639/766 : SDSS-DR3 strong MgII absorbers (Prochter+, 2006)
J/ApJ/635/123 : The SDSS-DR3 damped Lyα survey (Prochaska+, 2005)
J/ApJ/596/768 : Optical depths in 19 QSOs (Schaye+, 2003)
J/A+A/283/759 : CIV QSO absorption systems (Petitjean+ 1994)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- QSO Adopted MJD-plate-fiber QSO identifier (G1)
16- 17 I2 h RAh Hour of Right Ascension (J2000) (G2)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 26 F5.2 s RAs Second of Right Ascension (J2000)
28 A1 --- DE- Sign of the Declination (J2000) (G2)
29- 30 I2 deg DEd Degree of Declination (J2000) (G2)
32- 33 I2 arcmin DEm Arcminute of Declination (J2000)
35- 38 F4.1 arcsec DEs Arcsecond of Declination (J2000)
40- 45 F6.4 --- zQSO [1.7/5.4] QSO redshift (G2)
47- 51 F5.2 pix-1 <S/N> [4/77] Median signal-to-noise in the region
searched for CIV
53- 54 I2 --- f_QSO [0/12] Binary BAL flag (1)
56- 59 F4.2 --- dXmax [0.6/4] Maximum co-moving pathlength available
(2)
61- 62 I2 --- N [0/18] Number of candidate CIV doublets
64 I1 --- NCIV [0/7] Number of confirmed CIV doublets (table3)
66- 70 F5.3 --- dXCIV [0.02/0.42]? Pathlength blocked by
NCIV doublets (2)
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Note (1): Indicates which sightlines were considered BALs by at least one
author (4) and which were confirmed by the authors as BALs to
exclude (8).
Note (2): In the sightline.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 1 I1 --- Code [1/3] System code (1)
3- 16 A14 --- QSO Adopted MJD-plate-fiber QSO identifier (G1)
18- 23 F6.4 --- zQSO [1.7/4.9] QSO redshift (G2)
25- 31 F7.5 --- zCIV [1.4/4.6] CIV-1548Å line redshift
33- 37 F5.3 0.1nm W1548 [0/5.4] Rest equivalent width of 1548 line
39- 43 F5.3 0.1nm e_W1548 [0/1.3] Uncertainty in W1548
45- 49 F5.3 0.1nm W1550 [0/5.6] Rest equivalent width of 1550 line
51- 55 F5.3 0.1nm e_W1550 [0/1.3] Uncertainty in W1550
57- 61 F5.3 --- CW1548 [0/1] Completeness fraction (2)
63- 67 F5.3 --- e_CW1548 [0/0.3] Uncertainty in CW1548
69 A1 --- l_logCIV [<>?] Limit flag on logCIV (3)
71- 75 F5.2 [cm-2] logCIV [12.8/15.5]? Log CIV column density (4)
77- 80 F4.2 [cm-2] e_logCIV [0/1.1] Uncertainty in logCIV
82- 83 I2 --- f_logCIV [1/19] Binary column density flag (5)
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Note (1): Code as follows:
1 = Intervening (δv#1QSO←5000km/s), not in Visual BAL QSO
Sightlines.
2 = Intrinsic (δv#1QSO≥-5000km/s).
3 = In Visual BAL QSO Sightlines.
Note (2): For the doublet from the whole survey average.
Note (3):
> = Upper limit;
< = Lower limit;
? = Lower limit (due to rest equivalent width ratio) and upper limit
(due to low-S/N measurement).
Note (4): This is the combined value from the AODM measurements in both lines.
A blank indicates a "-NaN" value.
Note (5):
1 = good to analyze;
2 = lower limit;
4 = upper limit;
8 = un-weighted average;
16 = default to line value with greater significance.
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Global notes:
Note (G1): From the spectroscopic modified Julian date ("MJD-sp"), plate, and
fiber numbers (see SDSS)
Note (G2): From the DR7 QSO catalog (Schneider et al. 2010, Cat. VII/260).
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History:
From electronic version of the journal
References:
Seyffert et al. Paper II. 2013ApJ...779..161S 2013ApJ...779..161S Cat. J/ApJ/779/161
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 09-Oct-2014