J/ApJ/815/91 z<0.16 CIV absorbers from HST/COS QSOs spectra (Burchett+, 2015)
A deep search for faint galaxies associated with very low-redshift
C IV absorbers.
II. Program design, absorption-line measurements, and absorber statistics.
Burchett J.N., Tripp T.M., Prochaska J.X., Werk J.K., Tumlinson J.,
O'Meara J.M., Bordoloi R., Katz N., Willmer C.N.A.
<Astrophys. J., 815, 91 (2015)>
=2015ApJ...815...91B 2015ApJ...815...91B (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Spectra, ultraviolet ; Redshifts ; Line Profiles
Keywords: galaxies: dwarf; galaxies: evolution; galaxies: halos;
intergalactic medium; quasars: absorption lines
Abstract:
To investigate the evolution of metal-enriched gas over recent cosmic
epochs as well as to characterize the diffuse, ionized, metal-enriched
circumgalactic medium, we have conducted a blind survey for CIV
absorption systems in 89 QSO sightlines observed with the Hubble Space
Telescope Cosmic Origins Spectrograph. We have identified 42 absorbers
at z<0.16, comprising the largest uniform blind sample size to date in
this redshift range. Our measurements indicate an increasing CIV
absorber number density per comoving path length (dN/dX=7.5±1.1) and
modestly increasing mass density relative to the critical density of
the universe (ΩCIV=10.0±1.5x10-8) from z∼1.5 to the
present epoch, consistent with predictions from cosmological
hydrodynamical simulations. Furthermore, the data support a functional
form for the column density distribution function that deviates from a
single power law, also consistent with independent theoretical
predictions. As the data also probe heavy element ions in addition to
CIV at the same redshifts, we identify, measure, and search for
correlations between column densities of these species where
components appear to be aligned in velocity. Among these ion-ion
correlations, we find evidence for tight correlations between CII and
SiII, CII and SiIII, and CIV and SiIV, suggesting that these pairs of
species arise in similar ionization conditions. However, the evidence
for correlations decreases as the difference in ionization potential
increases. Finally, when controlling for observational bias, we find
only marginal evidence for a correlation (86.8% likelihood) between
the Doppler line width b(CIV) and column density N(CIV).
Description:
Our CIV sample is composed of systems detected in 89 sightlines
targeted by three HST programs using the Cosmic Origins Spectrograph
(COS): COS-Halos (Werk et al. 2012ApJS..198....3W 2012ApJS..198....3W; Tumlinson et al.
2013ApJ...777...59T 2013ApJ...777...59T), COS-Dwarfs (Bordoloi et al.
2014ApJ...796..136B 2014ApJ...796..136B), and the COS Absorption Survey of Baryon Harbors
(CASBaH, Tripp et al. 2011Sci...334..952T 2011Sci...334..952T; Meiring et al.
2013ApJ...767...49M 2013ApJ...767...49M). All of these data use the G130M and G160M
gratings, covering the wavelength range 1100-1800Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 64 89 QSO sample for C IV survey
table2.dat 108 206 Voigt profile fitting measurements by absorber
component
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See also:
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
J/A+A/583/A75 : Large Quasar Astrometric Catalogue 3 (LQAC-3) (Souchay+, 2015)
J/ApJ/814/40 : Nearby galaxy filaments with UV obs. (Wakker+, 2015)
J/ApJS/210/7 : BOSS narrow CIV absorption lines. I. zem≤2.4 (Chen+, 2014)
J/MNRAS/435/1198 : z∼6 QSOs CIV doublet absorption systems (D'Odorico+, 2013)
J/ApJ/777/168 : CIV & SiIV broad absorption line troughs in SDSS (Filiz+, 2013)
J/ApJ/763/37 : Metals in SDSS QSOs I. 1.5<z<4.5 CIV absorbers (Cooksey+, 2013)
J/ApJ/759/112 : The UV low-redshift intergalactic medium (Tilton+, 2012)
J/ApJ/740/91 : Lyα and OVI in galaxies around quasars (Prochaska+, 2011)
J/ApJ/729/87 : SiIV absorption systems (Cooksey+, 2011)
J/MNRAS/401/2715 : CIV column densities in z<2.5 QSOs (D'odorico+, 2010)
J/ApJ/708/868 : CIV candidates (Cooksey+, 2010)
J/ApJS/177/39 : Survey of low-redshift OVI absorbers (Tripp+, 2008)
J/ApJ/641/78 : CIV variability in 105 SDSS quasars (Wilhite+, 2006)
J/ApJ/596/768 : Optical depths in 19 QSOs (Schaye+, 2003)
J/A+A/283/759 : CIV QSO absorption systems (Petitjean+ 1994)
http://www.nist.gov/pml/data/asd.cfm : NIST atomic spectra database
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- Name QSO identifier
26- 33 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000)
35- 42 F8.4 deg DEdeg Declination in decimal degrees (J2000)
44- 48 F5.3 --- zqso [0.06/1.5] QSO spectroscopic redshift
50- 64 A15 --- QSO Abbreviated QSO identifier as in table 2;
column added by CDS
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- QSO QSO identifier
17- 23 F7.5 --- zabs [0.002/0.2] Absorption line derived redshift
25- 30 A6 --- Ion Ion identifier
32 A1 --- f_Ion [ab] Flag on Ion (1)
34- 71 A38 0.1nm Lines Lines in profile fit in Angstroms
73 A1 --- l_logN Limit flag on logN (2)
74- 80 F7.2 [cm-2] logN [12.4/20.8]?=9999 Log column density of Ion
82- 88 F7.2 [cm-2] e_logN [0.01/2.4]?=9999 Uncertainty in logN
90- 93 I4 km/s b [6/126]?=9999 Doppler b-value parameter
95- 98 I4 km/s e_b [0/27]?=9999 Uncertainty in b
100-103 I4 km/s v [-177/214]?=9999 Velocity centroid
105-108 I4 km/s e_v [1/68]?=9999 Uncertainty in v
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Note (1): Flag on Ion as follows:
a = Measurements shown with errors from Voigt profile fitting but may
suffer from saturation.
b = The presence of the line is apparent but either telluric emission or
bad pixels prevent a measurement.
Note (2): Column densities expressed as lower limits were measured using the
apparent optical method (Savage & Sembach 1991ApJ...379..245S 1991ApJ...379..245S).
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History:
From electronic version of the journal
References:
Burchett et al. Paper I. 2013ApJ...779L..17B 2013ApJ...779L..17B
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 08-Mar-2016