J/MNRAS/456/4488 XQ-100 survey neutral gas (Sanchez-Ramirez+, 2016)
The evolution of neutral gas in damped Lyman α systems from the
XQ-100 survey.
Sanchez-Ramirez R., Ellison S.L., Prochaska J.X., Berg T.A.M., Lopez S.,
D'odorico V., Becker G.D., Christensen L., Cupani G., Denney K.D.,
Paris I., Worseck G., Gorosabel J.
<Mon. Not. R. Astron. Soc., 456, 4488-4505 (2016)>
=2016MNRAS.456.4488S 2016MNRAS.456.4488S (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Redshifts ; Abundances
Keywords: galaxies: evolution - galaxies: formation -
quasars: absorption lines - cosmology: observations
Abstract:
We present a sample of 38 intervening damped Lyman α (DLA)
systems identified towards 100 z>3.5 quasars, observed during the
XQ-100 survey. The XQ-100 DLA sample is combined with major DLA
surveys in the literature. The final combined sample consists of 742
DLAs over a redshift range approximately 1.6<zabs<5.0. We develop a
novel technique for computing ΩHIDLA as a continuous
function of redshift, and we thoroughly assess and quantify the
sources of error therein, including fitting errors and incomplete
sampling of the high column density end of the column density
distribution function. There is a statistically significant redshift
evolution in ΩHIDLA (≥3σ) from z∼2 to z∼5. In order
to make a complete assessment of the redshift evolution of
ΩHI, we combine our high-redshift DLA sample with absorption
surveys at intermediate redshift and 21-cm emission line surveys of
the local universe. Although ΩHIDLA, and hence its redshift
evolution, remains uncertain in the intermediate-redshift regime
(0.1<zabs<1.6), we find that the combination of high-redshift data
with 21-cm surveys of the local universe all yield a statistically
significant evolution in ΩHI from z∼0 to z∼5 (≥3σ).
Despite its statistical significance, the magnitude of the evolution
is small: a linear regression fit between ΩHI and z yields a
typical slope of ∼0.17x10-3, corresponding to a factor of ∼4
decrease in ΩHI between z=5 and z=0.
Description:
The XQ-100 survey is an ESO Large Program (ESO ID 189.A-0424, P.I. S.
Lopez) which obtained X-shooter spectra of 100 3.5<z<4.7 QSOs in
the period between 2012-02-10 and 2014-02-23. X-shooter is a
triple-arm spectrograph which obtains moderate-resolution spectra
with complete wavelength coverage from ∼320-2500nm, permitting the
simultaneous analysis of QSO absorption lines and emission features
from the atmospheric cut-off to the near-IR.
Based on the results of the XQ-100 survey, we report the detection of
38 intervening DLAs identified towards 100 z>3.5 QSOs. This sample
has been combined, after exhaustive checking for duplications and
errors, with a literature sample of DLA surveys spanning the last
∼20 years.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 116 108 XQ-100 DLA catalog
table5.dat 84 5874 Combined sample catalogue
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- n_Name [ABC ] Note on Name (1)
4- 13 A10 --- Name XQ-100 name (JHHMM+DDMM)
15- 20 F6.4 --- zem ? Emission redshift
23- 28 F6.4 --- zmin ? Minimum redshift range
31- 36 F6.4 --- zmax ? Maximum redshift range
39- 44 F6.4 --- zabs ? Absorption redshift
47- 51 F5.2 [cm-2] logN(HI) ? HI column density
55- 58 F4.2 [cm-2] e_logN(HI) ? rms uncertainty on logN(HI)
63-116 A54 --- Lines Lines covered
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Note (1): Note as follows:
A = DLA already identified in a previous survey
B = PDLA
C = color biased sight-line
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- QSO QSO name
31- 39 F9.5 deg RAdeg Rigth ascension (J2000)
41- 48 F8.4 deg DEdeg Declination (J2000)
50- 54 F5.3 --- zem ?=- Emission redshift
56- 60 F5.3 --- zmin ?=- Minimum redshift range
62- 66 F5.3 --- zmax ?=- Maximum redshift range
68- 73 F6.4 --- zabs ?=- Absorption redshift
75- 79 F5.2 [cm-2] logN(HI) ?=- HI column density
81- 84 F4.2 [cm-2] e_logN(HI) ?=- rms uncertainty on logN
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Oct-2016