J/MNRAS/488/4356 Sub-damped Lyα systems in XQ-100 survey (Berg+, 2019)
Sub-damped Lyman α systems in the XQ-100 survey.
I. Identification and contribution to the cosmological H I budget.
Berg T.A.M., Ellison S.L., Sanchez-Ramirez R., Lopez S., D'odorico V.,
Becker G.D., Christensen L., Cupani G., Denney K.D., Worseck G.
<Mon. Not. R. Astron. Soc., 488, 4356-4369 (2019)>
=2019MNRAS.488.4356B 2019MNRAS.488.4356B (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; H I data ; Redshifts ; Radio sources
Keywords: galaxies: high-redshift - galaxies: ISM - quasars: absorption lines
Abstract:
Sub-damped Lyman α systems (subDLAs; HI column densities of
19.0≤logN(HI)<20.3) are rarely included in the cosmic HI
census performed at redshifts zabs≥1.5, yet are expected to
contribute significantly to the overall HI mass budget of the
Universe. In this paper, we present a blindly selected sample of 155
subDLAs found along 100 quasar sightlines (with a redshift path-length
ΔX=475) in the XQ-100 legacy survey to investigate the
contribution of subDLAs to the H I mass density of the Universe. The
impact of X-Shooter's spectral resolution on Ly α absorber
identification is evaluated, and found to be sufficient for reliably
finding absorbers down to a column density of logN(HI)≥18.9.
We compared the implications of searching for subDLAs solely using HI
absorption versus the use of metal lines to confirm the
identification, and found that metal-selection techniques would have
missed 75 subDLAs. Using a bootstrap Monte Carlo simulation, we
computed the column density distribution function (f(N, X)) and the
cosmological H I mass density (OmegaHI) of subDLAs and compared
with our previous work based on the XQ-100 damped Lyman α
systems. We do not find any significant redshift evolution in f(N, X)
or OmegaHI for subDLAs. However, subDLAs contribute 10-20 per
cent of the total OmegaHI measured at redshifts 2<z<5, and
thus have a small but significant contribution to the HI budget of
the Universe.
Description:
The XQ-100 Legacy Survey (PI S. Lopez) observed 100 QSO sightlines at
redshift zem∼3.5-4.5 with the X-Shooter Spectrograph on the Very
Large Telescope (VLT) in Chile. The QSOs were purposefully chosen to
be blind to any intervening absorption line systems, thus providing a
random sample of sub-DLAs and DLAs to study the cosmological
implications of these intervening absorbers.
We present a metal-blind catalogue of 242 candidate absorbers with HI
column densities of 18.8≤logN(HI)<20.3, identified solely using their
HI absorption, in the XQ-100 legacy survey.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 37 276 HI absorbers in XQ-100
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See also:
J/MNRAS/456/4488 : XQ-100 survey neutral gas (Sanchez-Ramirez+, 2016)
J/MNRAS/462/3285 : XQ-100. X-shooter quasar spectra (Perrotta+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name QSO name (JHHMM+DDMM)
12- 16 F5.3 --- zem Emission redshift of the QSO
18- 24 F7.5 --- zabs Absorption redshift
26- 30 F5.2 [cm-2] logNHI Logarithm of HI column density
32- 35 F4.2 [cm-2] e_logNHI Error on logNHI
37 A1 --- Abs [Y/N] Detected metal absorption
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History:
From electronic version of the journal
References:
Lopez et al., 2016A&A...594A..91L 2016A&A...594A..91L
Sanchez-Ramirez et al., 2016MNRAS.456.4488S 2016MNRAS.456.4488S, Cat. J/MNRAS/456/4488
Perrotta et al., 2016MNRAS.462.3285P 2016MNRAS.462.3285P, Cat. J/MNRAS/462/3285
Berg et al., 2016MNRAS.463.3021B 2016MNRAS.463.3021B
Irsic et al., 2017MNRAS.466.4332I 2017MNRAS.466.4332I
Perrotta et al., 2018MNRAS.481..105P 2018MNRAS.481..105P
Berg et al., 2021MNRAS.502.4009B 2021MNRAS.502.4009B
(End) Ana Fiallos [CDS] 28-Dec-2022