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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 (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:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 116 108 XQ-100 DLA catalog table5.dat 84 5874 Combined sample catalogue
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
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
Note (1): Note as follows: A = DLA already identified in a previous survey B = PDLA C = color biased sight-line
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
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
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Oct-2016
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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