Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/29184
Title: | On the selection of damped Lyman α systems using Mg II absorption at 2 < z<SUB>abs</SUB> < 4 | Authors: | Berg, T. A. M. Ellison, S. L. Prochaska, J. X. Sánchez-Ramírez, R. Lopez, S. D'ODORICO, Valentina Becker, G. Christensen, L. CUPANI, Guido Denney, K. Worseck, G. |
Issue Date: | 2017 | Journal: | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | Number: | 464 | Issue: | 1 | First Page: | L56 | Abstract: | The XQ-100 survey provides optical and near-infrared coverage of 36 blindly selected, intervening damped Lyman α systems (DLAs) at 2 < z<SUB>abs</SUB> < 4, simultaneously covering the Mg II doublet at λλ2796, 2803Å, and the Ly α transition. Using the XQ-100 DLA sample, we investigate the completeness of selecting DLA absorbers based on their Mg II rest-frame equivalent width (W<SUB>0</SUB>^{2796}) at these redshifts. Of the 29 DLAs with clean Mg II profiles, we find that six (20 per cent of DLAs) have W<SUB>0</SUB>^{2796} < 0.6 Å. The DLA incidence rate of W<SUB>0</SUB>^{2796} < 0.6 Å absorbers is a factor of ∼5 higher than what is seen in z ∼ 1 samples, indicating a potential evolution in the Mg II properties of DLAs with redshift. All of the W<SUB>0</SUB>^{2796} < 0.6 Å DLAs have low metallicities (-2.5 < [M/H] < -1.7), small velocity widths (v<SUB>90</SUB> < 50 km s<SUP>-1</SUP>), and tend to have relatively low N(H I). We demonstrate that the exclusion of these low W<SUB>0</SUB>^{2796} DLAs results in a higher mean N(H I) which in turn leads to an ∼7 per cent increase in the cosmological gas density of H I of DLAs at 2 < z<SUB>abs</SUB> < 4; and that this exclusion has a minimal effect on the H I-weighted mean metallicity. | URI: | http://hdl.handle.net/20.500.12386/29184 | URL: | https://academic.oup.com/mnrasl/article/464/1/L56/2891003 | ISSN: | 0035-8711 | DOI: | 10.1093/mnrasl/slw185 | Bibcode ADS: | 2017MNRAS.464L..56B | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
slw185.pdf | pdf editoriale | 415.93 kB | Adobe PDF | View/Open |
Page view(s)
59
checked on Sep 11, 2024
Download(s)
20
checked on Sep 11, 2024
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are published in Open Access, unless otherwise indicated.