Chemical abundances of the Damped Lyman Alpha systems in the XQ-100 survey

DOI: 
10.1093/mnras/stw2232
Publication date: 
01/12/2016
Main author: 
Berg, T. A. M.
IAA authors: 
Sánchez-Ramírez, R.
Authors: 
Berg, T. A. M.;Ellison, S. L.;Sánchez-Ramírez, R.;Prochaska, J. X.;Lopez, S.;D'Odorico, V.;Becker, G.;Christensen, L.;Cupani, G.;Denney, K.;Worsek, G.
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Pages: 
3021-3037
Abstract: 
The XQ-100 survey has provided high signal-noise spectra of 100 redshift 3-4.5 quasars with the X-Shooter spectrograph. The metal abundances for 13 elements in the 41 damped Lyα systems (DLAs) identified in the XQ-100 sample are presented, and an investigation into abundances of a variety of DLA classes is conducted. The XQ-100 DLA sample contains five DLAs within 5000 km s<SUP>-1</SUP> of their host quasar (proximate DLAs; PDLAs) as well as three sightlines which contain two DLAs within 10,000 km s<SUP>-1</SUP> of each other along the same line-of-sight (multiple DLAs; MDLAs). Combined with previous observations in the literature, we demonstrate that PDLAs with logN(HI)〈21.0 show lower [S/H] and [Fe/H] (relative to intervening systems with similar redshift and N(HI)), whilst higher [S/H] and [Si/H] are seen in PDLAs with logN(HI)〉21.0. These abundance discrepancies are independent of their line-of-sight velocity separation from the host quasar, and the velocity width of the metal lines (v<SUB>90</SUB>). Contrary to previous studies, MDLAs show no difference in [α/Fe] relative to single DLAs matched in metallicity and redshift. In addition, we present follow-up UVES data of J0034+1639, a sightline containing 3 DLAs, including a metal-poor DLA with [Fe/H]=-2.82 (the third lowest [Fe/H] in DLAs identified to date) at z<SUB>abs</SUB>=4.25. Lastly we study the dust-corrected [Zn/Fe], emphasizing that near-IR coverage of X-Shooter provides unprecedented access to MgII, CaII and TiII lines (at redshifts 3-4) to provide additional evidence for subsolar [Zn/Fe] ratio in DLAs.
Database: 
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2016MNRAS.463.3021B/abstract
ADS Bibcode: 
2016MNRAS.463.3021B
Keywords: 
galaxies: abundances;galaxies: high redshift;galaxies: ISM;quasars: absorption lines