%0 Generic %1 berg2021subdamped %A Berg, Trystyn A. M. %A Fumagalli, Michele %A D'Odorico, Valentina %A Ellison, Sara L. %A Lopez, Sebastian %A Becker, George D. %A Christensen, Lise %A Cupani, Guido %A Denney, Kelly D. %A Sanchez-Ramirez, Ruben %A Worseck, Gabor %D 2021 %K library %T Sub-damped Lyman alpha systems in the XQ-100 survey II -- Chemical evolution at 2.4<z<4.3 %U http://arxiv.org/abs/2101.07821 %X We present the measured gas-phase metal column densities in 155 sub-damped Lyman alpha systems (subDLAs) with the aim to investigate the contribution of subDLAs to the chemical evolution of the Universe. The sample was identified within the absorber-blind XQ-100 quasar spectroscopic survey over the redshift range 2.4<=z<=4.3. Using all available column densities of the ionic species investigated (mainly CIV, SiII, MgII, SiIV, AlII, FeII, CII, and OI; in order of decreasing detection frequency), we estimate the ionization-corrected gas-phase metallicity of each system using Markov Chain Monte Carlo techniques to explore a large grid of Cloudy ionization models. Without accounting for ionization and dust depletion effects, we find that the HI-weighted gas-phase metallicity evolution of subDLAs are consistent with damped Lyman alpha systems (DLAs). When ionization corrections are included, subDLAs are systematically more metal-poor than DLAs (between ~0.5 sigma and ~3 sigma significance) by up to ~1.0 dex over the redshift range 3<=z<=4.3. The correlation of gas-phase Si/Fe with metallicity in subDLAs appears to be consistent with that of DLAs, suggesting that the two classes of absorbers have a similar relative dust depletion pattern. As previously seen for Lyman limit systems, the gas-phase C/O in subDLAs remains constantly solar for all metallicities indicating that both subDLAs and Lyman limit systems could trace carbon-rich ejecta, potentially in circumgalactic environments.

@misc{berg2021subdamped, abstract = {We present the measured gas-phase metal column densities in 155 sub-damped Lyman alpha systems (subDLAs) with the aim to investigate the contribution of subDLAs to the chemical evolution of the Universe. The sample was identified within the absorber-blind XQ-100 quasar spectroscopic survey over the redshift range 2.4<=z<=4.3. Using all available column densities of the ionic species investigated (mainly CIV, SiII, MgII, SiIV, AlII, FeII, CII, and OI; in order of decreasing detection frequency), we estimate the ionization-corrected gas-phase metallicity of each system using Markov Chain Monte Carlo techniques to explore a large grid of Cloudy ionization models. Without accounting for ionization and dust depletion effects, we find that the HI-weighted gas-phase metallicity evolution of subDLAs are consistent with damped Lyman alpha systems (DLAs). When ionization corrections are included, subDLAs are systematically more metal-poor than DLAs (between ~0.5 sigma and ~3 sigma significance) by up to ~1.0 dex over the redshift range 3<=z<=4.3. The correlation of gas-phase [Si/Fe] with metallicity in subDLAs appears to be consistent with that of DLAs, suggesting that the two classes of absorbers have a similar relative dust depletion pattern. As previously seen for Lyman limit systems, the gas-phase [C/O] in subDLAs remains constantly solar for all metallicities indicating that both subDLAs and Lyman limit systems could trace carbon-rich ejecta, potentially in circumgalactic environments.}, added-at = {2021-01-21T07:59:26.000+0100}, author = {Berg, Trystyn A. M. and Fumagalli, Michele and D'Odorico, Valentina and Ellison, Sara L. and Lopez, Sebastian and Becker, George D. and Christensen, Lise and Cupani, Guido and Denney, Kelly D. and Sanchez-Ramirez, Ruben and Worseck, Gabor}, biburl = {https://www.bibsonomy.org/bibtex/2effce8a0522715c158a5504b2afd7a6b/gpkulkarni}, description = {Sub-damped Lyman alpha systems in the XQ-100 survey II -- Chemical evolution at 2.4<z<4.3}, interhash = {659c5a1569df94baa84cbfbf6a6c005a}, intrahash = {effce8a0522715c158a5504b2afd7a6b}, keywords = {library}, note = {cite arxiv:2101.07821Comment: Accepted for publication in MNRAS. 64 pages (20 pages of main text, 44 pages of Figures in appendix). Machine-readable versions of Tables 2 and 3 are available in the source files or available online on MNRAS}, timestamp = {2021-01-21T07:59:26.000+0100}, title = {Sub-damped Lyman alpha systems in the XQ-100 survey II -- Chemical evolution at 2.4<z<4.3}, url = {http://arxiv.org/abs/2101.07821}, year = 2021 }