Multi-phase gas properties of extremely strong intervening DLAs towards quasars
arXiv:2201.06413 · doi:10.1051/0004-6361/202140604
Abstract
We present the results of a spectroscopic analysis of extremely strong damped Lyman-α absorbers (ESDLAs, log N(Hi)>=21.7) observed with VLT-XShooter. ESDLAs probe gas from within the star-forming disk of the associated galaxies and thus ESDLAs provide a unique opportunity to study the interstellar medium of galaxies at high-redshift. We report column densities (N), equivalent widths (w), and the kinematic spread (Δ v90) of species from neutral, singly ionised, and higher ionisation species. We find that, using the dust correction prescription, the measured metallicities are consistent for singly ionised gas species such as Pii, S ii, Si ii, Mnii and Crii, and Znii in all ESDLAs within 3-sigma uncertainty. We find that the distributions of N(Ari)/N(Hi) ratio in DLAs and ESDLAs are similar. We further report that ESDLAs do not show a strong deficiency of Ari relative to other α-capture elements as is seen in DLAs. This supports the idea that the mentioned under-abundance of Ari in DLAs is possibly caused by the presence of background UV photons that penetrate the low N(Hi) clouds to ionise Ari, but they cannot penetrate deep enough in the high N(Hi) ESDLA environment. The w(Mgii lambda2796) distribution in ESDLAs is found to be similar to that of metal-rich Ci-selected absorbers, but the velocity spread of their Mgii profile is different. For higher ionisation species (such as C iv and Si iv), Δ v90 is similar in the two populations, while the Δ v90 of singly ionised species is smaller for ESDLAs. This suggests that the ESDLAs sample a different Hi region of their associated galaxy compared to the general DLA population. We further study the N(Cl i) distribution in high-redshift DLA and ESDLA sightlines, as Cl i is a good tracer of H2 gas. The N(Cl i)-N(H2) correlation is followed by all the clouds (ESDLAs and otherwise) having log N(H2)<22.
16 pages, 12 figures, 16 page appendix, 14 figures in appendix
References in corpus (23)
- Velocity-Metallicity Correlation for high-z DLA Galaxies: Evidence for a Mass-Metallicity Relation?
- Molecular hydrogen in high-redshift Damped Lyman-alpha systems: The VLT/UVES database
- The Neutral Hydrogen Cosmological Mass Density at z=5
- High-Ion Absorption in Seven GRB Host Galaxies at z=2-4: Evidence for both Circumburst Plasma and Outflowing Interstellar Gas
- A connection between extremely strong Damped Lyman-alpha Systems and Lyman-alpha Emitting Galaxies at small impact parameters
- C IV absorption in damped and sub-damped Lyman-alpha systems: correlations with metallicity and implications for galactic winds at z~2-3
- Discovery of a Perseus-like cloud in the early Universe: HI-to-H2 transition, carbon monoxide and small dust grains at zabs=2.53 towards the quasar J0000+0048
- Excitation mechanisms in newly discovered H2-bearing Damped Lyman-alpha clouds: systems with low molecular fractions
- CO-dark molecular gas at high redshift: very large H content and high pressure in a low metallicity damped Lyman-alpha system
- The Nitrogen and Oxygen abundances in the neutral gas at high redshift
- Optical/near-infrared selection of red QSOs: Evidence for steep extinction curves towards galactic centers?
- VLT/UVES observations of extremely strong intervening damped Lyman-alpha systems: Molecular hydrogen and excited carbon, oxygen and silicon at log N(HI)=22.4
- A study of the circum-galactic medium at z ~ 0.6 using DLA-galaxies
- The Fractional Ionization of the Warm Neutral Interstellar Medium
- Calcium H & K and sodium D absorption induced by the interstellar and circumgalactic media of the Milky Way
- The elusive HI-> H2 transition in high-z damped Lyman-alpha systems
- Neutral chlorine and molecular hydrogen at high redshift
- Dust depletion, chemical uniformity and environment of CaII H&K quasar absorbers
- Variations in the D/H ratio of extended sightlines from FUSE observations
- HD 62542: Probing the Bare, Dense Core of a Translucent Interstellar Cloud
- Chlorine in the Galactic ISM: Revised f-values with FUSE and STIS
- The ESO UVES Advanced Data Products Quasar Sample - IV. On the deficiency of Argon in DLA systems
- Extremely strong DLAs at high redshift: Gas cooling and H formation