Chemical diversity of gas in distant galaxies

The chemical composition of gas in galaxies can be measured great detail using absorption spectroscopy. By studying this way, it is possible to investigate small and faint galaxies, which are the most numerous universe. In particular, distribution absorbing systems gives us insight into cycles around galaxies. work we study enrichment within 64 damped Lyman- α (DLAs) for redshifts range 1.7 < z 4.2. We use high-resolution spectra from VLT/UVES infer dust depletion relative abundances several metals. Specifically, performed a component-by-component analysis DLAs, characterised variations their enrichment. Unlike hydrogen, metal columns according individual components. used them derive depletion, an indicator Our main results as follows. Firstly, find that some DLAs chemically diverse themselves (with measure [Zn/Fe] fit ranging up 0.62 dex single system), suggesting these diverse. Secondly, although do not clear trend decreasing with redshift, see enriched at lower redshifts. also observe evidence dust-poor components all redshifts, may due accretion pristine onto combining kinematic properties components, potential signatures infalling low velocities below ∼100 km s −1 , outflows high ∼600 . Finally, over-abundances -elements (an enhancement ∼0.3 dex) under-abundances Mn likely signature core-collapse supernovae nucleosythesis ISM. effects mostly levels