C iv absorption in damped and sub-damped Lyman-alpha systems: Correlations with metallicity and implications for galactic winds at z~2-3

摘要: We present a study of $\ion{C}{iv}$ absorption in sample 63 damped Lyman- α  (DLA) systems and 11 sub-DLAs the redshift range $1.75\! -1 FWHM ), high signal-to-noise VLT/UVES spectra. The complex absorption line profiles show both narrow broad $\ion{C}{iv}$ components, indicating presence warm, photoionized hot, collisionally ionized gas. report new correlations between metallicity (measured neutral-phase) each $\ion{C}{iv}$ column density, $\ion{C}{iv}$ total width, maximum $\ion{C}{iv}$ velocity. explore effect on these sub-DLAs, proximate DLAs (defined as those within 5000 km s  of quasar), saturated absorbers, metal used to measure metallicity, we find be robust. There is no evidence for any difference measured properties DLA $\ion{C}{iv}$ and sub-DLA $\ion{C}{iv}$. In 25 DLAs and 4 covering 2.5 dex in [Z/H], directly observe $\ion{C}{iv}$ moving above escape speed, where  v esc derived from total width neutral gas profiles. These high-velocity $\ion{C}{iv}$ clouds, unbound central potential well, can interpreted highly outflowing winds, which are predicted by numerical simulations galaxy feedback. distribution $\ion{C}{iv}$ column density sub-DLAs similar Lyman Break galaxies, where winds observed, supporting idea that supernova feedback creates DLAs. $\ion{C}{iv}$ absorbers median mass flow rate ~22 ( r /40 kpc) $M_\odot$ yr , characteristic $\ion{C}{iv}$ radius. Their kinetic energy fluxes large enough star formation (SFR) ~2 $M_\odot$ yr  is required power them.