KECK AND VLT OBSERVATIONS OF SUPER-DAMPED Ly α ABSORBERS AT z ∼ 2–2.5: CONSTRAINTS ON CHEMICAL COMPOSITIONS AND PHYSICAL CONDITIONS

We report Keck/Echellette Spectrograph and Imager and Very Large Telescope/Ultraviolet-Visual Echelle Spectrograph observations of three super-damped Ly alpha quasar absorbers with H i column densities log N[sub H i] [> or =] 21.7 at redshifts 2 [< or ~] z [< or ~] 2.5. We combine our results with those for other damped Lya a absorbers (DLAs) to examine trends between N[sub H i], metallicity, and dust depletion. For DLAs with log N[sub H i] [] 21.7 may have somewhat narrower velocity dispersions Delta v[sub 90] than the less gas-rich DLAs, and may arise in cooler and/or less turbulent gas.