Supersolar Super-Lyman Limit Systems

We present abundance measurements for two super Lyman Limit systems (SLLS;quasar absorption line systems with 10^19 cm^-2 < N_HI < 10^20.3 cm^-2)selected from a set of metal-strong absorbers in the Sloan Digital Sky Surveyquasar database. After applying estimate corrections for photoionizationeffects, we derive gas-phase metallicities of [M/H]=+0.7 +/- 0.2 dex for theSLLS at z=1.7749 toward SDSS0927+5621 and [M/H]=+0.05 +/- 0.1 dex for the SLLSat z=1.7678 toward SDSS0953+5230. The former exhibits among the highest gasmetallicity of any astrophysical environment and its total metal surfacedensity exceeds that of nearly every known damped Lya system. The properties ofthese absorbers -- high metallicity and large velocity width (> 300 km/s) --resemble those of gas observed in absorption in the spectra of bright,star-forming galaxies at high redshift. We discuss the metal mass density ofthe SLLS based on these observations and our ongoing SLLS survey and argue thata conservative estimate to the total metal budget at z=2 is greater than 15% ofthe total, suggesting that the metal-rich LLS may represent the dominant metalreservoir in the young universe.Comment: 6 pages, 2 figures. Submitted to ApJL; Revised June 22, 200