A Near-Solar Metallicity, Nitrogen-Deficient Lyman Limit Absorber Associated with two S0 Galaxies

The UV spectrum of the bright quasar PHL 1811 at zem = 0.192 reveals a foreground gas system at z = 0.080923 with logN(H I) = 17.98 ± 0.05. We have determined the abundances of various atomic species in this system from a spectrum covering the wavelength range 1160 to 1730 Å recorded at 7 km s resolution by the E140M grating of STIS on the Hubble Space Telescope (HST), supplemented by coverage at shorter wavelengths by the Far Ultraviolet Spectroscopic Explorer. The abundances of C II, Si II, S II and Fe II compared to that of O I indicate that a considerable fraction of the gas is in locations where the hydrogen is ionized. An oxygen abundance [O/H] = −0.19 ± 0.08 in the H Ibearing gas indicates that the chemical enrichment of the gas is unusually high for an extragalactic QSO absorption system. However, this same material has an unusually low abundance of nitrogen, [N/O] < −0.59, indicating that there may not have been enough time during this enrichment for secondary nitrogen to arise from low and intermediate mass stars. From the convergence of high Lyman series lines we can determine the velocity width of H I, and after correcting