Description
We present a comprehensive catalog of ultraviolet (HST/STIS and FUSE) absorbers in the low-redshift intergalactic medium (IGM) at z<0.4. The catalog draws from much of the extensive literature on IGM absorption and reconciles discrepancies among several previous catalogs through a critical evaluation of all reported absorption features in light of new HST/COS data. We report on 746 H I absorbers down to a rest-frame equivalent width of 12m{AA} over a maximum redshift path length {Delta}z=5.38. We also confirm 111 O VI absorbers, 29 C IV absorbers, and numerous absorption lines due to other metal ions. We characterize the bivariate distribution of absorbers in redshift and column density as a power law, ({partial}^2^N/{partial}z{partial}N){propto}N^-{beta}^, where {beta}=2.08+/-0.12 for O VI and {beta}=1.68+/-0.03 for H I. Utilizing a more sophisticated accounting technique than past work, our catalog accounts for ~43% of the baryons: 24+/-2% in the photoionized Ly{alpha} forest and 19+/-2% in the warm-hot IGM as traced by O VI. We discuss the large systematic effects of various assumed metallicities and ionization states on these calculations, and we implement recent simulation results in our estimates.
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