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Title: THE LOW-REDSHIFT INTERGALACTIC MEDIUM AS SEEN IN ARCHIVAL LEGACY HST/STIS AND FUSE DATA

Journal Article · · Astrophysical Journal
; ;  [1]
  1. CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States)

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 12 mA 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_derivative}{sup 2}N/{partial_derivative}z{partial_derivative}N) {proportional_to} N{sup -{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 {approx}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.

OSTI ID:
22086393
Journal Information:
Astrophysical Journal, Vol. 759, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English