The Properties of Low Redshift Intergalactic O VI Absorbers Determined from High S/N Observations of 14 QSOs with the Cosmic Origins Spectrograph

Abstract

We report on the observed properties of the plasma revealed through high signal-to-noise (S/N) observations of 54 intervening O VI absorption systems containing 85 O VI and 133 H I components in a blind survey of 14 QSOs observed at ~18 km s-1 resolution with the Cosmic Origins Spectrograph (COS) over a redshift path of 3.52 at z < 0.5. Simple systems with one or two H I components and one O VI component comprise 50% of the systems. For a sample of 45 well-aligned absorption components where the temperature can be estimated, we find evidence for cool photoionized gas in 31 (69%) and warm gas (6 > log T > 5) in 14 (31%) of the components. The total hydrogen content of the 14 warm components can be estimated from the temperature and the measured value of log N(H I). The very large implied values of log N(H) range from 18.38 to 20.38 with a median of 19.35. The metallicity, [O/H], in the 6 warm components with log T > 5.45 ranges from -1.93 to 0.03 with a median value of -1.0 dex. Ground-based galaxy redshift studies reveal that most of the absorbers we detect sample gas in the IGM extending 200 to 600 kpc beyond the closest associated galaxy. We estimate the warm aligned O VI absorbers contain (4.1+/-1.1)% of the baryons at low z. The warm plasma traced by the aligned O VI and H I absorption contains nearly as many baryons as are found in galaxies.

107 pages, 24 figures, accepted by the Astrophysical Journal Supplement

References in corpus (20)

• Time-Dependent Ionization in Radiatively Cooling Gas
• A High-Resolution Survey of Low-Redshift QSO Absorption Lines: Statistics and Physical Conditions of O VI Absorbers
• Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-Line Spectroscopy
• The Low-z Intergalactic Medium. III. HI and Metal Absorbers at z<0.4
• An improved measurement of the flux distribution of the Ly-alpha forest in QSO absorption spectra: the effect of continuum fitting, metal contamination and noise properties
• X-Ray Absorption from the Milky Way Halo and the Local Group
• The Far Ultraviolet Spectroscopic Explorer Survey of OVI Absorption in the Disk of the Milky Way
• Physical Properties, Baryon Content, and Evolution of the LyαForest: New Insights from High Resolution Observations at z < 0.4
• The Nature and Origin of Low-Redshift O VI Absorbers
• Where are the ``Missing'' Galactic Baryons?
• Numerical Study of Turbulent Mixing Layers with Non-Equilibrium Ionization Calculations
• X-ray and UV spectroscopy of Galactic diffuse hot gas along the LMC X--3 sight line
• A STIS Survey for OVI Absorption Systems at 0.12 < z < 0.5 II.: Physical Conditions of the Ionised Gas
• A STIS Survey for OVI Absorption Systems at 0.12 < z < 0.5 I.: The Statistical Properties of Ionized Gas
• Absorption signatures of warm-hot gas at low redshift: OVI
• The O VI Absorbers Toward PG0953+415: High Metallicity, Cosmic-Web Gas Far From Luminous Galaxies
• Low Redshift Intergalactic Absorption Lines in the Spectrum of HE0226-4110
• MHD Turbulent Mixing Layers: Equilibrium Cooling Models
• Warm-hot gas in groups and galaxies toward H2356-309
• Discovery of a large-scale galaxy filament near a candidate intergalactic X-ray absorption system

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