Metals in the Intergalactic Medium

Abstract

We use high spectral resolution (R=45000) and high signal-to-noise ratio (S/N \~ 35-70 per pixel) spectra of 19 high-redshift (2.1<z_em<3.2) quasars to investigate the metal content of the low-density intergalactic medium using pixel-by-pixel procedures. This high quality homogeneous survey gives the possibility to statistically search for metals at HI optical depths smaller than unity. We find that the gas is enriched in carbon and oxygen for neutral hydrogen optical depths tau(HI)>1. Our observations strongly suggest that the CIV/HI ratio decreases with decreasing tau(HI) with log[tau(CIV)]=1.3xlog[tau(HI)]-3.2. We do not detect CIV absorption statistically associated with gas of tau(HI)<1. However, we observe that a small fraction of the low density gas is associated with strong metal lines as a probable consequence of the IGM enrichment being highly inhomogeneous. We detect the presence of OVI down to tau(HI)~0.2 with log[tau(OVI)/tau(HI)] -2.0. We show that OVI absorption in the lowest density gas is located within ~300 km/s from strong HI lines. This suggests that this OVI phase may be part of winds flowing away from overdense regions. This effect is more important at the largest redshifts (z>2.4). Therefore, at the limit of present surveys, the presence of metals in the underdense regions of the IGM is still to be demonstrated.

9 pages, 10 figures, accepted in A&A

References in corpus (15)

• Gravitational Collapse of Small-Scale Structure as the Origin of the Lyman Alpha Forest
• The Lyman-alpha Forest in the Cold Dark Matter Model
• Metallicity of the intergalactic medium using pixel statistics. II. The distribution of metals as traced by C IV
• Evolution of Structure in the Intergalactic Medium and the Nature of the Ly-alpha Forest
• The Distribution of Column Densities and b Values in the Lyman-Alpha Forest
• The Enrichment History of the Intergalactic Medium: Measuring the CIV/HI Ratio in the Lyman Alpha Forest
• Intrinsic Properties of the <z>=2.7 Lyman Alpha Forest from Keck Spectra of QSO HS 1946+7658
• The physical properties of the Ly-Alpha forest at z > 1.5
• Mixing Metals in the Early Universe
• The Redshift Evolution of the Metagalactic Ionizing Flux Inferred from Metal Line Ratios in the Lyman Forest
• Characterizing the Warm-Hot IGM at High Redshift: A High Resolution Survey for O VI at z = 2.5
• The detection of oxygen in the low-density intergalactic medium
• The enrichment history of the intergalactic medium: O VI in Ly-alpha forest systems at redshift z ~ 2
• The warm-hot intergalactic medium at z~2.2: Metal enrichment and ionization source
• Metallicity of the Intergalactic Medium Using Pixel Statistics: I. Method

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