Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-01-26
Mon.Not.Roy.Astron.Soc.379:1169-1194,2007
Astronomy and Astrophysics
Astrophysics
Accepted for publication in MNRAS, 29 pages, 24 figures. Minor changes
Scientific paper
10.1111/j.1365-2966.2007.12005.x
We carried out a survey for high-metallicity C IV absorbers at redshift z ~ 2.3 in the spectra of 9 high-quality quasar spectra. Using a novel analysis technique, based on detections of C IV lines and automatically determined upper limits on the column densities of H I, C III, N V, and O VI, we find a large (dN/dz > 7) population of photo-ionized, compact (R ~ 10^2 pc), metal-rich (Z >~ Z_solar) C IV clouds with moderate densities (n_H ~ 10^{-3.5} cm^{-3}), properties that we show are robust with respect to uncertainties in the ionization model. In particular, local sources of ionizing radiation, overabundance of oxygen, departures from ionization equilibrium, and collisional ionization would all imply more compact clouds. The clouds are too small to be self-gravitating and pressure confinement is only consistent under special conditions. We argue that the clouds are, in any case, likely to be short-lived and we demonstrate that this implies that the clouds could easily have been responsible for the transport of all metals that end up in the intergalactic medium (IGM). When the clouds reach pressure equilibrium with the general, photo-ionized IGM, the metals will still be concentrated in small high-metallicity patches, but they will look like ordinary, low-metallicity absorbers. We conclude that intergalactic metals are poorly mixed on small scales and that nearly all of the IGM, and thus the universe, may therefore be of primordial composition.
Carswell Robert F.
Kim Tae-Sun
Schaye Joop
No associations
LandOfFree
A large population of metal-rich, compact, intergalactic C IV absorbers - Evidence for poor small-scale metal mixing does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A large population of metal-rich, compact, intergalactic C IV absorbers - Evidence for poor small-scale metal mixing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A large population of metal-rich, compact, intergalactic C IV absorbers - Evidence for poor small-scale metal mixing will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-567909