QSO Absorbers: Evidence for a Primeval Galaxy Population
Abstract
Analyses of QSO absorption-line data including Lyα forest lines, metal-line absorbers, and damped Lyα systems indicate that the various classes of absorbers belong to the same parent population. In particular, the different absorber systems form a contiguous sequence on a total hydrogen surface density, velocity dispersion plane. Thus the Lyα forest absorbers represent the low column density, low-mass end of the larger metallic systems. In the majority of the absorption systems, cooling appears to have played an important role at the epoch of observation, although most systems have not evolved sufficiently to resemble the local galaxy population. Thus they represent a population of primeval, dynamically evolving systems. The data are more easily interpretable for a dark matter-dominated universe than for a purely baryonic universe. For a dark to baryonic matter ratio of 10, observations suggest that the ultimate fate of all QSO absorbers is to evolve into the local galaxy population.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1992
- DOI:
- 10.1086/171627
- Bibcode:
- 1992ApJ...395...21C
- Keywords:
-
- Dark Matter;
- Galactic Evolution;
- Lyman Alpha Radiation;
- Quasars;
- Absorption Spectra;
- Baryons;
- Charge Coupled Devices;
- Line Spectra;
- Astrophysics;
- COSMOLOGY: THEORY;
- COSMOLOGY: DARK MATTER;
- GALAXIES: FORMATION;
- GALAXIES: QUASARS: ABSORPTION LINES