Abstract
The results of 23 km s-1 resolution echelle spectroscopy of the Lyman forest region of the z = 3.38 QSO 0014+813 are described. Voigt profile fits to the Lyman series absorption lines yield H I column density and Doppler parameter distributions similar to those obtained in three previous studies of other objects. There is no evidence so far of significant changes of the behavior of these distributions with redshift, except for the number of systems per unit redshift which, for log N(H I) > 13.75 (cgs), is proportional to (1 + z)2.1 ± 0.5. We find no evidence for a correlation between the Doppler parameter and column density and show that an apparent correlation is due entirely to selection effects of line detection and fitting. While the Lyman forest systems as a whole show no clustering, there appears to be a population of weak, narrow-lined systems which show clustering on scales of ≲1000 km s-1. It is not clear if these are unidentified heavy element lines or a genuine Lyman forest component. A simple test for voids along the sight line to 0014+813 proved negative. However, applying the same test to the spectrum of 0420-388 reveals a 24 Mpc region where the line number density is significantly below the mean. The depletion is unlikely to be due to a single nearby ionization source.
Original language | English (US) |
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Pages (from-to) | 387-404 |
Number of pages | 18 |
Journal | Astrophysical Journal |
Volume | 390 |
Issue number | 2 |
DOIs | |
State | Published - May 10 1992 |
Keywords
- Integalactic medium
- Quasars: absorption lines
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science