Abstract
We present a study of the Lyman α forest of the QSO 1331 + 170 in the range 1.67 < Zabs < 2.10 at 18 km s-1 resolution. Our analysis includes a careful search for previously unidentified heavy-element systems, and incorporates detailed deblending of Lyα forest lines from heavy-element lines. Various statistical properties of Lyα forest lines, such as distributions of equivalent widths, H I column densities, Doppler parameters and pair-velocity separations, are computed. The effect on these properties of employing different limiting approaches to heavy-element deblending, and profile-fitting of the lines, is illustrated. Our data suggest that the NH1 distribution may not be fitted adequately by a single power law, i.e., that there may be a relative deficit of strong lines as compared with the predictions of a single power law. However, larger samples are required to verify this deficit. The median b value is ≈ 32 km s-1. No significant correlation is observed between NH1 and b. An excess on the scale of ∼ 100 km s-1 is seen in the pair-velocity correlations, at the level of ∼ 2.6σ for the conservative sample and at the level of ∼ 4.9σ for the less conservative sample. Marginal excess correlation is seen in both the samples at the ≳ 2σ level on scales of ∼ 800-1000 km s-1, and also on scales of ∼ 6000 km s-1.
Original language | English (US) |
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Pages (from-to) | 197-218 |
Number of pages | 22 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 279 |
Issue number | 1 |
DOIs | |
State | Published - 1996 |
Keywords
- Intergalactic medium
- Quasars: absorption lines
- Quasars: individual: Q1331 + 170
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science