Published in 1987, "QSO Absorption Lines: Probing the
Universe", eds. J.C. Blades, D.A. Turnshek and C.A. Norman
QSO ABSORPTION LINES: INTRODUCTION
W. L. W. Sargent
Palomar
Observatory,
California Institute of
Technology
Abstract. A brief account is given of the physical properties of
the heavy-element and
Ly-
forest absorption redshift
systems observed in QSO spectra. Theories for their
origin are summarized. It is emphasized that the two types of absorption
system have
qualitatively different properties and that they are almost certainly
not components of
a single population as Tytler has recently claimed. Extensive new data
on the
heavy-element redshifts reveal clustering on velocity scales unlikely to
have been produced
by the motions of clouds within galaxies. Extensive absorption systems
observed
in the relatively wide QSO pair Q1037-2704 and Q1038-2712 and in the
spectra of
other QSOs in the surrounding field are described. Observations of this
kind appear
to represent a new way of studying the large-scale distribution of
galaxies at earlier epochs in the expansion of the Universe.
Table of Contents
INTRODUCTION
- PROPERTIES OF THE HEAVY-ELEMENT REDSHIFTS
- PHYSICAL PROPERTIES OF THE
Ly- CLOUDS
- RECENT DEVELOPMENTS ON THE
Ly- FOREST
- ORIGIN OF THE HEAVY-ELEMENT REDSHIFTS
- THE ORIGIN OF THE
Ly- FOREST LINES
- NEW RESULTS ON CLUSTERING
- QSO ABSORPTION LINES AND LARGE-SCALE STRUCTURE
- THE QSO PAIR Q2343+1229, Q2344+1225
- CONCLUSIONS
- REFERENCES
