1999/03/26 by G. Vladilo, Giovanni Vladilo, Vladilo, Giovanni
Engineering · Physics and Astronomy · #Astrophysics (astro-ph) #Calibration and Measurement Techniques #FOS: Physical sciences #Satellite Image Processing and Photogrammetry #Spacecraft Design and Technology #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9903406
15 pages, 2 figures, Invited Talk, Proc. of "The Evolution of Galaxies on Cosmological Timescales", eds. J.E. Beckman, and T.J. Mahoney, ASP Conf. Series, in press
arxiv created 1999/03/26 · openalex publication_date 1999/03/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The main properties of Damped Lyman alpha (DLA) systems are briefly reviewed with the aim of studying the nature and evolution of the galaxies associated with this class of QSO absorbers. Candidate DLA galaxies identified at z = 1 in the fields of background QSOs show a variety of morphological types without a predominance of spirals. Most properties inferred from spectroscopic studies at z >/= 1.65 differ from those expected for spiral galaxies. The observational results instead suggest that a significant fraction of DLA systems originate in low-mass and/or LSB galaxies. Evolution effects are generally not detected in DLA systems. This fact suggests that the differences between the properties of present-day spirals and those of high-z DLA systems may not be ascribed to evolution. Several selection effects can bias the observed population of DLA absorbers. Analysis of these effects indicates that the fraction of spiral galaxies tends to be underestimated relative to the fraction of low-mass or LSB galaxies.