Evolution of quasar absorption-selected galaxies

Abstract

We present the results of a survey of galaxies selected by their gas cross-section which give rise to MgII absorption lines in the spectra of background quasars. The sample comprises 11 galaxies covering the redshift range 0.7 < z < 1.2, and is combined with a lower redshift sample of 15 MgII absorbing galaxies. The spectra range from present-day elliptical to irregular galaxies. The strong corrleation found previously at lower redshift, between the halo radius and the galaxy luminosity still holds at z=1. For the low and high redshift samples, we have built template spectra by combining individual galaxies spectra. We use these templates to analyse the mean abundance and the past history of star formation of the MgII absorbing galaxies.