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We present preliminary results from a program designed to study the relationship between low redshift quasar absorption systems and galaxies, groups, and clusters of galaxies. We have been obtaining redshifts of the galaxies in the fields of several quasars observed by the Faint Object Spectrograph of the Hubble Space Telescope as part of the Quasar Absorption Line Key Project (Bahcall et al. 1993, ApJS, 87, 1). Our catalogue of galaxy redshifts combined with the catalogue of absorbers being prepared by the Key Project will allow a statistical examination of the relationship between Lyman alpha absorption clouds and galaxies in close proximity to the quasar line-of-sight.
Our study involves the construction of cross-correlation histograms revealing the amount and distribution of clustering between the Lyman alpha absorbers and galaxies as seen along several sight lines. Specifically, we plan to address the question of whether the absorbing clouds are typically found in regions of peaked galaxy distribution or in voids. We also explore direct associations between the galaxies in our sample and specific Lyman alpha and metal absorbers as seen in the HST data and comment on the implied absorption cross sections of the objects.
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