AbstractsAstronomy & Space Science

Galaxy evolution is a very active field of current astrophysical research. Despite this,the question of how cluster mergers modulate the evolution of galaxies is unresolved. Given the ubiquity of cluster mergers and that some 5{10% of galaxies in the local Universe reside in clusters of galaxies, answering this question is of vital importance for gaining a complete understanding of the processes responsible for galaxy evolution. The aim of this thesis is to study galaxy evolution in a cluster merger and to link galaxy evolution to the merger. We collected optical spectra of galaxies in Abell 3667, a cluster merger system ~ 1 Gyr post-core passage, and in a sample of relaxed benchmark clusters with the 3.9m Anglo-Australian Telescope and 6.5m MMT Telescope down to M* +3. Single stellar population templates were fitted to the spectra to measure velocity dispersions and to broadly classify galaxies as absorption line or emission line systems. Lick indices were measured and were used to derive the age, [/Fe], [Fe/H] and [Z/H] stellar population parameters and the Balmer indices were used to classify post-starburst galaxies. Equivalent widths were measured for the H, H, [OIII] and [NII] emission lines. Emission line ratios were used to classify emission line galaxies into star-forming and AGN classes and star formation rates were estimated from H and D4000.