The Star Formation Histories of Galaxies in the SC1324 Supercluster

Nelson Cheung

Abstract

We investigate the evolution of galaxies in dense environments in the early universe, quantifying the populations of passive, star forming, and starburst galaxies in the 346 spectroscopically confirmed members of the SC1324 supercluster at z ~ .76 as a part of the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. With spectroscopic data taken with the Deep Imaging Multi-Object Spectrograph (DEIMOS) on Keck II, we are able to create a spectroscopic catalog featuring the Equivalent Widths (EW) of [OII] and Hδ of the supercluster’s constituent galaxies. Using a spectral classification of star formation for galaxies, we create histograms showing the distribution of the different spectral types in the four clusters. Through these histograms, we are able to see that the supercluster members are each in different parts of their evolutionary history that correlates with the star-formation rates of the galaxies.   

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