dc.contributor.advisor Rudnick, Gregory H dc.contributor.author Lee-Brown, Donald dc.date.accessioned 2017-05-15T03:08:07Z dc.date.available 2017-05-15T03:08:07Z dc.date.issued 2016-12-31 dc.date.submitted 2016 dc.identifier.other http://dissertations.umi.com/ku:15003 dc.identifier.uri http://hdl.handle.net/1808/24174 dc.description.abstract Understanding how galaxies stop forming stars is a principle pursuit of extragalactic astrophysics. Here, I present a study of the relation between galaxy stellar age and mass in the $z=1.62$ protocluster IRC 0218. After separating star forming and quiescent galaxies on the basis of their $UVJ$ colors, we find that at stellar masses $M_* \ge 10^{10.8} M_{\odot}$, the quiescent fraction in IRC 0218 is $f_Q=1.0^{+0.00}_{-0.36}$, approximately $2-3 \times$ higher than the field value. At lower masses, $f_Q$ is consistent with the field. Using galaxy $D_{n}(4000)$ values as measures of stellar age, we find no relation between age and mass. This may indicate that the mass dependence of $f_Q$ was imprinted early in IRC 0218's history. Alternatively, the lack of a relation may be due to mass redistribution through gasless merging. Ultimately, our results place constraints on the mechanism(s) responsible for quenching in dense environments at $z\ge 1.5$. dc.format.extent 49 pages dc.language.iso en dc.publisher University of Kansas dc.rights Copyright held by the author. dc.subject Astronomy dc.subject Astrophysics dc.subject Galaxies dc.subject Galaxy Clusters dc.subject Galaxy Evolution dc.title The Ages of Passive Galaxies in a z=1.62 Protocluster dc.type Thesis dc.contributor.cmtemember Anthony-Twarog, Barbara J dc.contributor.cmtemember Hawley, Steven A dc.thesis.degreeDiscipline Physics & Astronomy dc.thesis.degreeLevel M.S. dc.identifier.orcid dc.rights.accessrights openAccess
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