0 Assigned ID: 330 ----- Attempting Submission 1 (Fri Apr 11 02:14:06 GMT 2014) ----- HST Phase I Proposal 330 (cluster_hst22.pdf.apt) successfully submitted. ----- Attempting Submission 2 (Fri Apr 11 16:19:01 GMT 2014) ----- We propose to use the densest known environments at 1 < z < 2 as laboratories to understand the importance of galaxy mergers in the formation and quenching of massive bulge-dominated galaxies. High redshift proto-clusters are the progenitors of today's massive clusters; yet at z > 1, they are less dense, with lower velocity dispersions, active star-formation, and are often recently assembled unrelaxed systems. Direct and indirect evidence points to rapid rates of galaxy assembly via mergers in these environments as compared to the field (e.g. Lotz et al. 2013). Therefore, they are ideal places for studying the connection between galaxy mergers, bulge formation, AGN activity, and quenching at this critical time in formation of early-type galaxies. We propose to use HST archival imaging and grism data of 18 z > 1 proto-clusters to identify galaxy mergers, emission-line AGN, and quenching spheroids. By comparing stellar mass controlled samples from proto-clusters to those drawn from CANDELS/3D-HST field samples, we will determine if bulge formation, AGN triggering, and quenching in massive galaxies at z > 1 are driven by galaxy mergers. UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE Default Medium false false false false false SUPPORTED