An Optical/NIR Exploration of Forming Cluster Environments at High Redshift with VLT, Keck, and HST

The past decade has been witness to immense progress in the understanding of the early stages of cluster formation both from a theoretical and observational perspective. During this time, samples of forming clusters at higher redshift, termed "protoclusters", once comprised of heterogeneous mix of serendipitous detections or detections arising from dedicated searches around rare galaxy populations, have begun to compete with lower-redshift samples both in terms of numbers and in the homogeneity of the detection methods. Much of this progress has come from optical/near-infrared (NIR) imaging and spectroscopic campaigns designed to target large numbers of typical galaxies to exquisite depth.

In this poster talk I will focus on observations from VIMOS on VLT, MOSFIRE/DEIMOS on Keck, and a 50-orbit cycle 29 HST WFC3/G141 grism campaign taken as part of the Charting Cluster Construction with VUDS and ORELSE (C3VO) survey. These observations, combined with novel mapping and search techniques, have uncovered a large number of "protostructures" at 2 < z < 5 that appear to resemble clusters and groups forming in the early universe. I will discuss the development of the methods for finding, confirming, and characterizing proto-clusters and proto-groups in our sample, as well as groups and clusters at intermediate redshifts. Several case studies of spectroscopically-confirmed massive proto-clusters with a diverse set of properties will be presented. I will finally discuss constraints on the relationship between star formation rate, stellar mass, and galaxy density at these redshifts