Event DetailsEvent Dates: Monday, September 16, 2013 - 4:00pmSeminar Location: JILA AuditoriumSpeaker Name(s): Gillian WilsonSpeaker Affiliation(s): University of California - Riverside Seminar Type/SubjectScientific Seminar Type: Astrophysical & Planetary Sciences ColloquiaEvent Details & Abstract: Between z = 2 and z = 1, the main progenitors of present-day massive clusters undergo rapid collapse, and have high rates of galaxy merging and assembly, and cluster members transform from actively star-forming to quiescent. The SpARCS survey is one of the largest surveys designed to detect clusters of galaxies at z> 1, and has discovered hundreds of IR-selected clusters in the 50 square degree Spitzer SWIRE Legacy Fields. I will begin by reviewing the importance of clusters both to cosmology and to studies of galaxy evolution. I will show results from GCLASS, a 25-night Gemini/GMOS spectroscopic follow-up survey of ten of the most massive SpARCS clusters at z~1, and explain what this survey is teaching us about galaxy evolution in these, the densest of environments. I will also present a sample of newly-confirmed clusters at z~1.6 for which we have recently been awarded HST spectroscopy and imaging. I will conclude by discussing the motivation and challenges of hunting for protoclusters at z > 2.