Golovich, Nathan and Dawson, William A. and Wittman, David M. and Jee, Myungkook J. and Benson, Bryant and Lemaux, Brian and Weeren, Reinout J. van and Andrade-Santos, Felipe and Sobral, David and Gasperin, Francesco de and Bruggen, Marcus and Bradac, Marusa and Finner, Kyle and Peter, Annika (2019) Merging Cluster Collaboration : Optical and Spectroscopic Survey of a Radio-Selected Sample of Twenty Nine Merging Galaxy Clusters. The Astrophysical Journal Supplement Series, 240 (2): 39. ISSN 0067-0049
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Abstract
Multi-band photometric and multi-object spectroscopic surveys of merging galaxy clusters allow for the characterization of the distributions of constituent dark matter and galaxy populations, constraints on the dynamics of the merging subclusters, and an understanding of galaxy evolution of member galaxies. We present deep photometric observations from Subaru/SuprimeCam and a catalog of $\sim$5400 spectroscopic cluster members from Keck/DEIMOS across 29 merging galaxy clusters ranging in redshift from $z=0.07$ to $0.55$. The ensemble is compiled based on the presence of radio relics, which highlight cluster scale collisionless shocks in the intra-cluster medium. Together with the spectroscopic and photometric information, the velocities, timescales, and geometries of the respective merging events may be tightly constrained. In this preliminary analysis, the velocity distributions of 28 of the 29 clusters are shown to be well fit by single Gaussians. This indicates that radio relic mergers largely occur transverse to the line of sight and/or near apocenter. In this paper, we present our optical and spectroscopic surveys, preliminary results, and a discussion of the value of radio relic mergers for developing accurate dynamical models of each system.