Studying the Forming Clusters of Galaxies over Cosmic time in the X-ray and UV with STAR-X

STAR-X is a Medium Explorer class mission recently selected for a competitive NASA Phase A study. Comprising complementary wide-field, high-throughput, high-spatial-resolution X-ray and UV telescopes, STAR-X is designed to conduct deep wide-field surveys and respond rapidly to transient events discovered by other observatories in order to study the “fast, furious and forming Universe.” We present the key “forming” science pillar, which will explore the growth of large scale structure in the Universe. STAR-X will detect and characterize galaxy protoclusters at z>3 from AGN point-source overdensities, and simultaneously and uniquely constrain the presence of a hot intra-protocluster medium. STAR-X will discover thousands of new galaxy clusters at 1<z<2, tracing the evolution of the hot intracluster medium (ICM) from its epoch of formation to the present day to determine the history of AGN and supernova heating and metal enrichment. In the local Universe, STAR-X will unveil how massive galaxy clusters accrete matter by measuring temperature, density, and entropy profiles to beyond the virial radius, detecting low-entropy clumps that bias low spatial resolution X-ray measurements. More information on STAR-X, including details about the observatory and the list of team members, is available at http://star-x.xraydeep.org.