The STAR-X science case: Studying the Fast, Furious and Forming Universe in the X-ray and UV

The STAR-X MIDEX mission proposal is a timely response to Astro2020’s recommendation for a space-based, sustaining time-domain and multi-messenger program. The science theme for the mission is “to study the fast, furious and forming Universe.” The “Fast” theme covers transients such as supernova shock breakouts, electromagnetic radiation from neutron star-neutron star mergers detected by ground-based gravitational wave detectors and stellar flares that affect exoplanet atmospheres. The “Furious” theme covers large and rapid amounts of accretion onto black holes, so as to understand rapid black hole growth at earlier times in our Universe, and involves study of Tidal Disruption Events of stars around black holes and time-domain reverberation studies of accretion disk geometry. The third pillar, “Forming”, concerns the growth of large scale structure in the Universe, covering the growth of massive galaxy clusters from their epoch of formation at z>3 to their ongoing growth from the filaments of the cosmic web at the current time. This talk will cover these science objectives and how the simultaneous X-ray and UV coverage of STAR-X will achieve them. More information on STAR-X, including the full team list, is available at http://star-x.xraydeep.org.