Surveying From the Farthest to Nearest Black Holes to EXIST

The Energetic X-ray Imaging Survey Telescope (EXIST) mission has been proposed to Astro2010 to conduct the deepest full-sky hard X-ray (5-600 keV) survey for black holes on all scales. With its combination of a very large area (4.5m²) High Energy Telescope (HET; 1.5arcmin imaging from 5-600 keV), Soft X-ray Imager (SXI; 0.1-10keV focusing telescope with 15arcsec psf) and optical-IR Telescope (IRT; 0.3-2.3 microns, with 4arcmin FoV and 0.15arcsec pixels), the EXIST mission has unsurpassed multiwavelength capabilities. It it is designed to detect the highest redshift Gamma-ray Bursts (GRBs), with predicted rates of 600/year and >20/y at z >7 and with prompt SXI localization (<1arcsec) and IRT imaging and spectra to determine redshifts and spectra that are sensitive to the ionization state of the local IGM and thus epoch of reionization. Its capability for AGN are similarly impressive, with known Blazars detectable out to z 8 if they exist. And for ULX and stellar mass black holes in the Local Group and Milky Way, the deepest inventory as well as long term variability studies are possible, as well as the first survey for isolated IMBHs accreting from GMCs. The mission combines both scanning (like Fermi/LAT) for increased sensitivity (vs. pointing) and sky coverage as well as followup pointings. The science, instrumentation, and mission overview are presented. As a Medium class mission, and with no new technology required, EXIST could be launched by 2017 to complement Fermi, JWST, ALMA, LOFAR and LSST and other wide-field surveys as well as followup studies planned for the coming decade.