The high-energy observatory for imaging x-rays (HEROIX) broadband x-ray space telescope mission concept

The High EneRgy Observatory for Imaging X-rays (HEROIX) Medium-Class Mission concept is a next-generation broadband X-ray observatory designed to meet the astrophysics community’s need for high-angular resolution studies of the Cosmic X-ray Background (CXB) and the growth of supermassive black holes. Building on the science legacy of NASA’s NuSTAR mission and more than 30 years of advances in replicated NiCo shell technology at Marshall Space Flight Center, HEROIX proposes a space-based observatory comprising six co-aligned telescopes achieving 5-arcsecond half-power diameter (HPD) angular resolution. This capability, approached by the resolution demonstrated in the FOXSI-4 sounding rocket mission and under development through the SuperHERO balloon mission as well as Marshall’s X-ray optics program, will be extended to energies up to 79 keV through advanced multilayer coatings. Marshall’s in-house precision optics manufacturing enables an integrated effective area of 570 cm2 at 30 keV, which, combined with an order-of-magnitude improvement in angular resolution over current hard X-ray observatories, will open new windows into non-thermal processes in extreme astrophysical environments. HEROIX will provide decades of discovery for the high-energy astrophysics community, advancing our understanding of supernova physics, the X-ray binary population of the Galactic Center, and accretion-driven galaxy evolution.