The High Energy X-ray Probe (HEX-P) perspective on AGN: from accretion physics to supermassive black hole growth and feedback

HEX-P is a probe-class mission concept that will combine high spatial resolution X-ray imaging (<10 arcsec FWHM) and broad spectral coverage (0.1-150keV) with an effective area far superior to current facilities (including XMM-Newton and NuSTAR), enabling pioneering new insights into a variety of important astrophysical problems. The unique capabilities of HEX-P in observing active galactic nuclei (AGN) will enable breakthrough discoveries, connecting the extreme environment around the event horizons of supermassive black holes to downstream feedback jets and winds, in particular ultrafast outflows (UFOs). These observations will revolutionize our understanding of supermassive black hole growth and the important effect that these objects have on their host galaxies and the formation of structure in the Universe. HEX-P will (1) enable detailed measurements of the inner regions of the accretion flow; (2) extend our census of supermassive black hole spins beyond the local Universe; (3) probe particle acceleration in the vicinity of black holes and probe the physics of the X-ray emitting corona; and (4) make detailed measurements of ejection physics, including the launching of relativistic jets and ultrafast outflows, a key mechanism by which AGN can impart significant kinetic power into their surroundings. More information on HEX-P, including the full team list, is available at https://hexp.org.