The High Energy X-ray Probe (HEX-P): Broadband X-ray Observations of Magnetars and Other Young Isolated Neutron Stars

HEX-P is a probe-class mission concept that will combine high spatial resolution X-ray imaging (<10 arcsec FWHM) and broad spectral coverage (0.1-150 keV) with an effective area far superior to current facilities (including XMM-Newton and NuSTAR) to enable revolutionary new insights into a variety of important astrophysical problems. HEX-P observations will address important open questions in magnetar and high-B pulsar physics such as (1) the trigger of the ‘transient’ outburst epochs in high-B neutron stars and the dissipative mechanism of the ensuing surface thermal and magnetospheric non-thermal energy enhancement, thereby constraining untwisting magnetic-field loops and thermal crustal relaxation models; (2) the mechanism behind magnetar short bursts and their connection to fast radio bursts; (3) establishing the broad-band SED of persistently luminous magnetars and its variability pattern with rotational phase, potentially testing fundamental predictions of quantum electrodynamics. Finally, HEX-P will illuminate our understanding of the evolutionary pathways of young NSs, with the goal of constraining the populations of Central Compact Objects (CCOs), magnetars, gamma-ray pulsars, and normal radio pulsars. We will present simulations of HEX-P observations of the diverse types of young isolated NSs, and demonstrate how HEX-P’s unique broadband spectral and timing capabilities will advance our understanding of these topical sources. More information on HEX-P, including the full team list, is available at http://hexp.org.