<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bachetti, Matteo</style></author><author><style face="normal" font="default" size="100%">Middleton, Matthew J.</style></author><author><style face="normal" font="default" size="100%">Pinto, Ciro</style></author><author><style face="normal" font="default" size="100%">Gúrpide, Andrés</style></author><author><style face="normal" font="default" size="100%">Walton, Dominic J.</style></author><author><style face="normal" font="default" size="100%">Brightman, Murray</style></author><author><style face="normal" font="default" size="100%">Lehmer, Bret</style></author><author><style face="normal" font="default" size="100%">Roberts, Timothy P.</style></author><author><style face="normal" font="default" size="100%">Vasilopoulos, Georgios</style></author><author><style face="normal" font="default" size="100%">Alford, Jason</style></author><author><style face="normal" font="default" size="100%">Amato, Roberta</style></author><author><style face="normal" font="default" size="100%">Ambrosi, Elena</style></author><author><style face="normal" font="default" size="100%">Dai, Lixin</style></author><author><style face="normal" font="default" size="100%">Earnshaw, Hannah P.</style></author><author><style face="normal" font="default" size="100%">El Byad, Hamza</style></author><author><style face="normal" font="default" size="100%">García, Javier A.</style></author><author><style face="normal" font="default" size="100%">Luca Israel, Gian</style></author><author><style face="normal" font="default" size="100%">Jaodand, Amruta</style></author><author><style face="normal" font="default" size="100%">Madsen, Kristin</style></author><author><style face="normal" font="default" size="100%">Maitra, Chandreyee</style></author><author><style face="normal" font="default" size="100%">Mandel, Shifra</style></author><author><style face="normal" font="default" size="100%">Mori, Kaya</style></author><author><style face="normal" font="default" size="100%">Pintore, Fabio</style></author><author><style face="normal" font="default" size="100%">Ohsuga, Ken</style></author><author><style face="normal" font="default" size="100%">Pilia, Maura</style></author><author><style face="normal" font="default" size="100%">Stern, Daniel</style></author><author><style face="normal" font="default" size="100%">Younes, George</style></author><author><style face="normal" font="default" size="100%">Wolter, Anna</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The high energy X-ray probe (HEX-P): studying extreme accretion with ultraluminous X-ray sources</style></title><short-title><style face="normal" font="default" size="100%">Frontiers in Astronomy and Space Sciences</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Astrophysics - High Energy Astrophysical Phenomena</style></keyword><keyword><style  face="normal" font="default" size="100%">Astrophysics - Instrumentation and Methods for Astrophysics</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2023</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2023/11/1</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://ui.adsabs.harvard.edu/abs/2023FrASS..1089432B</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">1289432</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Introduction: Ultraluminous X-ray sources (ULXs) represent an extreme class of accreting compact objects: from the identification of some of the accretors as neutron stars to the detection of powerful winds travelling at 0.1–0.2 c, the increasing evidence points towards ULXs harbouring stellar-mass compact objects undergoing highly super-Eddington accretion. Measuring their intrinsic properties, such as the accretion rate onto the compact object, the outflow rate, the masses of accretor/companion-hence their progenitors, lifetimes, and future evolution-is challenging due to ULXs being mostly extragalactic and in crowded fields. Yet ULXs represent our best opportunity to understand super-Eddington accretion physics and the paths through binary evolution to eventual double compact object binaries and gravitational-wave sources. Methods: Through a combination of end-to-end and single-source simulations, we investigate the ability of HEX-P to study ULXs in the context of their host galaxies and compare it to XMM-Newton and NuSTAR, the current instruments with the most similar capabilities.Results: HEX-P's higher sensitivity, which is driven by its narrow point-spread function and low background, allows it to detect pulsations and broad spectral features from ULXs better than XMM-Newton and NuSTAR.Discussion: We describe the value of HEX-P in understanding ULXs and their associated key physics, through a combination of broadband sensitivity, timing resolution, and angular resolution, which make the mission ideal for pulsation detection and low-background, broadband spectral studies.</style></abstract></record></records></xml>