First submission -540248356 Assigned ID: 4332 ----- Attempting Submission 1 (Wed May 24 13:54:15 GMT 2023) ----- X-ray binaries with high-mass (>8 solar) donors play a critical role in several high-stakes astrophysics questions, including the re-ionization of the universe and the nature of advanced-LIGO sources. Addressing these questions requires knowledge of high-mass X-ray binary (HMXB) demographics (their scaling with host SFR) and environments that are unattainable from current state-of-the-art studies of X-ray luminosity functions. We aim to produce the first homogeneous catalog of HMXBs by classifying bright, Chandra-detected X-ray point sources based on their optical counterparts in multi-band HST imaging. We focus on a sample of 8 nearby spiral galaxies with publicly available, high-fidelity compact cluster and OB association catalogs produced by the PHANGS-HST survey and complete Chandra Source Catalog coverage. The results of this investigation will enable us to address fundamental questions about HMXBs formation efficiency, age distribution, and natal kicks. The proposing team brings together expertise in HST-based observations of stellar populations (including compact clusters, associations, and individual stars), X-ray binaries and Chandra observations, and theoretical work related to X-ray binaries and other high-energy processes that affect galaxies. Chandar, Gallo, Hunt: co-authors on several papers that have developed techniques to classify X-ray binaries in nearby spiral galaxies and to separate them from contaminants based on optical counterparts, exactly as proposed here. Floyd, Thilker, Lee: have played a leading role in creating the compact cluster and OB association catalogs from the PHANGS-HST collaboration. Lopez: X-ray data analysis and interpretation of point sources and diffuse emission in the Milky Way and nearby galaxies. Glover, Klessen: specialize in simulations and theoretical work on star formation in clusters and associations, including feedback and high energy processes. Schinnerer, Leroy, Mathur, Groves: members of the PHANGS collaboration who bring expertise in the ALMA CO and MUSE IFU observations. Stellar Populations and the Interstellar Medium Stellar Physics and Stellar Types 0 Regular false false false false false false SUPPORTED