X-ray Binary Population Luminosity Functions in Galaxies and their Dependence on Star-Formation History and Metallicity
Abstract
The formation of X-ray binary (XRB) populations in galaxies has long been understood to be sensitive to both galaxy star-formation history (SFH) and metallicity; however, the details of this relationship has not yet been clearly quantified. We will present a new empirical framework modeling the SFH and metallicity dependence of XRB population luminosity functions (XLFs) that self-consistently describes XRB populations over the full range of galaxy types. We test our model framework using ~2000 X-ray detected point-sources within 44 Chandra-observed galaxies at D < 30 Mpc that span a broad range of metallicity and SFH (spanning early-to-late type morphologies). Our models provide unifying quantitative context for scaling relations that have been well studied in the literature, including, e.g., the high-mass XRB (HMXB) luminosity versus SFR relation (LX(HMXB)/SFR), the LX(HMXB)-SFR-metallicity plane, the ultraluminous X-ray source frequency as a function of metallicity and age, the low-mass XRB (LMXB) luminosity scaling with stellar mass (LX(LMXB)/M*), and the observed evolution of LX(HMXB)/SFR and LX(LMXB)/M* relations with cosmic time. We will discuss how these relationships serve important roles in a variety of Astrophysical studies beyond XRB populations (e.g., AGN, gravitational wave sources, cosmological studies of the early Universe, ISM ionization, and population synthesis models).
- Publication:
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American Astronomical Society Meeting Abstracts #243
- Pub Date:
- February 2024
- Bibcode:
- 2024AAS...24330706L