The Effect of Metallicity on the High Mass X-Ray Binary Population
Abstract
Metallicity is known to play an important role in star formation activity, and thus plays an equally important role in the formation and observable properties of the resultant high mass X-Ray binary (HMXB) population. Since the age-specificity and high luminosity of HMXBs makes them a good tool in the study of star-forming activity, it is important to understand the exact role that metallicity plays in the observable characteristics of the HMXB population. Using the population synthesis code StarTrack, we model the HMXB population at several metallicities and examine the parameter space for HMXB creation. We find that the dominant pathway for HMXB production at high metallicity creates wind accretion systems with (super)-giant donors, while at low metallicity, systems undergoing accretion due to Roche-Lobe Overflow are highly preferred. This difference greatly affects the number, time evolution, orbital period distributions, and X-Ray luminosity functions of the HMXB population as a function of metallicity. Using these results, we make theoretical predictions for the population of Ultra-luminous X-Ray sources in low metallicity environments, as well as for the origin of the HMXB population in the starburst cluster NGC 1569.
- Publication:
-
AAS/High Energy Astrophysics Division #11
- Pub Date:
- March 2010
- Bibcode:
- 2010HEAD...11.2902L