The X-ray Emissivity of Low-Density Stellar Populations
Abstract
High-density stellar environments allow for close interactions between stars, which can lead to dense stellar remnants being placed into stellar binaries. In close orbits, matter can transfer from a normal star to the stellar remnant, producing radiation up to X-rays - for white dwarfs, these are cataclysmic variables (CVs). Observations of faint X-ray sources indicate CVs are more frequent in denser clusters and link dynamical processes with fainter X-ray binaries. However, previous studies noted that the total X-ray emissivity is lower in denser environments with no unique bright X-ray sources. So, either binaries are destroyed quickly in dense environments or open clusters lose a large fraction of their non-X-ray-emitting mass. We address this by considering the X-ray emissivity in a range of environments and densities. We find that the X-ray emissivity of environments below 10000 solar masses per parsec cubed are not density dominated. We find a significant correlation between X-ray emissivity and binary fraction and less significant correlations with metallicity and age. The available data is limited and sampling via bootstrap gives less significant correlations.
We'd like to acknowledge financial support from the Natural Sciences and Engineering Research Council of Canada.- Publication:
-
APS April Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..APRL08008I