Abstract

ABSTRACT We present a systematic search for periodic X-ray sources in the bulge of M31, using ∼2 Ms of archival Chandra observations spanning a temporal baseline of 16 yr. Utilizing the Gregory–Loredo algorithm that is designed for photon-counting, phase-folded light curves, we detect seven periodic X-ray sources, among which four are newly discovered. Three of these sources are novae, the identified periods of which range between 1.3 and 2.0 h and are most likely the orbital period. The other four sources are low-mass X-ray binaries, the identified periods of which range between 0.13 and 19.3 h and are also likely orbital due to a clear eclipsing/dipping behaviour in the light curve. We address implications on the X-ray binaries population of the M31 bulge. Our study demonstrates the potential of using archival X-ray observations to systematically identify periodic X-ray sources in external galaxies, which would provide valuable information about the underlying exotic stellar populations.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.