The majority of X-ray point sources in the Milky Way are close accreting binaries, whose complex evolution is affected by dynamical interactions in dense environments like globular clusters (GCs). Identifying these exotic systems is crucial for understanding binary stellar evolution. Their periodic X-ray variability is a powerful diagnostic, confirming system properties and revealing evolutionary histories.
In this talk, I will demonstrate how we processed a systematic approach using the Gregory-Loredo algorithm, an ideal technique for sparse X-ray data on deep Chandra observations to overcome these challenges. Our findings span two extreme environments: In the Galactic Bulge, our search identified 25 periodic sources (predominantly magnetic cataclysmic variables), revealing a period distribution consistent with the Bulge’s overall advanced age. In the Globular Clusters, our comprehensive analysis of 11 GCs, including the most detailed study of 47 Tuc, established the largest sample of GC CVs with known orbital periods. This sample shows a marked shift toward longer periods and a high concentration toward the cluster center, providing strong evidence that dynamical formation dominates CV production, potentially suppressing the primordial evolution pathway.
Finally, I will show how these results provide new observational constraints for binary evolution models. We found that a significant fraction of CVs in GCs reside in the outskirt, consistent with dynamical ejection. This work establishes X-ray timing as a key diagnostic tool for charting the lifecycle of exotic binaries.