Circling the Cosmic Drain: Analysis, Characterization and Variability of Local, Accreting X-ray Binaries with Archival Chandra Observations

Observations of X-ray binaries (XRBs) in nearby galaxies provide the best opportunity to study some of the universe’s most extreme environments, including the strong gravity of compact objects and the high-energy physics of the plasma found in their accretion disks. XRBs are known to cycle through distinct X-ray emission states, directly tied to their accretion rate; observing a full cycle would allow a determination of the nature of the compact object as either a neutron star or a black hole and provide insight into the dynamics and evolution of such systems. However, the timescales for these cycles range from days to decades, prohibiting detailed analysis of large samples. For this reason, we have conducted detailed spectro-temporal analysis on a flux-limited sample of X-ray sources in the local universe. Our group has conducted a volume-limited census of XRBs within 15 Mpc, a sample including upwards of 45,000 individual sources extracted from archival Chandra observations spanning from its launch to May of 2016. We have imposed on this sample a lower limit of 2,000 counts, yielding a sample of ~80 sources representing ~0.66% of total sources which, with appropriate binning, allows for statistically significant differentiation between unique spectral models. Here we present preliminary determinations of X-ray spectral state for each of these sources, additional analysis for sources exhibiting behavior indicative of quasiperiodicity and X-ray spectral state transitions, and commentary on implications of these results for the initial sample of XRBs.