X-ray Binaries: Windows to Astrophysical Phenomena

My research focuses on tracing the importance of luminous accreting black holes and neutrons stars, a.k.a. X-ray binaries (XRBs), across cosmic time. Actively accreting XRBs are bright snapshots of the complex evolution of binaries, encoding information about compact object demographics, accretion physics, and stellar evolution.

X-ray Binary Feedback: from the Early Universe to Today

Theoretical binary population synthesis models coupled with output from cosmological simulations suggest that XRBs are an important, and perhaps dominant, source of heating for the intergalactic medium at very high redshift, prior to the Epoch of Reionization. The radiative and mechanical feedback from XRBs in the earliest galaxies may also facilitate the escape of ionizing photons.

Unfortunately, we cannot directly observe XRB populations at these earliest cosmic epochs. I therefore use observations of XRB populations in nearby galaxies, particularly those with properties similar to galaxies in the early Universe, along with simulations to understand how the radiative output of XRBs scales with host galaxy properties such as star formation history and metallicity. These scaling relations for XRB population output with host galaxy properties are critical to understanding the contribution of XRB feedback in the earliest galaxies, where XRB populations cannot be directly observed. A list of my publications can be found here.