Kristen Garofali

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:


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:


Using facilities like Chandra, XMM-Newton, NuSTAR, HST, and SDSS, I study extragalactic XRB populations as a function of their host galaxy properties (i.e., star formation history and metallicity) to infer how XRB feedback scales with redshift. A list of my publications can be found here.