Speaker
Description
Quasi-periodic eruptions (QPEs) are an emerging class of high amplitude bursts of X-ray radiation, repeating on a hours-day timescale, recently discovered near the central supermassive black holes (SMBHs) of a few low-mass galaxies. I will briefly review our current theoretical understanding of QPEs, and the different classes of proposed theoretical interpretations. I will focus on a scenario involving a main-sequence star repeatedly colliding with an accretion flow onto the SMBH, twice per orbit. I will show how this model naturally reproduces the observed period, luminosity, emission temperature, duration, occurrence rate of QPEs, as well as the possible association between TDEs and QPEs. I will also discuss the implications of the observations and of our model for probing the accretion physics around SMBHs, the rate of extreme mass ratio inspirals (EMRIs) for future space-based gravitational wave detectors, and the discovery prospects of related repeating nuclear transients in light of upcoming UV surveys such as ULTRASAT and UVEX.
