KIPAC Tea Talk: Quasi-periodic eruptions: a new probe of supermassive black holes and extreme mass-ratio inspirals / TBD

Chakraborty Abstract: Quasi-periodic eruptions (QPEs) are a newly discovered type of recurring X-ray transient originating from supermassive black holes in nearby, low-mass galaxy nuclei. They are thought to be the first observed counterparts to extreme mass-ratio inspirals (EMRIs), long-anticipated gravitational wave sources detectable by future space-based interferometers (e.g. LISA). Thirteen QPEs are known, and in an unexpected twist, several have emerged from the accretion disks formed in tidal disruption events. I will give an overview of the surprising discoveries, observational properties, and theoretical progress in QPEs, including empirical constraints on their emission mechanisms, prospects for probing EMRI orbital dynamics using QPE timings, and estimates of the QPE rate and its implications for EMRI formation.