DTPA Seminar: Petra Suková

The Department of Theoretical Physics and Astrophysics invites you to the department seminary:

Petra Suková: Can We Detect Small-Mass-Ratio Inspirals in the Electromagnetic Spectrum?

In recent years, large all-sky X-ray surveys have uncovered new astrophysical phenomena—repeating nuclear transients, which are short bursts of activity recurring on timescales ranging from hours to years.

Among these, one exceptional source, ASASSN-20qc, has exhibited quasi-periodic ultra-fast outflows with a varying column density approximately every eight days, superimposed on an ongoing tidal disruption event. Various physical mechanisms have been proposed to explain this behavior, with the most promising scenario involving a smaller, likely intermediate-mass black hole orbiting a supermassive black hole at a distance of roughly a hundred gravitational radii. As the secondary black hole plunges through the accretion flow, it generates high-velocity gas blobs, leading to repeated absorption events. I will present the key characteristics of such systems and demonstrate how GRMHD simulations can model this phenomenon. In the future, an extended search for repeating nuclear transients may help identify ongoing extreme or intermediate mass-ratio inspirals, providing valuable targets for the upcoming space-based gravitational-wave observatories, e.g. LISA.