Speaker
Description
The SRG/eROSITA all-sky survey provides unique capabilities to explore the extragalactic transient and variable X-ray sky. While previous studies showed a dominance of AGN variability, a rare subset of sources in such a survey is expected to arise from more exotic phenomena such as tidal disruption events (TDEs), quasi-periodic eruptions (QPEs) or other short-lived non-AGN events associated with supermassive black hole accretion. In this talk, I will highlight the extraordinary properties of candidate TDEs discovered by eROSITA in eRASS1-5 and show the diversity of their X-ray and multi-wavelength behaviour. I will cover repeating partial TDE with timescales from months to decades, TDEs with unusual host galaxies, eROSITA’s constraints on the onset of accretion disk formation and the time scales for corona formation and destruction, and show that the X-ray evolution of TDEs rarely follows the canonical fall-back driven expectation.
Furthermore, I will describe the methodology used to compile the largest systematically selected sample (>300 sources) of extragalactic X-ray transients without prior signs of AGN activity (eRO-ExTra) from which a golden sample of ~30 TDEs was selected. The fundamental properties, including the X-ray and multi-wavelength light curves, spectral characteristics, and host galaxy properties, will be summarised, and the TDE luminosity function and occurrence rate will be discussed.
