26-30 June 2023
Centro Congressi Federico II
Europe/Rome timezone

A repeating partial tidal disruption event discovered by eROSITA

29 Jun 2023, 12:45
Aula Magna (Centro Congressi Federico II)

Aula Magna

Centro Congressi Federico II

Via Partenope, 36, Napoli, Italy


Zhu Liu


During its first two years of the All-Sky Survey, SRG/eROSITA uncovered a large sample of X-ray transients associated with the nuclei of quiescent galaxies. In this talk, I will highlight one exceptional repeating nuclear transient eRASSt J045650-203751 discovered by SRG/eROSITA. Extensive monitoring with XMM-Newton, Swift, NICER, and ATCA revealed four repeating X-ray flares and repeating transient radio emission. This makes J0456-20 one of the most promising repeating partial Tidal Disruption Event (pTDE) candidates. A detailed analysis of the available data shows that the characteristic X-ray variability for each flare can be best explained by the accretion state transitioning between the thermal and the steep power-law states, accompanied by the formation and destruction of the coronae. This indicates that similar accretion processes are at work across a broad range of BH masses and accretion rates and that the corona can be formed and destructed within a few weeks to months. I will also present evidence of a potential evolution of the recurrence time of the flares, hinting at a change in the orbital period of the stellar remnant. This highlights the role of repeating pTDEs as effective probes of the stellar dynamics around supermassive BHs beyond our Galaxy.

Primary authors

Zhu Liu Dr. Adam malyali (Max Planck Institute for Extraterrestrial Physics) Dr. Mirko Krumpe (Leibniz-Institut fuer Astrophysik Potsdam (AIP)) David Homan (Leibniz-Insitut für Astrophysik Potsdam) Arne Rau (Max Plank Institute for Extraterrestrial Physics) Dr. Andrea Merloni (Max Planck Institute for Extraterrestrial Physics) Iuliia Grotova (Max Planck Institute for Extraterrestrial Physics)

Presentation Materials

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