Description
Tidal disruption events (TDEs) are rare transients that occur when stars are torn apart by black holes and accreted. At X-ray energies, they are typically soft, thermal sources that slowly evolve over years or even decades, or harder sources produced by relativistic jets that decay rapidly when the jet turns off. In this talk, I will discuss a unique source discovered in archival Swift-XRT data that, while clearly a TDE, does not truly match either of these pictures. LSXPS J0956 is a soft thermal nuclear transient that initially decays slowly before exhibiting a precipitous decline roughly two years after initial detection, similarly to jetted TDEs. In contrast to LSXPS J0956, these events display power law spectra, however, viscous-like interactions with the surrounding medium can induce structure in the jet. If viewed slightly off-axis, the varying optical depth could produce the quasi-thermal spectrum observed in LSXPS J0956. Alternatively, if the star’s initial orbit is sufficiently eccentric, the entirety of the debris can remain bound to the black hole. The accretion rate decays slowly before dropping rapidly as all the material is accreted, again consistent with the behaviour of LSXPS J0956. In both cases, LSXPS J0956 would be the first observed example of such a transient and I will discuss the significant questions this unique source raises for the wider TDE population.
