PS1-10jh – a tidal disruption event with an extremely low disc temperature

Abstract

Abstract The cooler than expected optical–UV transient PS1-10jh detected by the Pan-STARRS1 survey is probably related to a tidal disruption event in which a He-rich stellar core remnant is implied. The evolution of bound debris during the disc-phase is studied by solving the hydrodynamic equations. The model provides a good fit either of the raising part of the light curve in the bands gP1, rP1 and iP1 or in the early decay. The parameters characterizing this optimized model are the mass of the central black hole, i.e. 6.3 × 106 M⊙, and the critical Reynolds number ${\cal R} = 10^4$ that fixes the viscosity and the accretion time-scale. Such a high value of ${\cal R}$ explains the low disc temperature and the consequent absence of X-ray emission. The predicted bolometric peak luminosity is about 1045 erg s− 1 and the predicted total radiated energy is about Erad = 2.67 × 1051 erg.