Insights into tidal disruption of stars from PS1-10jh

Was PS1-10jh, an optical/ultraviolet transient discovered by the Pan-STARRS Medium Deep Survey, the tidal disruption of a star by a massive black hole (BH)? We address two aspects of the problem: the composition of the putative disrupted object (using the spectroscopic data), and the energetics of the observed gas and radiation (using the photometric data). We perform photoionization calculations and compare with the observed lower limit of the line ratio L-He II (4686)/L-H alpha > 5 to argue that this event was not the disruption of a solar-type star, and instead was likely the disruption of a helium core (as first proposed by Gezari et al.). Disruption of such a dense object requires a relatively small central BH, M-BH less than or similar to 2 x 10(5) M-circle dot. We use the photometric data to infer that PS1-10jh comprised an outflow of similar to 0.01M(circle dot) of gas, escaping from the BH at similar to 1000 km s(-1), and we propose that this outflow was driven primarily by radiation pressure trapped by Thomson and resonance line scattering. The large ratio of radiated energy to kinetic energy, E-rad/E-K similar to 10(4), together with the large value of E-rad similar to 2 x 10(51) erg, suggests that the outflow was shocked at large radius (perhaps similar to superluminous supernovae or the internal shock model for gamma-ray bursts). We describe puzzles in the physics of PS1-10jh, and discuss how this event may help us understand future tidal disruptions and super-Eddington accretion events as well.