When a black hole tidally disrupts a star, accretion of the debris will produce a luminous flare and reveal the presence of a dormant black hole. Emission lines produced when the stellar debris and/or other gas in the black hole's vicinity are photoionized by the accretion flare have considerable diagnostic power. I will discuss models of the emission line spectrum produced in the debris released when evolved stars are tidally disrupted by an intermediate-mass black hole (100-10000 solar masses), and discuss the possibility of using the emission lines to identify such events and constrain the properties of the black hole. While there is some agreement between these models and observations of white dwarf tidal disruption candidates in globular clusters associated with NGC 4472 and NGC 1399, there are also drawbacks to interpreting these sources as tidally disrupted white dwarfs. I will also present results from time-dependent photoionization calculations that model the emission line spectrum produced when ambient, circumnuclear gas is illuminated by a tidal disruption flare. The emission line light curves are consistent with the transient extreme coronal line emitters recently identified in SDSS. These tidal disruption event light echoes can be used to probe the circumnuclear environments of quiescent galaxies and to constrain the extreme UV component of tidal disruption flares.
UNLV Physics & Astronomy Forum Schedule