Luminous [O III] and [N II] from Tidally Disrupted Horizontal Branch Stars
arXiv:1205.3053 · doi:10.1111/j.1365-2966.2012.21305.x
Abstract
We model the emission lines generated in the photoionised debris of a tidally disrupted horizontal branch star. We find that at late times, the brightest optical emission lines are [N II] λλ6548,6583 and [O III] λλ4959,5007. Models of a red clump horizontal branch star undergoing mild disruption by a massive (50 -- 100 M_\sun) black hole yield an emission line spectrum that is in good agreement with that observed in the NGC 1399 globular cluster hosting the ultraluminous X-ray source CXOJ033831.8 - 352604. We make predictions for the UV emission line spectrum that can verify the tidal disruption scenario and constrain the mass of the BH.
8 pages, 6 figures, Accepted for publication in MNRAS