Browsing by Author "Ho, L. C."

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    Deep spectroscopy of the M-V similar to-14.8 host galaxy of a tidal disruption flare in A1795
    (Oxford University Press, 2014) Maksym, W. P.; Ulmer, M. P.; Roth, K. C.; Irwin, J. A.; Dupke, R.; Ho, L. C.; Keel, W. C.; Adami, C.; University of Alabama Tuscaloosa; Northwestern University; University of Michigan System; University of Michigan; Eureka Scientific; Peking University; Carnegie Institution for Science; UDICE-French Research Universities; Aix-Marseille Universite
    A likely tidal disruption of a star by the intermediate-mass black hole (IMBH) of a dwarf galaxy was recently identified in association with Abell 1795. Without deep spectroscopy for this very faint object, however, the possibility of a more massive background galaxy or even a disc-instability flare from a weak active galactic nucleus (AGN) could not be dismissed. We have now obtained 8 h of Gemini spectroscopy which unambiguously demonstrates that the host galaxy is indeed an extremely low mass (M-star similar to 3 x 10(8) M-circle dot) galaxy in Abell 1795, comparable to the least massive galaxies determined to host IMBHs via other studies. We find that the spectrum is consistent with the X-ray flare being due to a tidal disruption event rather than an AGN flare. We also set improved limits on the black hole mass (log[M-lozenge/M-circle dot] similar to 5.3-5.7) and infer a 15 yr X-ray variability of a factor of greater than or similar to 10(4). The confirmation of this galaxy-black hole system provides a glimpse into a population of galaxies that is otherwise difficult to study, due to the galaxies' low masses and intrinsic faintness, but which may be important contributors to the tidal disruption rate.
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    Deep spectroscopy of the M-V similar to-14.8 host galaxy of a tidal disruption flare in A1795
    (Oxford University Press, 2014) Maksym, W. P.; Ulmer, M. P.; Roth, K. C.; Irwin, J. A.; Dupke, R.; Ho, L. C.; Keel, W. C.; Adami, C.; University of Alabama Tuscaloosa; Northwestern University; University of Michigan System; University of Michigan; Eureka Scientific; Peking University; Carnegie Institution for Science; UDICE-French Research Universities; Aix-Marseille Universite
    A likely tidal disruption of a star by the intermediate-mass black hole (IMBH) of a dwarf galaxy was recently identified in association with Abell 1795. Without deep spectroscopy for this very faint object, however, the possibility of a more massive background galaxy or even a disc-instability flare from a weak active galactic nucleus (AGN) could not be dismissed. We have now obtained 8 h of Gemini spectroscopy which unambiguously demonstrates that the host galaxy is indeed an extremely low mass (M-star similar to 3 x 10(8) M-circle dot) galaxy in Abell 1795, comparable to the least massive galaxies determined to host IMBHs via other studies. We find that the spectrum is consistent with the X-ray flare being due to a tidal disruption event rather than an AGN flare. We also set improved limits on the black hole mass (log[M-lozenge/M-circle dot] similar to 5.3-5.7) and infer a 15 yr X-ray variability of a factor of greater than or similar to 10(4). The confirmation of this galaxy-black hole system provides a glimpse into a population of galaxies that is otherwise difficult to study, due to the galaxies' low masses and intrinsic faintness, but which may be important contributors to the tidal disruption rate.