2014/07/24 by W. Peter Maksym, W. P. Maksym, Melville Ulmer +17 · 29 citations
Medicine · Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Black hole (networking) #Dwarf galaxy #Flare #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy merger #Gamma-ray bursts and supernovae #Interacting galaxy #Medicine #Physics #Population #Supermassive black hole #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.1093/mnras/stu1485
published in Monthly Notices of the Royal Astronomical Society 444(1), 866-873 (Oxford University Press) · 9 pages, 4 figures. Accepted by MNRAS
arxiv created 2014/07/24 · arxiv updated 2014/07/28 · openalex publication_date 2014/08/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 disk-instability flare from a weak AGN could not be dismissed. We have now obtained 8 hours of Gemini spectroscopy which unambiguously demonstrate that the host galaxy is indeed an extremely low-mass (M_∗∼ 3× 108 \rm M\odot) 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 (\rm log[M\bullet/\rm M\odot] ∼ 5.3 - 5.7) and infer a 15-year X-ray variability of a factor of > 104. 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.