Year: 2008
Type: article
Abstract: We present two luminous UV/optical flares from the nuclei of apparently inactive early-type galaxies at z = 0.37 and 0.33 that have the radiative properties of a flare from the tidal disruption of a star. In this paper we report the second candidate tidal disruption event discovery in the UV by the GALEX Deep Imaging Survey and present simultaneous optical light curves from the CFHTLS Deep Imaging Survey for both UV flares. The first few months of the UV/optical light curves are well fitted with the canonical t −5/3 power-law decay predicted for emission from the fallback of debris from a tidally disrupted star. Chandra ACIS X-ray observations during the flares detect soft X-ray sources with T bb = (2–5) × 10 5 K or Γ > 3 and place limits on hard X-ray emission from an underlying AGN down to L X (2–10 keV) ≲ 10 41 ergs s −1 . Blackbody fits to the UV/optical spectral energy distributions of the flares indicate peak flare luminosities of ≳10 44 -10 45 ergs s −1 . The temperature, luminosity, and light curves of both flares are in excellent agreement with emission from a tidally disrupted main-sequence star onto a central black hole of several times 10 7 M ☉ . The observed detection rate of our search over ~2.9 deg 2 of GALEX Deep Imaging Survey data spanning from 2003 to 2007 is consistent with tidal disruption rates calculated from dynamical models, and we use these models to make predictions for the detection rates of the next generation of optical synoptic surveys.
Source: The Astrophysical Journal
DOI: 10.1086/529008
Authors: S. Gezari, S. Basa, D. C. Martin, G. Bazin, K. Forster, B. Milliard, J. P. Halpern, P. G. Friedman, P. Morrissey, S. G. Neff, D. Schiminovich, M. Seibert, T. Small, T. K. Wyder
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2084835412