An ultraviolet-optical flare from the tidal disruption of a helium-rich stellar core.

Journal Article (Journal Article)

The flare of radiation from the tidal disruption and accretion of a star can be used as a marker for supermassive black holes that otherwise lie dormant and undetected in the centres of distant galaxies. Previous candidate flares have had declining light curves in good agreement with expectations, but with poor constraints on the time of disruption and the type of star disrupted, because the rising emission was not observed. Recently, two 'relativistic' candidate tidal disruption events were discovered, each of whose extreme X-ray luminosity and synchrotron radio emission were interpreted as the onset of emission from a relativistic jet. Here we report a luminous ultraviolet-optical flare from the nuclear region of an inactive galaxy at a redshift of 0.1696. The observed continuum is cooler than expected for a simple accreting debris disk, but the well-sampled rise and decay of the light curve follow the predicted mass accretion rate and can be modelled to determine the time of disruption to an accuracy of two days. The black hole has a mass of about two million solar masses, modulo a factor dependent on the mass and radius of the star disrupted. On the basis of the spectroscopic signature of ionized helium from the unbound debris, we determine that the disrupted star was a helium-rich stellar core.

Full Text

Duke Authors

Cited Authors

  • Gezari, S; Chornock, R; Rest, A; Huber, ME; Forster, K; Berger, E; Challis, PJ; Neill, JD; Martin, DC; Heckman, T; Lawrence, A; Norman, C; Narayan, G; Foley, RJ; Marion, GH; Scolnic, D; Chomiuk, L; Soderberg, A; Smith, K; Kirshner, RP; Riess, AG; Smartt, SJ; Stubbs, CW; Tonry, JL; Wood-Vasey, WM; Burgett, WS; Chambers, KC; Grav, T; Heasley, JN; Kaiser, N; Kudritzki, R-P; Magnier, EA; Morgan, JS; Price, PA

Published Date

  • May 2012

Published In

Volume / Issue

  • 485 / 7397

Start / End Page

  • 217 - 220

PubMed ID

  • 22575962

Electronic International Standard Serial Number (EISSN)

  • 1476-4687

International Standard Serial Number (ISSN)

  • 0028-0836

Digital Object Identifier (DOI)

  • 10.1038/nature10990

Language

  • eng