University of Hertfordshire

From the same journal

From the same journal

By the same authors

A Transient Black-Hole Low-Mass X-Ray Binary Candidate in Centaurus A

Research output: Contribution to journalArticlepeer-review

  • G.R. Sivakoff
  • R.P. Kraft
  • A. Jordan
  • A.M. Juett
  • D.A. Evans
  • W.R. Forman
  • M.J. Hardcastle
  • C.L. Sarazin
  • M. Birkinshaw
  • Nicola Brassington
  • J.H. Croston
  • W.F. Harris
  • C. Jones
  • S.S. Murray
  • S. Raychaudhury
  • K.A. Woodley
  • D.M. Worrall
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Original languageEnglish
Pages (from-to)L27-L30
JournalThe Astrophysical Journal
Publication statusPublished - 2008


We report the discovery of a bright transient X-ray source, CXOU J132518.2–430304, toward Centaurus A (Cen A) using six new Chandra X-Ray Observatory observations in 2007 March-May. Between 2003 and 2007, its flux has increased by a factor of >770. The source is likely a low-mass X-ray binary in Cen A with unabsorbed 0.3-10 keV band luminosities of (2-3) × 1039ergs s−1 and a transition from the steep-power-law state to the thermal state during our observations. CXOU J132518.2–430304 is the most luminous X-ray source in an early-type galaxy with extensive timing information that reveals transience and a spectral state transition. Combined with its luminosity, these properties make this source one of the strongest candidates to date for containing a stellar-mass black hole in an early-type galaxy. Unless this outburst lasts many years, the rate of luminous transients in Cen A is anomalously high compared to other early-type galaxies.


Original article can be found at: Copyright American Astronomical Society DOI: 10.1086/587960 [Full text of this article is not available in the UHRA]

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