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Title: X-RAY TRANSIENTS: HYPER- OR HYPO-LUMINOUS?

Journal Article · · Astrophysical Journal Letters
;  [1]
  1. CNRS, UMR 7095, Institut d’Astrophysique de Paris, 98bis Bd Arago, F-75014 Paris (France)

The disk instability picture gives a plausible explanation for the behavior of soft X-ray transient systems if self-irradiation of the disk is included. We show that there is a simple relation between the peak luminosity (at the start of an outburst) and the decay timescale. We use this relation to place constraints on systems assumed to undergo disk instabilities. The observable X-ray populations of elliptical galaxies must largely consist of long-lived transients, as deduced on different grounds by Piro and Bildsten (2002). The strongly varying X-ray source HLX-1 in the galaxy ESO 243-49 can be modeled as disk instability of a highly super-Eddington stellar-mass binary similar to SS 433. A fit to the disk instability picture is not possible with an intermediate-mass black hole model for HLX-1. Other recently identified super-Eddington ULXs might be subject to disk instability.

OSTI ID:
22518816
Journal Information:
Astrophysical Journal Letters, Vol. 801, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English