On the outbursts of black hole soft X-ray transients

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Ertan U., Alpar M.

ASTRONOMY & ASTROPHYSICS, vol.393, no.1, pp.205-214, 2002 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 393 Issue: 1
  • Publication Date: 2002
  • Doi Number: 10.1051/0004-6361:20020998
  • Journal Name: ASTRONOMY & ASTROPHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.205-214
  • Keywords: accretion, accretion disks, instabilities, stars : binaries : cose, X-rays : general, IRRADIATED ACCRETION DISKS, LIMIT-CYCLE MECHANISM, LIGHT CURVES, THERMAL-INSTABILITY, SECONDARY MAXIMA, MODEL, EVOLUTION, EVAPORATION, BINARIES, CLUES
  • Middle East Technical University Affiliated: No

Abstract

We suggest a new scenario to explain the outburst light curves of black hole soft X-ray transients together with the secondary maximum and the bump seen on their decay phases. Our explanations are based on the disk instability models considering the effect of X-ray irradiation. The scenario is consistent with the observed X-ray delays by a few days with respect to the optical rise for both the main outburst and the later maxima. We test our scenario by numerically solving the disk diffusion equation. The obtained model curve fits well to the observed X-ray outburst photon flux curve of the black hole soft X-ray transient GS/GRS 1124-68, a typical representative of the four BH SXTs with very similar light curves.