The X-ray/γ-ray spectrum of XTE J1550-564 in the very high state

Marek Gierliński (Lead / Corresponding author), Chris Done

Research output: Contribution to journalArticlepeer-review

59 Citations (Scopus)


We fit the broad-band X-ray/γ-ray spectrum (0.8-1000 keV) of the accreting black hole XTE J1550-564 in the very high state. The quasi-simultaneous data from ASCA, RXTE and OSSE (on CGRO) show that the disc is strongly Comptonized, with a high-energy tail extending out to several hundred keV. However, inverse Compton scattering by a purely thermal or purely power-law electron distribution cannot explain the observed spectrum. Instead, the data require a hybrid distribution, with both thermal and non-thermal electrons scattering the disc photons. This is very similar to the electron distribution inferred for other high and very high state black hole binaries, showing that it is a generic feature of high mass accretion rate black holes.

Original languageEnglish
Pages (from-to)1083-1092
Number of pages10
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
Publication statusPublished - 11 Jul 2003


  • Accretion
  • Accretion discs
  • Radiation mechanisms: javascript:void(0);non-thermal
  • X-rays: binaries
  • X-rays: individual
  • XTE J1550-564

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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