Accretion disk spectra of the ultra-luminous compact X-ray sources in nearby spiral galaxies and the super-luminal jet sources

K. Ebisawa, A. Kubota, T. Mizuno, P. Zycki

Research output: Contribution to journalConference article

1 Citation (Scopus)


The Ultra-luminous Compact X-ray Sources (ULXs) in nearby spiral galaxies and the Galactic super-luminal jet sources share the common spectral characteristic that they have extremely high disk temperatures which cannot be explained in the framework of the standard accretion disk model in the Schwarzschild metric. We examine several possibilities to solve this "too-hot" disk problem. In particular, we have calculated an extreme Kerr disk model to fit the observed spectra. We found that the Kerr disk will become significantly harder compared to the Schwarzschild disk only when the disk is highly inclined. For super-luminal jet sources, which are known to be inclined systems, the Kerr disk model may work if we choose proper values for the black hole angular momentum. For the ULXs, however, the Kerr disk interpretation will be problematic, as it is highly unlikely that their accretion disks are preferentially inclined.

Original languageEnglish
Pages (from-to)415-418
Number of pages4
JournalEuropean Space Agency, (Special Publication) ESA SP
Issue number459
Publication statusPublished - 2001 Sep 1
Event4th Integral Workshop -Exploring the Gamma-Ray Universe-2000 - Alicante, Spain
Duration: 2000 Sep 42000 Sep 8



  • Accretion disks
  • Black holes
  • Super-luminal jet sources
  • Ultra-luminous X-ray sources

ASJC Scopus subject areas

  • Aerospace Engineering
  • Space and Planetary Science

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