The Galactic black-hole binary GRO J1655-40 was observed with Suzaku on 2005 September 22-23, for a gross time span of ∼1 day.The source was detected over a wide and continuous energy range of 0.7-300 keV, with an intensity of ∼50 mCrab in the 1.5-12 keV band. At an assumed distance of 3.2 kpc, the 0.7-300 keV luminosity is calculated to be ∼ 4.4 × 10 36 ergs s-1. The source was in a typical low/hard state, since its overall spectrum was dominated by a power-law component with a photon index of ∼1.7. The source intensity gradually decreased by 20% during the observation, involving little spectral changes above ∼3 keV. However, at softer energies, the amplitude of variability was somewhat enhanced. This indicates the presence of an independent soft component. The spectra in the hard energy band reveal a high-energy spectral cutoff, with an e-folding energy of ∼200 keV which is suggested to be higher than those observed from typical black hole binaries in the low/hard state.
|ジャーナル||European Space Agency, (Special Publication) ESA SP|
|出版ステータス||Published - 2006 7月|
|イベント||6th Integral Workshop - The Obscured Universe - Moscow, Russian Federation|
継続期間: 2006 7月 2 → 2006 7月 8
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