Suzaku results on cygnus X-1 in the low/hard State

Kazuo Makishima, Hiromitsu Takahashi, Shin'ya Yamada, Chris Done, Aya Kubota, Tadayasu Dotani, Ken Ebisawa, Takeshi Itoh, Shunji Kitamoto, Hitoshi Negoro, Yoshihiro Ueda, Kazutaka Yamaoka

研究成果: Article

88 引用 (Scopus)

抄録

The black-hole binary Cygnus X-1 was observed for 17 ks with the Suzaku X-ray observatory in 2005 October, while it was in a low/hard state with a 0.7-300keV luminosity of 4.6 × 1037 erg s-1. The XIS and HXD spectra, spanning 0.7-400 keV, were reproduced successfully, incorporating a cool accretion disk and a hot Comptonizing corona. The corona is characterized by an electron temperature of ∼ 100 keV, and two optical depths of ∼0.4 and ∼ 1.5, which account for the softer and harder continua, respectively. The disk has an innermost temperature of ∼ 0.2keV, and is thought to protrude half way into the corona. The disk not only provides seed photons to the Compton cloud, but also produces a soft spectral excess, a mild reflection hump, and a weakly broadened iron line. A comparison with the Suzaku data on GRO J1655-40 reveals several interesting spectral differences, which can mostly be attributed to inclination effects, assuming that the disk has a flat geometry while the corona is grossly spherical. An intensity-sorted spectroscopy indicates that the continuum becomes less Comptonized when the source flares up on time scales of 1-200 s, while the underlying disk remains unchanged.

元の言語English
ページ(範囲)585-604
ページ数20
ジャーナルPublications of the Astronomical Society of Japan
60
発行部数3
出版物ステータスPublished - 2008

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coronas
corona
continuums
accretion disks
erg
optical thickness
optical depth
flares
inclination
seeds
observatories
observatory
temperature
spectroscopy
accretion
luminosity
electron energy
timescale
seed
iron

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

これを引用

Makishima, K., Takahashi, H., Yamada, S., Done, C., Kubota, A., Dotani, T., ... Yamaoka, K. (2008). Suzaku results on cygnus X-1 in the low/hard State. Publications of the Astronomical Society of Japan, 60(3), 585-604.

Suzaku results on cygnus X-1 in the low/hard State. / Makishima, Kazuo; Takahashi, Hiromitsu; Yamada, Shin'ya; Done, Chris; Kubota, Aya; Dotani, Tadayasu; Ebisawa, Ken; Itoh, Takeshi; Kitamoto, Shunji; Negoro, Hitoshi; Ueda, Yoshihiro; Yamaoka, Kazutaka.

:: Publications of the Astronomical Society of Japan, 巻 60, 番号 3, 2008, p. 585-604.

研究成果: Article

Makishima, K, Takahashi, H, Yamada, S, Done, C, Kubota, A, Dotani, T, Ebisawa, K, Itoh, T, Kitamoto, S, Negoro, H, Ueda, Y & Yamaoka, K 2008, 'Suzaku results on cygnus X-1 in the low/hard State', Publications of the Astronomical Society of Japan, 巻. 60, 番号 3, pp. 585-604.
Makishima K, Takahashi H, Yamada S, Done C, Kubota A, Dotani T その他. Suzaku results on cygnus X-1 in the low/hard State. Publications of the Astronomical Society of Japan. 2008;60(3):585-604.
Makishima, Kazuo ; Takahashi, Hiromitsu ; Yamada, Shin'ya ; Done, Chris ; Kubota, Aya ; Dotani, Tadayasu ; Ebisawa, Ken ; Itoh, Takeshi ; Kitamoto, Shunji ; Negoro, Hitoshi ; Ueda, Yoshihiro ; Yamaoka, Kazutaka. / Suzaku results on cygnus X-1 in the low/hard State. :: Publications of the Astronomical Society of Japan. 2008 ; 巻 60, 番号 3. pp. 585-604.
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abstract = "The black-hole binary Cygnus X-1 was observed for 17 ks with the Suzaku X-ray observatory in 2005 October, while it was in a low/hard state with a 0.7-300keV luminosity of 4.6 × 1037 erg s-1. The XIS and HXD spectra, spanning 0.7-400 keV, were reproduced successfully, incorporating a cool accretion disk and a hot Comptonizing corona. The corona is characterized by an electron temperature of ∼ 100 keV, and two optical depths of ∼0.4 and ∼ 1.5, which account for the softer and harder continua, respectively. The disk has an innermost temperature of ∼ 0.2keV, and is thought to protrude half way into the corona. The disk not only provides seed photons to the Compton cloud, but also produces a soft spectral excess, a mild reflection hump, and a weakly broadened iron line. A comparison with the Suzaku data on GRO J1655-40 reveals several interesting spectral differences, which can mostly be attributed to inclination effects, assuming that the disk has a flat geometry while the corona is grossly spherical. An intensity-sorted spectroscopy indicates that the continuum becomes less Comptonized when the source flares up on time scales of 1-200 s, while the underlying disk remains unchanged.",
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AU - Yamada, Shin'ya

AU - Done, Chris

AU - Kubota, Aya

AU - Dotani, Tadayasu

AU - Ebisawa, Ken

AU - Itoh, Takeshi

AU - Kitamoto, Shunji

AU - Negoro, Hitoshi

AU - Ueda, Yoshihiro

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