Suzaku observation of X-ray variability in soft state LMCX-1

Shu Koyama; Shin'Ya Yamada; Aya Kubota; Makoto S. Tashiro; Yukikatsu Terada; Kazuo Makishima

doi:10.1093/pasj/psv017

Suzaku observation of X-ray variability in soft state LMCX-1

Shu Koyama, Shin'Ya Yamada, Aya Kubota, Makoto S. Tashiro, Yukikatsu Terada, Kazuo Makishima

Research output: Contribution to journal › Article › peer-review

3 Citations (Scopus)

Abstract

This paper reports the results of Suzaku observation of the spectral variation of the black hole binary LMCX-1 in the soft state. The observation was carried out in 2009 from July 21 to 24. the obtained net count rate was ∼30countss^-1 in the 0.5-50keV band with ∼10% peak-to-peak flux variation. The time-averaged X-ray spectrum cannot be described by a multi-color disk and single Compton component with its reflection, but requires additional Comptonized emissions. This double Compton component model allows a slightly larger inner radius of the multi-color disk, implying a lower spin parameter. Significant spectral evolution was observed above 8keV along with a flux decrease on a timescale of ∼10⁴-10⁵ s. By spectral fitting, we show that this behavior is well explained by changes in the hard Comptonized emission component in contrast to the maintained disk and soft Comptonized emission.

Original language	English
Article number	46
Journal	Publications of the Astronomical Society of Japan
Volume	67
Issue number	3
DOIs	https://doi.org/10.1093/pasj/psv017
Publication status	Published - 2015 Apr 8

Keywords

accretion, accretion disks-black hole physics-X-rays
individual (LMC X-1)

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1093/pasj/psv017

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title = "Suzaku observation of X-ray variability in soft state LMCX-1",

abstract = "This paper reports the results of Suzaku observation of the spectral variation of the black hole binary LMCX-1 in the soft state. The observation was carried out in 2009 from July 21 to 24. the obtained net count rate was ∼30countss-1 in the 0.5-50keV band with ∼10% peak-to-peak flux variation. The time-averaged X-ray spectrum cannot be described by a multi-color disk and single Compton component with its reflection, but requires additional Comptonized emissions. This double Compton component model allows a slightly larger inner radius of the multi-color disk, implying a lower spin parameter. Significant spectral evolution was observed above 8keV along with a flux decrease on a timescale of ∼104-105 s. By spectral fitting, we show that this behavior is well explained by changes in the hard Comptonized emission component in contrast to the maintained disk and soft Comptonized emission.",

keywords = "accretion, accretion disks-black hole physics-X-rays, individual (LMC X-1)",

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AU - Koyama, Shu

AU - Yamada, Shin'Ya

AU - Kubota, Aya

AU - Tashiro, Makoto S.

AU - Terada, Yukikatsu

AU - Makishima, Kazuo

PY - 2015/4/8

Y1 - 2015/4/8

N2 - This paper reports the results of Suzaku observation of the spectral variation of the black hole binary LMCX-1 in the soft state. The observation was carried out in 2009 from July 21 to 24. the obtained net count rate was ∼30countss-1 in the 0.5-50keV band with ∼10% peak-to-peak flux variation. The time-averaged X-ray spectrum cannot be described by a multi-color disk and single Compton component with its reflection, but requires additional Comptonized emissions. This double Compton component model allows a slightly larger inner radius of the multi-color disk, implying a lower spin parameter. Significant spectral evolution was observed above 8keV along with a flux decrease on a timescale of ∼104-105 s. By spectral fitting, we show that this behavior is well explained by changes in the hard Comptonized emission component in contrast to the maintained disk and soft Comptonized emission.

AB - This paper reports the results of Suzaku observation of the spectral variation of the black hole binary LMCX-1 in the soft state. The observation was carried out in 2009 from July 21 to 24. the obtained net count rate was ∼30countss-1 in the 0.5-50keV band with ∼10% peak-to-peak flux variation. The time-averaged X-ray spectrum cannot be described by a multi-color disk and single Compton component with its reflection, but requires additional Comptonized emissions. This double Compton component model allows a slightly larger inner radius of the multi-color disk, implying a lower spin parameter. Significant spectral evolution was observed above 8keV along with a flux decrease on a timescale of ∼104-105 s. By spectral fitting, we show that this behavior is well explained by changes in the hard Comptonized emission component in contrast to the maintained disk and soft Comptonized emission.

KW - accretion, accretion disks-black hole physics-X-rays

KW - individual (LMC X-1)

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Suzaku observation of X-ray variability in soft state LMCX-1

Abstract

Keywords

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