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 journalArticle

2 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<sup>-1</sup> 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 ∼10<sup>4</sup>-10<sup>5</sup> 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 languageEnglish
Article number46
JournalPublications of the Astronomical Society of Japan
Volume67
Issue number3
DOIs
Publication statusPublished - 2015 Apr 8

Fingerprint

color
x rays
timescale
radii
rate
parameter

Keywords

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

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Suzaku observation of X-ray variability in soft state LMCX-1. / Koyama, Shu; Yamada, Shin'Ya; Kubota, Aya; Tashiro, Makoto S.; Terada, Yukikatsu; Makishima, Kazuo.

In: Publications of the Astronomical Society of Japan, Vol. 67, No. 3, 46, 08.04.2015.

Research output: Contribution to journalArticle

Koyama, Shu ; Yamada, Shin'Ya ; Kubota, Aya ; Tashiro, Makoto S. ; Terada, Yukikatsu ; Makishima, Kazuo. / Suzaku observation of X-ray variability in soft state LMCX-1. In: Publications of the Astronomical Society of Japan. 2015 ; Vol. 67, No. 3.
@article{d76f1386ae944a23848939693e855e64,
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)",
author = "Shu Koyama and Shin'Ya Yamada and Aya Kubota and Tashiro, {Makoto S.} and Yukikatsu Terada and Kazuo Makishima",
year = "2015",
month = "4",
day = "8",
doi = "10.1093/pasj/psv017",
language = "English",
volume = "67",
journal = "Publication of the Astronomical Society of Japan",
issn = "0004-6264",
publisher = "Astronomical Society of Japan",
number = "3",

}

TY - JOUR

T1 - Suzaku observation of X-ray variability in soft state LMCX-1

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)

UR - http://www.scopus.com/inward/record.url?scp=84930739624&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84930739624&partnerID=8YFLogxK

U2 - 10.1093/pasj/psv017

DO - 10.1093/pasj/psv017

M3 - Article

VL - 67

JO - Publication of the Astronomical Society of Japan

JF - Publication of the Astronomical Society of Japan

SN - 0004-6264

IS - 3

M1 - 46

ER -