Abstract
We report on the results from Suzaku observations of the Galactic black hole X-ray binary H1743-322 in the low/hard state during its outburst in 2012 October. We appropriately take into account the effects of dust scattering to accurately analyze the X-ray spectra. The time-averaged spectra in the 1-200 keV band are dominated by a hard power-law component of a photon index of ≈1.6 with a high-energy cutoff at ≈60 keV, which is well described with the Comptonization of the disk emission by the hot corona. We estimate the inner disk radius from the multi-color disk component, and find that it is 1.3-2.3 times larger than the radius in the high/soft state. This suggests that the standard disk was not extended to the innermost stable circular orbit. A reflection component from the disk is detected with R = Ω/2π ≈ 0.6 (Ω is the solid angle). We also successfully estimate the stable disk component independent of the time-averaged spectral modeling by analyzing short-term spectral variability on a ∼1 s timescale. A weak low-frequency quasi-periodic oscillation at 0.1-0.2 Hz is detected, whose frequency is found to correlate with the X-ray luminosity and photon index. This result may be explained by the evolution of the disk truncation radius.
| Original language | English |
|---|---|
| Article number | 100 |
| Journal | Astrophysical Journal |
| Volume | 789 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2014 Jul 10 |
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Keywords
- accretion, accretion disks
- black hole physics
- X-rays: binaries
- X-rays: individual (H1743-322)
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
Spectral and timing properties of the black hole x-ray binary h1743-322 in the low/hard state studied with Suzaku. / Shidatsu, M.; Ueda, Y.; Yamada, S.; Done, C.; Hori, T.; Yamaoka, K.; Kubota, Aya; Nagayama, T.; Moritani, Y.
In: Astrophysical Journal, Vol. 789, No. 2, 100, 10.07.2014.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Spectral and timing properties of the black hole x-ray binary h1743-322 in the low/hard state studied with Suzaku
AU - Shidatsu, M.
AU - Ueda, Y.
AU - Yamada, S.
AU - Done, C.
AU - Hori, T.
AU - Yamaoka, K.
AU - Kubota, Aya
AU - Nagayama, T.
AU - Moritani, Y.
PY - 2014/7/10
Y1 - 2014/7/10
N2 - We report on the results from Suzaku observations of the Galactic black hole X-ray binary H1743-322 in the low/hard state during its outburst in 2012 October. We appropriately take into account the effects of dust scattering to accurately analyze the X-ray spectra. The time-averaged spectra in the 1-200 keV band are dominated by a hard power-law component of a photon index of ≈1.6 with a high-energy cutoff at ≈60 keV, which is well described with the Comptonization of the disk emission by the hot corona. We estimate the inner disk radius from the multi-color disk component, and find that it is 1.3-2.3 times larger than the radius in the high/soft state. This suggests that the standard disk was not extended to the innermost stable circular orbit. A reflection component from the disk is detected with R = Ω/2π ≈ 0.6 (Ω is the solid angle). We also successfully estimate the stable disk component independent of the time-averaged spectral modeling by analyzing short-term spectral variability on a ∼1 s timescale. A weak low-frequency quasi-periodic oscillation at 0.1-0.2 Hz is detected, whose frequency is found to correlate with the X-ray luminosity and photon index. This result may be explained by the evolution of the disk truncation radius.
AB - We report on the results from Suzaku observations of the Galactic black hole X-ray binary H1743-322 in the low/hard state during its outburst in 2012 October. We appropriately take into account the effects of dust scattering to accurately analyze the X-ray spectra. The time-averaged spectra in the 1-200 keV band are dominated by a hard power-law component of a photon index of ≈1.6 with a high-energy cutoff at ≈60 keV, which is well described with the Comptonization of the disk emission by the hot corona. We estimate the inner disk radius from the multi-color disk component, and find that it is 1.3-2.3 times larger than the radius in the high/soft state. This suggests that the standard disk was not extended to the innermost stable circular orbit. A reflection component from the disk is detected with R = Ω/2π ≈ 0.6 (Ω is the solid angle). We also successfully estimate the stable disk component independent of the time-averaged spectral modeling by analyzing short-term spectral variability on a ∼1 s timescale. A weak low-frequency quasi-periodic oscillation at 0.1-0.2 Hz is detected, whose frequency is found to correlate with the X-ray luminosity and photon index. This result may be explained by the evolution of the disk truncation radius.
KW - accretion, accretion disks
KW - black hole physics
KW - X-rays: binaries
KW - X-rays: individual (H1743-322)
UR - http://www.scopus.com/inward/record.url?scp=84903312610&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84903312610&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/789/2/100
DO - 10.1088/0004-637X/789/2/100
M3 - Article
VL - 789
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 100
ER -