TY - JOUR
T1 - A spectral study of the black hole candidate XTE J1752-223 in the high/soft state with MAXI, Suzaku, and Swift
AU - Nakahira, Satoshi
AU - Koyama, Shu
AU - Ueda, Yoshihiro
AU - Yamaoka, Kazutaka
AU - Sugizaki, Mutsumi
AU - Mihara, Tatehiro
AU - Matsuoka, Masaru
AU - Yoshida, Atsumasa
AU - Makishima, Kazuo
AU - Ebisawa, Ken
AU - Kubota, Aya
AU - Yamada, Shin'ya
AU - Negoro, Hitoshi
AU - Hiroi, Kazuo
AU - Ishikawa, Masaki
AU - Kawai, Nobuyuki
AU - Kimura, Masashi
AU - Kitayama, Hiroki
AU - Kohama, Mitsuhiro
AU - Matsumura, Takanori
AU - Morii, Mikio
AU - Nakajima, Motoki
AU - Serino, Motoko
AU - Shidatsu, Megumi
AU - Sootome, Tetsuya
AU - Sugimori, Kousuke
AU - Suwa, Fumitoshi
AU - Tomida, Hiroshi
AU - Tsuboi, Yoko
AU - Tsunemi, Hiroshi
AU - Ueno, Shiro
AU - Usui, Ryuichi
AU - Yamamoto, Takayuki
AU - Yamazaki, Kyohei
AU - Tashiro, Makoto S.
AU - Terada, Yukikatsu
AU - Seta, Hiromi
PY - 2012/2/25
Y1 - 2012/2/25
N2 - We report on an X-ray spectral analysis of the black hole candidate XTE J1752-223 in the 2009-2010 outburst, utilizing data obtained with the MAXI/Gas Slit Camera (GSC), the Swift/XRT, and Suzaku, which work comple-mentarily. As already reported by Nakahira et al. (2010, PASJ, 62, L27), MAXI monitored the source continuously throughout the entire outburst for about eight months. All of the MAXI/GSC energy spectra in the high/soft state, lasting for 2 months, are well represented by a multi-color disk plus power-law model. The innermost disk temperature changed from ∼0.7 keV to ∼0.4 keV and the disk flux decreased by an order of magnitude. Nevertheless, the innermost radius is constant at ∼41 D3.5(cos i)-1/2km, where D 3.5 is the source distance in units of 3.5kpc and i the inclination. The multi-color disk parameters obtained with the MAXI/GSC are consistent with those with the Swift/XRT and Suzaku. The Suzaku data also suggest a possibility that the disk emission is slightly Comptonized, which could account for broad iron-K features reported previously. Assuming that the obtained innermost radius represents the innermost stable circular orbit for a non-rotating black hole, we estimate the mass of the black hole to be 5.51 ± 0.28 M ⊙ D3.5(cos -1/2, where the correction for the stress-free inner boundary condition and color hardening factor of 1.7 are taken into account. If the inclination is less than 49°, as suggested from radio monitoring of transient jets, and the soft-to-hard transition in 2010 April occurred at 1%-4% of Eddignton luminosity, the fitting of the Suzaku spectra with a relativistic accretion-disk model derives constraints on the mass and the distance to be 3.1-55M⊙ and 2.3-22 kpc, respectively. This confirms that the compact object in XTE J1752-223 is a black hole.
AB - We report on an X-ray spectral analysis of the black hole candidate XTE J1752-223 in the 2009-2010 outburst, utilizing data obtained with the MAXI/Gas Slit Camera (GSC), the Swift/XRT, and Suzaku, which work comple-mentarily. As already reported by Nakahira et al. (2010, PASJ, 62, L27), MAXI monitored the source continuously throughout the entire outburst for about eight months. All of the MAXI/GSC energy spectra in the high/soft state, lasting for 2 months, are well represented by a multi-color disk plus power-law model. The innermost disk temperature changed from ∼0.7 keV to ∼0.4 keV and the disk flux decreased by an order of magnitude. Nevertheless, the innermost radius is constant at ∼41 D3.5(cos i)-1/2km, where D 3.5 is the source distance in units of 3.5kpc and i the inclination. The multi-color disk parameters obtained with the MAXI/GSC are consistent with those with the Swift/XRT and Suzaku. The Suzaku data also suggest a possibility that the disk emission is slightly Comptonized, which could account for broad iron-K features reported previously. Assuming that the obtained innermost radius represents the innermost stable circular orbit for a non-rotating black hole, we estimate the mass of the black hole to be 5.51 ± 0.28 M ⊙ D3.5(cos -1/2, where the correction for the stress-free inner boundary condition and color hardening factor of 1.7 are taken into account. If the inclination is less than 49°, as suggested from radio monitoring of transient jets, and the soft-to-hard transition in 2010 April occurred at 1%-4% of Eddignton luminosity, the fitting of the Suzaku spectra with a relativistic accretion-disk model derives constraints on the mass and the distance to be 3.1-55M⊙ and 2.3-22 kpc, respectively. This confirms that the compact object in XTE J1752-223 is a black hole.
KW - Accretion disks
KW - Black hole physics
KW - Stars: individual (XTE J1752-223)
KW - X-rays: stars
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U2 - 10.1093/pasj/64.1.13
DO - 10.1093/pasj/64.1.13
M3 - Article
AN - SCOPUS:84863287542
VL - 64
JO - Publication of the Astronomical Society of Japan
JF - Publication of the Astronomical Society of Japan
SN - 0004-6264
IS - 1
ER -