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arXiv · 1109.6069

Long-term Monitoring of the Black Hole Binary GX 339-4 in the High/Soft State during the 2010 Outburst with MAXI/GSC

Megumi Shidatsu·Yoshihiro Ueda·Satoshi Nakahira·Hitoshi Negoro·Kazutaka Yamaoka·Mutsumi Sugizaki·Kazuo Hiroi·Nobuyuki Kawai·Tatehiro Mihara·Masaru Matsuoka·Masashi Kimura·Masaki Ishikawa·Naoki Isobe·Hiroki Kitayama·Mitsuhiro Kohama·Takanori Matsumura·Mikio Morii·Yujin E. Nakagawa·Motoki Nakajima·Motoko Serino·Tetsuya Sootome·Kousuke Sugimori·Fumitoshi Suwa·Takahiro Toizumi·Hiroshi Tomida·Yohko Tsuboi·Hiroshi Tsunemi·Shiro Ueno·Ryuichi Usui·Takayuki Yamamoto·Kyohei Yamazaki·Atsumasa Yoshida
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Abstract

We present the results of monitoring the Galactic black hole candidate GX 339-4 with the Monitor of All-sky X-ray Image (MAXI) / Gas Slit Camera (GSC) in the high/soft state during the outburst in 2010. All the spectra throughout the 8-month period are well reproduced with a model consisting of multi-color disk (MCD) emission and its Comptonization component, whose fraction is <= 25% in the total flux. In spite of the flux variability over a factor of 3, the innermost disk radius is constant at R_in = 61 +/- 2 km for the inclination angle of i = 46 deg and the distance of d=8 kpc. This R_in value is consistent with those of the past measurements with Tenma in the high/soft state. Assuming that the disk extends to the innermost stable circular orbit of a non-spinning black hole, we estimate the black hole mass to be M = 6.8 +/- 0.2 M_sun for i = 46 deg and d = 8 kpc, which is consistent with that estimated from the Suzaku observation of the previous low/hard state. Further combined with the mass function, we obtain the mass constraint of 4.3 M_sun < M < 13.3 M_sun for the allowed range of d = 6-15 kpc and i < 60 deg. We also discuss the spin parameter of the black hole in GX 339-4 by applying relativistic accretion disk models to the Swift/XRT data.

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Megumi Shidatsu, Yoshihiro Ueda, Satoshi Nakahira, Hitoshi Negoro, Kazutaka Yamaoka, Mutsumi Sugizaki, Kazuo Hiroi, Nobuyuki Kawai, Tatehiro Mihara, Masaru Matsuoka, Masashi Kimura, Masaki Ishikawa, Naoki Isobe, Hiroki Kitayama, Mitsuhiro Kohama, Takanori Matsumura, Mikio Morii, Yujin E. Nakagawa, Motoki Nakajima, Motoko Serino, Tetsuya Sootome, Kousuke Sugimori, Fumitoshi Suwa, Takahiro Toizumi, Hiroshi Tomida, Yohko Tsuboi, Hiroshi Tsunemi, Shiro Ueno, Ryuichi Usui, Takayuki Yamamoto, Kyohei Yamazaki, Atsumasa Yoshida. 2011-09-28. Long-term Monitoring of the Black Hole Binary GX 339-4 in the High/Soft State during the 2010 Outburst with MAXI/GSC. https://doi.org/10.1093/pasj%2F63.sp3.s803

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