X-Ray and Near-Infrared Observations of GX 339−4 in the Low/Hard State with Suzaku and IRSF

DOI DOI PDF 被引用文献16件 オープンアクセス
  • Megumi Shidatsu
    1Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 shidatsu@kusastro.kyoto-u.ac.jp  ueda@kusastro.kyoto-u.ac.jp
  • Yoshihiro Ueda
    1Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 shidatsu@kusastro.kyoto-u.ac.jp  ueda@kusastro.kyoto-u.ac.jp
  • Fumie Tazaki
    1Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 shidatsu@kusastro.kyoto-u.ac.jp  ueda@kusastro.kyoto-u.ac.jp
  • Tatsuhito Yoshikawa
    1Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 shidatsu@kusastro.kyoto-u.ac.jp  ueda@kusastro.kyoto-u.ac.jp
  • Takahiro Nagayama
    2Department of Astrophysics, Nagoya University, Furocho, Chikusaku, Nagoya 464-8602
  • Tetsuya Nagata
    1Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 shidatsu@kusastro.kyoto-u.ac.jp  ueda@kusastro.kyoto-u.ac.jp
  • Nagisa Oi
    3Department of Astronomy, Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-8588
  • Kazutaka Yamaoka
    4Department of Physics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 229-8558
  • Hiromitsu Takahashi
    5Department of Physical Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526
  • Aya Kubota
    6Department of Electronic Information Systems, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama 337-8570
  • Jean Cottam
    7Exploration of the Universe Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
  • Ronald Remillard
    8Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02138, USA
  • Hitoshi Negoro
    9Department of Physics, Nihon University, 1-8-14 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308

この論文をさがす

説明

<jats:p>X-ray and near-infrared ( $J$ – $H$ – $K_{\rm s}$ ) observations of the galactic black-hole binary GX 339 $-$ 4 in the low/hard state were performed with Suzaku and IRSF in 2009 March. The spectrum in the 0.5–300 keV band is dominated by thermal Comptonization of multicolor disk photons, with a small contribution from a direct disk component, indicating that the inner disk is almost fully covered by hot corona with an electron temperature of $\approx$ 175 keV. The Comptonizing corona has at least two optical depths, $\tau$  $\approx$ 1, 0.4. Analysis of the iron-K line profile yields an inner-disk radius of (13.3 $^{+6.4}_{-6.0}$ ) $\ R_{\rm g}$ ( $\ R_{\rm g}$ represents the gravitational radius $GM/c^2$ ), with the best-fit inclination angle of $\approx$ 50 $^\circ$ . This radius is consistent with that estimated from the continuum fit by assuming the conservation of photon numbers in Comptonization. Our results suggest that the standard disk of GX 339 $-$ 4 is likely truncated before reaching the innermost stable circular orbit (for a non-rotating black hole) in the low/hard states at $\sim\ $ 1% of the Eddington luminosity. The one-day averaged near-infrared light curves are found to be correlated with hard X-ray flux with $F_{\rm Ks}$  $\propto$  $F_{\rm X}^{0.45}$ . The flatter near-infrared $\nu F_{\nu}$ spectrum than the radio one suggests that the optically thin synchrotron radiation from the compact jets dominates the near-infrared flux. Based on a simple analysis, we estimate the magnetic field and size of the jet base to be 5 $\times$ 10 $^{4}\ $ G and 6 $\times$ 10 $^{8}\ $ cm, respectively. The synchrotron self Compton component is estimated to be approximately 0.4% of the total X-ray flux.</jats:p>

収録刊行物

被引用文献 (16)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ