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Suzaku observation of the black hole transient 4U1630–472: discovery of absorption lines

Published online by Cambridge University Press:  01 August 2006

Aya Kubota
Affiliation:
Inst. of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 email: aya@crab.riken.jp
Tadayasu Dotani
Affiliation:
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510
Jean Cottam
Affiliation:
Exploration of the Universe Div., NASA GSFC, Greenbelt, MD 20771, USA
Taro Kotani
Affiliation:
Department of Physics, Tokyo Tech, 2-12-1 O-okayama, Meguro, Tokyo 152-8551, Japan
Chris Done
Affiliation:
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 Department of Physics, University of Durham, South Road, Durham, DH1 3LE, UK
Yoshihiro Ueda
Affiliation:
Department of Astronomy, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
Andy C. Fabian
Affiliation:
Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK
Tomonori Yasuda
Affiliation:
Department of Physics, Hiroshima Univ., Higashi-Hiroshima, Hiroshima 739-8526
Hiromitsu Takahashi
Affiliation:
Department of Physics, Hiroshima Univ., Higashi-Hiroshima, Hiroshima 739-8526
Yasushi Fukazawa
Affiliation:
Department of Physics, Hiroshima Univ., Higashi-Hiroshima, Hiroshima 739-8526
Kazutaka Yamaoka
Affiliation:
Department of Physics, Aoyama Gakuin University, Sagamihara, Kanagawa 229-8558, Japan
Kazuo Makishima
Affiliation:
Inst. of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 email: aya@crab.riken.jp Department of Physics, Univ. of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
Shinya Yamada
Affiliation:
Department of Physics, Univ. of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
Takayoshi Kohmura
Affiliation:
Physics Department, Kogakuin University 2665-1, Nakano-cho, Hachioji, Tokyo, 192-0015
Lorella Angelini
Affiliation:
Exploration of the Universe Div., NASA GSFC, Greenbelt, MD 20771, USA
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Abstract

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We present the results of six Suzaku observations of the recurrent black hole transient 4U 1630–472 during its decline from its most recent outburst in 2006. All observations show the typical high/soft state spectral shape in the 2–50 keV band, roughly described by an optically thick disk spectrum in the soft energy band plus a weak power-law tail.

The disk temperature decreases from 1.4 keV to 1.2 keV as the flux decreases by a factor 2, consistent with a constant radius as expected for disk-dominated spectra. All the observations reveal significant absorption lines from highly ionized (H-like and He-like) iron Kα at 7.0 keV and 6.7 keV.

The energies of these absorption lines suggest a blue shift with an outflow velocity of ∼1000 km s−1. The H–like iron Kα equivalent width remains approximately constant at ∼30 eV over all the observations, while that of the He–like Kα line increases from 7 eV to 20 eV. Thus the ionization state of the material decreases, as expected from the decline in flux.

The data constrain the velocity dispersion of the absorber to 200–2000 km s−1, and the size of the plasma as ∼1010 cm assuming a source distance of 10 kpc.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2007

References

Boirin, L., Parmar, A. N., Barret, D., Paltani, S., Grindlay, J. E. 2004, A&A, 418, 1061Google Scholar
Kallman, T. R., Angelini, L., Boroson, B., & Cottam, J. 2003, ApJ, 583, 861Google Scholar
Kallman, T. & Bautista, M. 2001, ApJS, 133, 221CrossRefGoogle Scholar
Kubota, A. et al. 2006 PASJ, in pressGoogle Scholar
Kuulkers, E., van der Klis, M., Parmar, A. N. 1997, ApJ, 474, L47CrossRefGoogle Scholar
Kokubun, M. et al. 2006, PASJ, in pressGoogle Scholar
Kotani, T. et al. 2000, ApJ, 539, 413CrossRefGoogle Scholar
Koyama, K. et al. 2006, PASJ, in pressGoogle Scholar
Makishima, K. et al. 1986, ApJ, 308, 635Google Scholar
Miller, J. M. et al. 2006, Nature, 441, 953Google Scholar
Mitsuda, K. et al. 1984, PASJ, 36, 741Google Scholar
Mitsuda, K. et al. 2006, PASJ, in pressGoogle Scholar
Shakura, N. I. & Sunyaev, R. A. 1973, A&A, 24, 337Google Scholar
Sidoli, L., Parmar, A. N., Oosterbroek, T., Lumb, D. 2002, A&A, 385, 940Google Scholar
Takahashi, T. et al. 2006, PASJ, in pressGoogle Scholar
Tanaka, Y., Lewin, W. H. G. 1995, in X-ray Binaries, eds. Lewin, W. H. G., Paradijs, J. van, and Heuvel, W. P. J. van den (Cambridge University Press, Cambridge), p. 126Google Scholar
Ueda, Y. et al. 1998, ApJ, 492, 782Google Scholar
Ueda, Y., Murakami, H., Yamaoka, K., Dotani, T., Ebisawa, K. 2004, ApJ, 609, 325CrossRefGoogle Scholar
Yamaoka, K. et al. 2001, PASJ, 53, 179CrossRefGoogle Scholar