MAXI/GSC detection of an X-ray activity from GX 339-4
K. Yamaoka (AGU), M. Sugizaki (RIKEN), S. Nakahira (AGU), T. Mihara, M. Kohama, Y. E. Nakagawa, T. Yamamoto (RIKEN), M. Matsuoka, K. Kawasaki, S. Ueno, H. Tomida, M. Suzuki, M. Ishikawa (JAXA), N. Kawai, M. Morii, K. Sugimori (Tokyo Tech.), A. Yoshida (AGU), H. Tsunemi, M. Kimura (Osaka U.), H. Negoro, M. Nakajima, R. Ishiwata, S. Miyoshi, H. Ozawa (Nihon U.), Y. Ueda, N. Isobe, S. Eguchi, K. Hiroi (Kyoto U.), and A. Daikyuji (Univ. of Miyazaki), on behalf of the MAXI team
MAXI/GSC has been detecting an X-ray activity of a black hole candidate, GX 339-4, since 2010-Jan-03 (MJD 55199). The flux averaged per day in the 4-10 keV band was almost constant at about 17 mCrab from Jan-03 to Jan-07 and 26 +/- 5 mCrab on Jan-08. The detection on Jan-02 was marginal because the source was located at the edge of the sensitivity gap of the GSC X-ray detectors. The Swift/BAT hard X-ray monitor also shows an increase in the hard X-ray flux in the 15-50 keV range. Follow-up multi-wavelength observations are encouraged.

The MAXI lightcurve and image of the source are updated daily at the following URL: http://maxi.riken.jp/sourcelist.html
x-ray,binary,black hole,transient