MAXI/GSC detection of a short X-ray transient MAXI J1631-639
ATel #3316; H. Negoro (Nihon U.), K. Yamaoka (AGU), S. Nakahira (RIKEN), M. Nakajima, F. Suwa (Nihon U.), T. Mihara, M. Sugizaki, M. Serino, T. Yamamoto, T. Sootome, M. Matsuoka (RIKEN), S. Ueno, H. Tomida, M. Kohama, M. Ishikawa (JAXA), N. Kawai, M. Morii, K. Sugimori, R. Usui, T. Toizumi (Tokyo Tech), A. Yoshida (AGU), H. Tsunemi, M. Kimura, H. Kitayama (Osaka U.), Y. Ueda, K. Hiroi, M. Shidatsu (Kyoto U.), Y. Tsuboi, T. Matsumura, K. Yamazaki (Chuo U.) report on behalf of the MAXI team
on 30 Apr 2011; 01:21 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Tatehiro Mihara (mihara@crab.riken.jp)
Subjects: X-ray, Transient
At 2011-04-29 16:12:38 UT (= MJD 55680.6754), the MAXI/GSC alert system
triggered an X-ray transient during one scan transit located at:
(R.A., Dec) = (+247.83 deg, -63.95 deg) = (16 31 19.2, -63 57 00) (J2000)
with a systematic uncertainty of 0.2 deg. The flux was 122 +/- 15 mCrab in 2-20 keV.
There is no known bright X-ray source in the error circle. The GSC spectrum
in the 2-20 keV range is roughly explained by a power law with the photon index of about 1.7.
No significant emission was detected during the following three scan transits on 17:44, 19:15, and 20:47 (UT).
The source is maybe a short-lived X-ray transient such as gamma-ray burst
and X-ray burst. We tentatively refer this transient as MAXI J1631-639.
Follow-up observations are strongly encouraged.
