[vsnet-grb-info 12003] XRF 120626B: MAXI/GSC detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13392
SUBJECT: XRF 120626B: MAXI/GSC detection
DATE:    12/06/28 09:12:17 GMT
FROM:    Motoko Suzuki at RIKEN  <motoko at crab.riken.jp>

Y. Nakano (AGU), H. Negoro (Nihon U.),  
M. Serino, T. Mihara, M. Sugizaki,T. Yamamoto, J. Sugimoto, M. Matsuoka (RIKEN), 
S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa (JAXA),
N. Kawai, M. Morii, R. Usui, K. Ishikawa (Tokyo Tech),
A. Yoshida (AGU),
H. Tsunemi, M. Kimura (Osaka U.), 
M. Nakajima, M. Asada, H. Sakakibara, N. Serita (Nihon U.), 
Y. Ueda, K. Hiroi, M. Shidatsu, R. Sato (Kyoto U.),
Y. Tsuboi, M. Higa (Chuo U.)
M. Yamauchi, Y. Nishimura, T. Hanayama, K. Yoshidome (Miyazaki U.), 
K. Yamaoka (Waseda U.) report on behalf of the MAXI team:

At the scan transit centered at UT 2012-06-26T13:38:14 (UT),
MAXI/GSC detected a short X-ray transient lasted at least for 27 seconds 
within the 45 seconds triangular transit response of MAXI/GSC.
Judging from its high galactic latitude (+47deg) and spectral hardness ratio, 
this transient is probably an X-ray flash.

Assuming that the source flux was constant over the transit, 
we obtain the source position at

(R.A., Dec) = (175.77deg,+68.50deg) = (11 43 04, +68 30 00)(J2000)

which has a statistical uncertainty of 30 arcmin at the 90% confidence limit 
and an additional systematic uncertainty of 6 arcmin (90% containment radius).

The burst was bright in 2-4 keV band.
The flux of the source was 80 +- 20 mCrab (2-4 keV).

There was no significant detection at the transit location in the
previous and the following orbits (92 min before and after the detection) 
with an upper limit of 20 mCrab.