TITLE:   GCN CIRCULAR
NUMBER:  9355
SUBJECT: GRB 090510: Suzaku WAM observation of the prompt emission
DATE:    09/05/14 08:52:46 GMT
FROM:    Norisuke Ohmori at Miyazaki U  <ohmori@astro.miyazaki-u.ac.jp>

N. Ohmori, K. Noda, E. Sonoda, M. Yamauchi, K. Kono, H. Hayashi,
A. Daikyuji, Y. Nishioka (Univ. of Miyazaki),
M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA),
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), Y. E. Nakagawa,
T. Tamagawa (RIKEN), S. Hong (Nihon U.), N. Vasquez (Tokyo Tech.),
T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.),
W. Iwakiri, M. Tashiro, Y. Terada, A. Endo, K. Onda,
T. Sugasahara (Saitama U.), Y. Urata (NCU),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo),
on behalf of the Suzaku WAM team, report:

The short hard GRB 090510 detected by the Fermi-LAT (Swift/BAT trigger
 #351588; Hoversten et al., GCN 9331,Fermi-LAT trigger #263607783;
 Ohno et al., GCN 9334) 
 triggered the Suzaku Wide-band All-sky Monitor (WAM) 
 which covers an energy range of 50 keV - 5 MeV at 00:23:00 UT (=T0).

The observed light curve shows a multi-peaked structure starting at T0-0.1s, 
 ending at T0+0.9s  with a duration (T90) of about 0.33 seconds.
The emissions was clearly detected at least up to 5 MeV.

However, since the incident angle of this burst to the WAM is off-axis, we
 cannot perform a reliable spectral analysis at this moment. 
We are now improving our detector response from such an off-axis direction.

The light curves for this burst are available at:

 http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html