[vsnet-grb-info 13147] GRB 130427A: SPI-ACS/INTEGRAL observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14484
SUBJECT: GRB 130427A: SPI-ACS/INTEGRAL observations
DATE:    13/04/28 06:38:27 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A. Pozanenko (IKI), P. Minaev (IKI), A. Volnova (IKI) report:

The SPI-ACS detector (> 80 keV) of INTEGRAL observatory was triggered by the 
Swift GRB 130427A  (Maselli et al., GCN 14448) on (UT) T0=07:47:06.36. Light 
curve of the GRB 130427A 
(http://www.isdc.unige.ch/integral/ibas/cgi-bin/ibas_acs_web.cgi) consists 
of the first peak of ~ 1 s duration  which coincides with bright optical 
emission detected by RAPTOR (Wren et al., GCN 14476). This peak is also 
clearly visible in the BAT light curve at ~T0_BAT-51 s ( 
http://gcn.gsfc.nasa.gov/notices_s/554620/BA/ ). Following the first peak 
extremely intense emission was detected coinciding with BAT/Swift and 
Fermi-LAT detection (Zhu et al., GCN 14471). The emission in SPI-ACS 
detector is significantly detectable at least up to 100 s after T0.

The SPI-ACS light curve can be also found at
http://grb.rssi.ru/GRB130427A/GRB130427A_SPI-ACS.png