[vsnet-grb-info 13490] GRB 130606B: AGILE-MCAL observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14823
SUBJECT: GRB 130606B: AGILE-MCAL observation
DATE:    13/06/08 07:52:59 GMT
FROM:    Martino Marisaldi at INAF-IASF  <marisaldi at iasfbo.inaf.it>

M. Marisaldi, F. Fuschino (INAF/IASF-Bo), F. Verrecchia, C. Pittori (ASDC and INAF/OAR), A. Giuliani (INAF/IASF-Mi), F. Longo (University of Trieste and INFN Trieste), F. Lucarelli (ASDC and INAF/OAR), E. Del Monte, F. Lazzarotto, I. Donnarumma, Y. Evangelista, M. Feroci, L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda (INAF/IAPS Rome), G. Barbiellini, (INFN Trieste), A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti, V. Fioretti, M. Galli (INAF/IASF-Bo), A. Chen, S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF-Mi), M. Cardillo, E. Striani, M. Tavani (INAF/IAPS Rome, and Univ. Roma Tor Vergata), A. Argan, G. Piano, S.
Sabatini, V. Vittorini (INAF/IAPS Rome), G. Pucella (ENEA Frascati), A. Pellizzoni, A. Trois (INAF/OA Cagliari), M. Pilia (ASTRON), S. Vercellone (INAF/IASF-Pa), P. W. Cattaneo, A. Rappoldi (INFN Pavia), A. Morselli, P. Picozza (INFN Roma-2), M. Prest, E. Vallazza (Universita` 
dell'Insubria), S. Colafrancesco (INAF/OAR and WITS), P. Lipari, D. Zanello (INFN Roma-1), P. Giommi (ASI), and G. Valentini (ASI),
on behalf of the AGILE Team, report:

"The long hard bright GRB 130606B, observed in gamma-rays by Fermi-LAT (Vianello et al., GCN 14795), Fermi-GBM (Yu et al., GCN 14801) and Konus-Wind (Golenetskii et al., GCN 14803), triggered AGILE-MCAL, sensitive in the range 0.4 - 100 MeV, at 11:55:33 UT (T0).

The light curve above 400 keV shows three main peaks between T0 and T0 + 20 s, followed by two less bright peaks at T0 + 40 s and T0 + 50 s.
The time-integrated spectrum measured between T0 and T0 + 20 s can be fit in the energy range 0.5 - 20 MeV with a simple power law with photon index -2.15 +/- 0.03 and reduced chi-squared 1.67 (46 d.o.f). As observed by MCAL the burst fluence in the same energy range and time interval is (1.62 +/- 0.05)E-04 erg/cm^2. All quoted errors are at 90% confidence levels.

The burst was 118 degrees off-axis with respect to the AGILE GRID pointing direction at T0, from a sky region not accessible to the GRID.
This measurement was obtained with AGILE observing a large portion of the sky in spinning mode."