{
  "bibcode": "2007GCN..6854....1G",
  "body": "Galante N. (MPI/Muenchen), Garczarczyk M. (MPI/Muenchen),\nGaug M. (IAC/Tenerife), Bastieri D. (U. Padova), Longo F. (INFN/Trieste)\nand Scapin V. (U. Udine), for the MAGIC Collaboration\n\nThe MAGIC Imaging Atmospheric Cherenkov Telescope performed a follow-up\nobservation of the SWIFT/BAT burst GRB070920A (GCN circular 6805,\nGrupe D., et al.). We received the GCN alert at T0+539s. The data taking\nby MAGIC started at T0+690s, 2.5 minutes after the alert income.\nWe observed the sky positon for 36min spanning a zenith angle\nin the range 53-50 degrees.\n\nNo evidence for VHE gamma-ray emission above the analysis threshold of\nabout 250 GeV was found. A preliminary analysis, taking advantage\nfor the first time of the fast 2GHz digitalization from the\nnew data acquisition system, and for the hypothesis of\nsteady emission and assumption of a differential photon\nspectral index of -2.5, yields the following 95% CL differential flux\nupper limits (inc. 30% systematic error on the efficiency):\n\nE(225-300 GeV)  : 7.1 x 10^(-8) erg/cm^2\nE(300-400 GeV)  : 4.6 x 10^(-8) erg/cm^2\nE(400-1000 GeV) : 2.2 x 10^(-8) erg/cm^2\nE(1-10 TeV)     : 0.53 x 10^(-8) erg/cm^2\n\nThe upper limits correspond to the time period between T0+690s and\nT0+2490s. We can also exclude emission of a constant flux during our observation\nin any 100s time bin higher than:\n\nE(225-300 GeV)  : 1.9 x 10^(-7) erg/cm^2\nE(300-400 GeV)  : 1.0 x 10^(-7) erg/cm^2\nE(400-1000 GeV) : 2.4 x 10^(-8) erg/cm^2\n\nThis message can be cited.",
  "circularId": 6854,
  "createdOn": 1191658881000,
  "email": "galante@mppmu.mpg.de",
  "subject": "GRB070920A: MAGIC telescope GeV observation",
  "submitter": "Nicola Galante at MPI,Muenchen  <galante@mppmu.mpg.de>",
  "eventId": "GRB 070920A"
}