The light curve , energy spectra , energetics , and IPN localization of an exceedingly intense short duration hard spectrum burst , GRBÂ 070201 , obtained from Konus-Wind , INTEGRAL ( SPI-ACS ) , and MESSENGER data are presented .
The total fluence of the burst and the peak flux are S = 2.00 _ { -0.26 } ^ { +0.10 } \times 10 ^ { -5 }  erg cm ^ { -2 } and F _ { \mathrm { max } } = 1.61 _ { -0.50 } ^ { +0.29 } \times 10 ^ { -3 }  erg cm ^ { -2 }  s ^ { -1 } .
The IPN error box has an area of 446 square arcminutes and covers the peripheral part of the M31 galaxy .
Assuming that the source of the burst is indeed in M31 at a distance of 0.78 Mpc , the measured values of the fluence S and maximum flux F _ { \mathrm { max } } correspond to a total energy of Q = 1.5 \times 10 ^ { 45 }  erg , and a maximum luminosity L = 1.2 \times 10 ^ { 47 }  erg s ^ { -1 } .
These data are in good agreement with the corresponding characteristics of the previously observed giant flares from other soft gamma repeaters .
The evidence for the identification of this event as a giant flare from a soft gamma repeater in the M31 galaxy is presented .