MAXI/GSC observations of GRBs and X-ray flashes

Author: Nobuyuki Kawai

Abstract: We present the observations of GRBs by MAXI, an all-sky X-ray monitor on the ISS. While the instantaneous field of view of MAXI/GSC is rather small (3 deg × 160 deg), it is detecting GRBs at a rate of about one per month in the energy range of 2-20 keV. Among the events detected by MAXI, about one third were also detected by other instruments like Swift/BAT or Fermi/GBM. Others tend to have softer spectra and lower X-ray fluxes. Some of them would not trigger other missions. There is evidence for additional untriggered short transients in the MAXI data, suggesting presence of a population of soft underluminous extragalactic events.