MAXI Monitoring of Crab Pulsar during the GeV Gamma-ray Flare on September 2010

We report on the MAXI GSC X-ray monitoring of the Crab nebula and pulsar during the GeV gamma-ray flare on 2010 September detected by AGILE and Fermi-LAT. There were no significant variations on the pulse-phase-averaged and pulsed fluxes during the gamma-ray flare. The pulse profile also showed no significant change during the period. The upper limits on the variation of the pulse-phase-averaged and pulsed fluxes on MJD 55457.5-55462.5 in the 4-10 keV band are 1% and 19% at the 90% confidence limit of the statistical uncertainty, respectively. Here, the measured fluxes include a 2% systematic uncertainty at the 1-σ limit due to the error on the instrument calibration. The lack of variations in the pulsed component in multi-wavelength range (radio, soft X-ray, hard X-ray, and gamma-ray) supports the nebula origin for the gamma-ray flare.