MAXI GSC monitoring of the Crab nebula and pulsar during the GeV gamma-ray flare in September 2010

TL;DR

This study used MAXI GSC X-ray monitoring to investigate the Crab nebula and pulsar during a 2010 gamma-ray flare, finding no significant flux variations and supporting a nebular origin for the flare.

Contribution

First simultaneous X-ray monitoring of the Crab during a gamma-ray flare, providing constraints on flux variations and supporting nebular origin of the flare.

Findings

No significant flux variations detected during the flare.

Pulse profile remained unchanged during the flare.

Results support nebular, not pulsar, origin of the gamma-ray flare.

Abstract

We report on the MAXI GSC X-ray monitoring of the Crab nebula and pulsar during the GeV gamma-ray flare for the period of 2010 September 18-24 (MJD 55457-55463) detected by AGILE and Fermi-LAT. There were no significant variations on the pulse phase averaged and pulsed fluxes during the gamma-ray flare on time scales from 0.5 to 5 days. The pulse profile also showed no significant change during this period. The upper limits on the variations of the pulse phase averaged and pulsed fluxes for the period MJD 55457.5-55462.5 in the 4-10 keV band are derived to be 1 and 19%, respectively, at the 90% confidence limit of the statistical uncertainty. The lack of variations in the pulsed component over the multi-wavelength range (radio, X-ray, hard X-ray, and gamma-ray) supports not the pulsar but the nebular origin for the gamma-ray flare.