Result of 15yr timing of PSR J0007+7303

Yu, Zhixiang

PSR J0007+7303 is the first gamma-ray pulsar discovered by the Fermi-LAT telescope， and have been detected three glitches in previous work. In this paper， we present the 15 years of timing results of this pulsar using the Fermi-LAT data. Using the traditional pulsar timing technical， we detected a total of nine glitches， two of which are small and the rest are large. These two small glitches are newly discovered between the three glitches that have already been reported. And no exponential recovery behavior was found after these glitches. The intervals between each glitch are about 1 to 2 years. We performed a detailed parametric description of all the glitches and analysed the changes in the photon integral pulse profile after each glitch， and found that there are different degree of integral pulse profiles for each time period. We also studied the effect of these glitches on the flux of gamma-ray radiation. We discussed the nature of the neutron star interior based on these glitch phenomena.

Keywords: pulsar: individual (PSR J0007+7303) – gamma-ray – glitch – timing