The Correlation Between Rotation And Emission Of Pulsars

Both normal pulsars and millisecond pulsars show timing noise.The correlation between variation of rotation and change of pulse shape have been detected in 10 pulsars.The purpose of this paper is to search more samples which have such correlation between the rotation and emission,this work may help us understand the physics of pulsar magnetosphere and internal of pulsar.Combining the timing data from Nanshan 25 m radio telescope and Parkes 64 m dish,we analyzed the rotations of PSR J1539-5626,J1832-0827,J1847-0402 and J1733-3716 using pulsar timing method.Strong timing noise dominates the timing residuals of the four pulsars,the slope for the power spectrum of timing noise is-6,-6,-4.5 and-6.5,the intensity of the power spectrum is 1.77×10-17yr 3,4.43×10-18 yr3,2.09×10-18 yr3 and 1.18×10-18 yr3,respectively.These pulsars show fluctuations of spin-down rates,the variation of the first derivative of the rotation frequency is 0.61(3)×10-15 s-2,0.54(5)×10-16 s-2,0.11(2)×10-15 s-2 and 1.2(3)×10-16 s-2.With the data from Parkes 64 m radio telescope,we estimate the width(full width at half maximum,FWHM of integrated pulse profiles.These pulsars show obvious variations of pulse profiles,the variation of pulse width is 0.0028(6),0.00059(3),0.00011(4)and 0.014(2)phase.In order to investigate the change of pulse profile of PSR J1733-3716,we downloaded and processed 11 single-pulse data with center frequency of 1382MHz.There were two different states which are weak state and strong state,the strong state consist of three different modes in which normal mode,left mode and right mode.The weak state was dominated PSR J1733-3716 that accounting for about 63%of the total single-pulse data.In addition,we calculated the correlation coefficient between the rotational parameters and FWHM,it was found that there is no obvious strong association between the spin-down rate and FWHM.