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Using observational data obtained with the Five-hundred-meter Aperture Spherical radio Telescope, we succeeded in identifying subcomponents of different pulse profile components of PSR B1822−09 by the phase-to-phase cross correlations between intensity sequences of single pulses. The determined number of the subcomponents and edges of the subcomponents are consistent with the results of Gaussian fitting on the mean pulse profiles of PSR B1822−09. According to the results, the main pulse (MP) in both the radio burst mode (B mode) and the radio-quiet mode (Q mode), the precursor (PC), and the interpulse (IP) of PSR B1822−09 are all composed of three subcomponents. The correlation coefficients between intensity sequences at different pulse phases reveal a positive correlation between the subcomponent C8 of the MP and C3 of the IP in the Q mode, and a positive correlation between C5 of the PC and C2 of the IP during the switching process from the B mode to the Q mode. These complex correlations present a challenge for the existing scenarios that describe relations between different pulse profile components. We proposed a hypothesis that different subcomponents correspond to different subpatches on the pulsar surface, and emissions from a subpatch reveal responses of the subpatch to some variations like the voltage in the magnetosphere. Therefore, correlations between different subcomponents depend on the responses of the subpatches to the variations. [ABSTRACT FROM AUTHOR]

We reported the first glitch of PSR B2021+51 detected with the Shanghai Tian Ma Radio Telescope that occurred around MJD 58289.1 (2018 June 20). The spin frequency and its derivative suffered a jump of about 7.04 × 10−10 Hz and 2.6 × 10−18 s−2, respectively. The pulse width at the 10% intensity level (W10) of the mean pulse profile significantly decreased right before the glitch and then increased after the glitch, accompanied by an enhancement in the trailing peak of the normalized profile. The mean pulse profiles were decomposed into three Gaussian components, i.e., C1, C2, and C3 from left to right by peak phase. The width of C3 (w3) had an apparent maximum right before the glitch and its weighted mean value became slightly smaller than the pre-glitch value after the glitch, while the weighted mean values of both w1 and w2 had no apparent change. The significant decrease of the mean pulse width right before the glitch is mainly due to the movement of C3 toward C1 and C2, while the increase of the mean pulse width after the glitch results from the movement of C2 toward C3. Changes in the widths of mean pulse profiles and in the widths and phase separations of Gaussian components associated with the glitch convinced us of a connection between the changes in characteristics of the pulsar emission zone and the glitch activity. We discuss a possible interpretation invoking the movements of flux tubes in the emission zone. [ABSTRACT FROM AUTHOR]

Chen et al. (2011) found that the durations (timescales) of the normal and abnormal modes of PSR B0329+54 follow a gamma distribution, and constrained the parameters of the distribution function. In this paper, we perform a further analysis on the relationship between the timescales of the two modes. The ratio between the durations of a normal mode and the succeeding abnormal mode is calculated for 54 such pairs. It is found that the cumulative distribution function (CDF) of the ratio is consistent with the CDF obtained by assuming random mode switching, suggesting that the two modes work independently. [ABSTRACT FROM PUBLISHER]