In this paper,the emissions from two pulsars,PSRs J1611-0114 and J1617+1123,were investigated using th Five-hundred-meter Aperture Spherical radio Telescope operating at a central frequency of 1250 MHz.Th average puls...In this paper,the emissions from two pulsars,PSRs J1611-0114 and J1617+1123,were investigated using th Five-hundred-meter Aperture Spherical radio Telescope operating at a central frequency of 1250 MHz.Th average pulse profile of PSR J1611-0114 shows two components,the first of which is relatively weak in intensity The two-dimensional pulse stack exhibits an obvious nulling phenomenon,with an estimated nulling fraction o40.1%±5.4%.The durations of the nulls and bursts are consistent with power-law distributions,and no periodi nulling phenomenon is found.The results from PSR J1617+1123 demonstrate that the average pulse profile i composed of four components.The peak intensity of the fourth component varies significantly,causing an unstabl integrated profile.In addition,the modulation characteristics of J1611-0114 and J1617+1123 were studied by analyzing the modulation index,longitude resolved fluctuation spectrum and two-dimensional fluctuation spectrum using the software PSRSALSA.It was found that the two pulsars exhibit intensity modulation.In particular,J1611-0114 displays even-odd modulation,with the modulation period of approximately two pulses.The modulation period of J1617+1123 is relatively broad.There is an obvious subpulse drift phenomenon,and the value of P_(2)i~0.125c/P_(0),corresponding to 12 pulse longitude bins,and the drift rate(P_(2)/P_(3))is about 0.29.展开更多
Determining accurate pulsar timing model parameters is essential for establishing TT(PT),a realization of Terrestrial Time(TT)based on a pulsar timescale(PT).This study discusses the impact of different data spans on ...Determining accurate pulsar timing model parameters is essential for establishing TT(PT),a realization of Terrestrial Time(TT)based on a pulsar timescale(PT).This study discusses the impact of different data spans on the accuracy of pulsar timing model parameters when determining pulsar timing model parameters.Using observations of PSR J0437-4715,J1909-3744,J1713+0747,and J1744-1134 from the second data release of the International Pulsar Timing Array(IPTA II,Version A),we compare the accuracy of the timing model parameters determined by these observations with different data spans.The results show for PSR J0437-4715,J1713+0747,and J1909-3744,the amplitude fluctuations of rotational frequency remain within 10^(−15),10^(−14),and 10^(−14) Hz,respectively,when the data spans for determining pulsar timing model parameters exceed 13,14,and 6 yr.Additionally,the one-year accuracy of TT(PT)is crucial for its application in timekeeping.By comparing the frequency deviations of TT(PT)relative to TT(BIPM)under both ideal(k_(r))and actual(k_(p))conditions across different data spans,we find that when the data span reaches the duration above,the accuracy of TT(PT)surpasses that of TT(TAI)under ideal conditions,slightly inferior under actual conditions.This suggests with improved observational technologies,the accuracy of TT(PT)can be further enhanced.展开更多
基金supported by National Key Research and Development Program of China(2022YFC2205203)the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(No.2022A03013-1)+9 种基金the National Natural Science Foundation of China(NSFC,grant Nos.U1838109 and 12041304)supported by the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(No.2022A03013-1)National Natural Science Foundation of China(NSFC,Grant No.12303053)the 2021 project Xinjiang Uygur autonomous region of China for Tianshan elites,the Youth Innovation Promotion Association of CAS under No.2023069the Tianshan Talent Training Program(No.2023TSYCCX0100)supported by the National SKA Program of China(grant No.2020SKA0120200)the National Natural Science Foundation of China(NSFC,grant Nos.12041303,12273100 and12288102)the National Key R&D Program of China(grant No.2022YFC2205201)the West Light Foundation of the Chinese Academy of Sciences(grant No.WLFC 2021-XBQNXZ-027)the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(grant No.2022A03013-4)。
文摘In this paper,the emissions from two pulsars,PSRs J1611-0114 and J1617+1123,were investigated using th Five-hundred-meter Aperture Spherical radio Telescope operating at a central frequency of 1250 MHz.Th average pulse profile of PSR J1611-0114 shows two components,the first of which is relatively weak in intensity The two-dimensional pulse stack exhibits an obvious nulling phenomenon,with an estimated nulling fraction o40.1%±5.4%.The durations of the nulls and bursts are consistent with power-law distributions,and no periodi nulling phenomenon is found.The results from PSR J1617+1123 demonstrate that the average pulse profile i composed of four components.The peak intensity of the fourth component varies significantly,causing an unstabl integrated profile.In addition,the modulation characteristics of J1611-0114 and J1617+1123 were studied by analyzing the modulation index,longitude resolved fluctuation spectrum and two-dimensional fluctuation spectrum using the software PSRSALSA.It was found that the two pulsars exhibit intensity modulation.In particular,J1611-0114 displays even-odd modulation,with the modulation period of approximately two pulses.The modulation period of J1617+1123 is relatively broad.There is an obvious subpulse drift phenomenon,and the value of P_(2)i~0.125c/P_(0),corresponding to 12 pulse longitude bins,and the drift rate(P_(2)/P_(3))is about 0.29.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(grant No.XDA0350502)the National SKA Program of China(No.2020SKA0120103)the National Natural Science Foundation of China(No.U1831130).
文摘Determining accurate pulsar timing model parameters is essential for establishing TT(PT),a realization of Terrestrial Time(TT)based on a pulsar timescale(PT).This study discusses the impact of different data spans on the accuracy of pulsar timing model parameters when determining pulsar timing model parameters.Using observations of PSR J0437-4715,J1909-3744,J1713+0747,and J1744-1134 from the second data release of the International Pulsar Timing Array(IPTA II,Version A),we compare the accuracy of the timing model parameters determined by these observations with different data spans.The results show for PSR J0437-4715,J1713+0747,and J1909-3744,the amplitude fluctuations of rotational frequency remain within 10^(−15),10^(−14),and 10^(−14) Hz,respectively,when the data spans for determining pulsar timing model parameters exceed 13,14,and 6 yr.Additionally,the one-year accuracy of TT(PT)is crucial for its application in timekeeping.By comparing the frequency deviations of TT(PT)relative to TT(BIPM)under both ideal(k_(r))and actual(k_(p))conditions across different data spans,we find that when the data span reaches the duration above,the accuracy of TT(PT)surpasses that of TT(TAI)under ideal conditions,slightly inferior under actual conditions.This suggests with improved observational technologies,the accuracy of TT(PT)can be further enhanced.
