光子TOA与自转频率误差对Crab脉冲星脉冲TOA估计的影响

Influence of photon TOA and rotation frequency error on pulse TOA estimation of Crab pulsar

关键词:  Crab脉冲星  脉冲TOA  仿真观测  随机误差  自转频率误差  测量误差

Key words:  Crab pulsar  Pulse TOA  Simulated observation  Random error  Error of rotation frequency  Measurement error

摘要:

为量化分析Crab脉冲星X射线波段光子到达时间（TOA）测量误差和自转频率误差对脉冲TOA估计的影响，仿真生成了13 200组带有不同光子TOA测量误差的光子TOA数据。采用含有不同大小自转频率误差的Crab脉冲星星历，通过历元折叠建立积分脉冲轮廓，与标准脉冲轮廓作互相关运算获得各组仿真观测的脉冲TOA测量误差，进一步计算出各误差参数组的仿真观测脉冲TOA测量误差均方根（RMS）。仿真结果表明，为使Crab脉冲星脉冲TOA短期测量精度达到30 ~300 μs量级的要求，有效面积为6 000 cm2和30 cm2的探测器脉冲星自转频率误差均应小于3×10-6 Hz，30 cm2的探测器光子TOA的偶然误差同时应控制在500 μs以内。

Abstract:

In order to quantify the influence of photon time of arrival (TOA) measurement error and rotation frequency error on pulse TOA estimation of Crab pulsar in X-ray band, 13 200 sets of photon TOA data with different photon TOA measurement errors are simulated and generated. The Crab pulsar ephemeris with different rotation frequency errors is used to establish integrated pulse profiles through epoch folding, and the pulse TOA measurement error of each group of simulated observations is obtained by cross-correlation operation with the standard pulse profile, and the root mean square (RMS) measurement error of the simulated observation pulse TOA of each error parameter group is further calculated. The simulation results show that in order to make the short-term measurement accuracy of Crab pulsar pulse TOA reach the order of 30~300 μs, the error of the pulsar rotation frequency of the detector with 6 000 cm2 effective area and 30 cm2 effective area should also be less than 3×10-6 Hz, and accidental error of photon TOA measurement of the detector with 30 cm2 effective area should be controlled within 500 μs.