毫秒脉冲星计时观测的研究进展

Recent Progress in Timing Observations and Investigations of Millisecond Pulsars

对毫秒脉冲星时间测量的理论、方法和技术研究的进展进行了阐述。根据近年来取得的观测研究结果，毫秒脉冲星计时测量误差～2×10－7秒，毫秒脉冲星自转周期稳定性足以和现代原子钟相媲美：其相对频率不稳定度达到1×10－14（1年≤γ≤5．2年），并可望更高。近年来，脉冲星计时观测系统的接收灵敏度获得很大改进，计时观测的数据采集、处理技术、脉冲到达时间分析模型研究等都有长足发展。通过综合脉冲星时间算法得到的脉冲星时间尺度将比现代原子时具有更高的长期稳定度。叙述了脉冲星的物理特性及有关计时观测系统的技术成果，如观测频率和带宽的选择，消色散和接收系统灵敏度等问题。最后对毫秒脉冲星时间测量的误差源进行了讨论，并对脉冲星时间尺度的应用前景做了展望。

Recent progress in both theoratical and technical investigations of timing observations and analyses for millisecond pulsars Is introduced in this paper．The new results show that the precision for the timing observations of millisecond pulsars is of the order of 10-7 secod， and that the stability of rotation of millisecond pulsars mny rival that of atomic clocks： The relative frequency instability for the averaging times of over one year is of order 10-14． Today the sensitivity for the pulsar timing system has reached a high level． The techniques of data acquisition and the model analysis for the pulse arrival time of millisecond pulsars have been updated． An ensemble pulsar time can be deduced through a long-term stability algorithm， and it is shown that applying this algorithm to pulsar timing data， the pulsar time could become more stable than the present atomic time， for averaging times of a few years．In this paper， the physical characteristics of pulsars and some key technical development in pulsar timing observation system,such as the selection of observational frequency and bandwidth， the differential dispersion removal， the improvement of sensitivity of reseiver system， and the sources of error in timing measurements are also discussed． At last， the prospets for application of pulsar time in the future is presented in the paper．