利用FAST开展脉冲星单脉冲观测研究

Single-pulse properties are very important for understanding the emission process and the magnetosphere activity of pulsars. However, single-pulse observations are often limited by the low sensitivity of radio telescopes. Based on the ultra-high sensitivity of FAST, this project proposes to make single-pulse studies for pulsars with FAST. This project mainly includes the following three aspects: (1) search for pulsars showing giant pulse, pulse nulling, subpulse drifting or mode changing in the newly discovered pulsars in the drift-scan pulsar survey of FAST, then study their single-pulse properties by long duration single-pulse observations (2 hours for each pulsar), and combine them with the already known pulsars that have those properties to establish a pulsar catalogue for single-pulse studies; (2) carry out high time resolution studies for giant pulses and measure their intrinsic width, intensity and polarization properties to understand the nature of giant pulses; (3) study the interaction among nulling, subpulse drifting and mode changing, and then theoretically explore the physical mechanism for the switching of the magnetosphere between different modes. We believe that this project will certainly promote the level of single-pulse studies of pulsars in China.

脉冲星的单脉冲辐射特性对于揭示脉冲星的辐射过程及磁层活动具有十分重要的意义，而单脉冲观测往往会受到射电望远镜观测灵敏度的限制。依托于FAST超高的灵敏度，本项目提出利用FAST开展脉冲星的单脉冲观测研究，主要研究内容包括以下三个方面：(1) 在漂移扫描巡天的结果中搜寻具有巨脉冲、脉冲消零、子脉冲漂移或模式变换的脉冲星，然后通过长时间的单脉冲观测(每颗源2小时)研究这些脉冲星的单脉冲辐射性质，结合已知具有这些辐射特性的脉冲星，建立这类脉冲星的数据库；(2) 开展巨脉冲的高时间分辨率研究，测量巨脉冲本征的宽度、强度和偏振等特性，认识巨脉冲的本质；(3) 研究脉冲消零、子脉冲漂移和模式变换之间的相互关系，从理论上探讨脉冲星磁层在不同状态之间转换的物理机制。我们相信通过本项目的研究，势必会对我国的脉冲星单脉冲研究水平产生一定的推动作用。

自从脉冲星发现以来，人们对脉冲星的辐射现象有了非常深入的了解。然而，时至今日，脉冲星的射电辐射机制仍是未解之谜。通过使用大型射电望远镜对脉冲星开展单脉冲观测研究，对于揭示脉冲星的辐射过程及磁层活动具有十分重要的意义。本项目使用FAST射电望远镜，并结合其他国内外大型射电望远镜，对一批脉冲星开展了巨脉冲、巨微脉冲、脉冲消零、子脉冲漂移、模式变换等方面的研究。研究发现了新的脉冲星辐射现象，对相关辐射模型提出了新的限制。经过三年的研究，在此项目经费支持下，项目组成员共发表论文11篇，其中SCI论文10篇，第二标注SCI论文5篇，第三标注SCI论文2篇。通过本项目的执行，培养研究生4名。