脉冲星巡天模拟

发布时间：2018-04-27 21:40

本文选题：脉冲星 + FAST　；参考：《西华师范大学》2016年硕士论文

【摘要】：射电脉冲星巡天是探测获取更多脉冲星的重要途径。本文首先介绍了影响射电脉冲星巡天效率的众多因素,可将这些因素分成两类,一是射电望远镜仪器本身因素,包括:望远镜口径大小、观测频率、观测带宽、积分时间、采样时间、数字化损失及系统温度;二是脉冲星自身特性,包括:色散量、周期和有效脉冲宽度。此外,总结了现有脉冲星巡天项目,利用Parkes多波束脉冲星及两次扩充巡天(Swinburne中纬度脉冲星巡天和Parkes高纬度脉冲星巡天)结果,采用包含时间演化的脉冲星分布模拟软件PsrPopPy,模拟得到脉冲星在银河系中分布的样本,并对近邻太阳系1kpc距离内的脉冲星数目进行了估算,获得了近邻脉冲星样本,可为脉冲星高能辐射对探测宇宙线正电子谱影响等研究提供可靠输入量。五百米口径球面射电望远镜(FAST)将在2016年建设完成,并即将进入早期科学阶段。在此阶段计划使用FAST超宽带接收机(覆盖频带约270到1620 MHz之间)进行脉冲星漂移巡天。在此之前有关FAST脉冲星巡天的工作都没有涉及早期科学阶段的研究,并且也还没有于用超宽带接收机做射电脉冲星巡天的最佳算法。为弥补这些空缺,我们给出一套可用于FAST早期科学阶段用超宽带接收机进行的脉冲星漂移巡天后所得数据的分析方法。此外,我们还自行开发了一套脉冲星数据模拟软件,使用此软件可模拟得到使用超宽带接收机做脉冲星漂移巡天后的脉冲星观测数据。并使用脉冲星搜寻软件SIGPROC对模拟所得的数据进行处理,进而估算出了FAST超宽带接收机做脉冲星漂移巡天的灵敏度。结果显示,FAST超宽带接收机一次漂移巡天的灵敏度约为40μJy。在获得FAST超宽带接收机脉冲星漂移巡天灵敏度基础之上,从球状星团中脉冲星产生率出发,结合现有的经验公式,对FAST早期科学的对球状星团中脉冲星漂移巡天探测率进行了估算。结果显示,FAST天区内有4个球状星团能在单次漂移观测后探测到脉冲星。再将漂移观测次数进行非相关叠加后,有10个球状星团能在10次扫描内就可有脉冲星被发现。
[Abstract]:Radio pulsar survey is an important way to detect more pulsars. In this paper, many factors affecting the efficiency of radio pulsar survey are introduced. These factors can be divided into two categories. One is the radio telescope instrument itself, including the telescope aperture size, observation frequency, observation bandwidth, integral time, etc. Sampling time, digital loss and system temperature; second, pulsar's own characteristics, including dispersion, period and effective pulse width. In addition, the existing pulsar survey projects are summarized, using Parkes multi-beam pulsars and two extended surveys Swinburne mid-latitude pulsars and Parkes high-latitude pulsar surveys. The pulsar distribution simulation software PsrPopPyincluding time evolution is used to simulate the pulsar distribution in the Milky way, and the number of pulsars within the 1kpc distance of the nearest solar system is estimated, and the nearest neighbor pulsar sample is obtained. It can provide reliable input for the study of the influence of high energy radiation of pulsars on the detection of positron spectra of cosmic rays. FAST, a 500-meter spherical radio telescope, will be completed in 2016 and will soon enter the early scientific phase. At this stage, FAST UWB receivers (covering a range of about 270 to 1620 MHz) are planned for pulsar drift surveys. Previous work on the FAST pulsar survey did not involve the early scientific stage, and there was no optimal algorithm for using UWB receivers to perform radio pulsar surveys. In order to fill these gaps, we present a method for analyzing the data obtained from the pulsar drift survey in the early scientific stage of FAST using ultra-wideband (UWB) receivers. In addition, we have developed a set of pulsar data simulation software, which can be used to simulate the pulsar observation data after pulsar drift survey using UWB receiver. The simulation data are processed by the pulsar search software SIGPROC, and the sensitivity of the FAST ultra-wideband receiver for pulsar drift survey is estimated. The results show that the sensitivity of one drift survey of fast UWB receiver is about 40 渭 JY. On the basis of obtaining the sensitivity of pulsar drift survey in FAST UWB receiver, based on the pulsar generation rate in globular clusters, combined with the existing empirical formulas, The early scientific detection rate of pulsar drift survey in globular cluster was estimated by FAST. The results show that four globular clusters can detect pulsars in the fast region after a single drift observation. 10 globular clusters can be detected within 10 scans.
【学位授予单位】：西华师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P145.6;P111.44

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