摘要
快速射电暴于2007年首次在脉冲星巡天的历史数据中被发现,是一种在射电波段观测到的具有色散量的单个强脉冲,其特征为持续时间仅为若干毫秒,峰值流量密度可达到央斯基量级。类似于射电脉冲星的单个脉冲,但其色散显著超过同一视线方向上银河系内星际介质的预期最大值。对截止2018年6月帕克斯望远镜、绿岸望远镜、阿雷西博射电望远镜、UTMOST望远镜和ASKAP望远镜已探测到的52例快速射电暴进行了观测量统计分析,根据模型扣除银河系星际介质导致的色散量后,快速射电暴平均色散量为584.5 pc·cm^(-3),暗示着快速射电暴来自河外。通过最佳拟合估算红移幂律分布谱dN/dF_(obs)=4.14±1.30×F■sky^(-1)·day^(-1)。根据分析结果预计,FAST望远镜使用19波束接收机后,其多科学目标同时巡天在经过一年时间内能发现大约10个快速射电暴,将有效地扩大样本数量,为快速射电暴研究提供重要信息。
Fast Radio Bursts(FRBs)were first discovered in pulsar search data in 2007,they are intense radio flashes and characterized by millisecond durations and Jansky-level flux densities.FRBs are single pulses which are similar to pulses from radio pulsars.They have unexpectedly high dispersion measures(DM)than those from the modeled DM up limits from the entire Milky Way Interstellar Medium(ISM)in the same line of sight.They can be a powerful probe for studying the ionized intergalactic medium and the spatial distribution of free electrons.We carried out a statistical analysis on the 52 FRBs discovered by the Parkes,GBT,Arecibo,UTMOST and ASKAP until June 2018.After subtracting the DM values which were from the modeled interstellar medium of our Galaxy,their mean dispersion measure is 584.5 pc·cm^-3,supporting the conclustion of their cosmological origin.The Power-law distribution can be described as d N/d F obs=4.14±1.30×Fobs^-1.120 55 sky^-1·day^-1.After the Five-hundred-meter Aperture Spherical radio Telescope(FAST)deploying the L-band19-beam array,the Commensal Radio Astronomy FAST Survey(CRAFTS)will be able to detect about10 FRBs every year.This will effectively expand the sample of FRBs and provide iImportant information on FRB′s research.
作者
余秋雨
刘志杰
王培
Yu Qiuyu;Liu Zhijie;Wang Pei(Key Laboratory of Information and Computing Science in Guizhou Province,Guizhou Normal University,Guiyang 550001,China;National Astronomical Observatories,Chinese Academy of Sciences,Beijing100012,China)
出处
《天文研究与技术》
CSCD
2019年第2期167-177,共11页
Astronomical Research & Technology
基金
国家自然科学基金(U1631132
U1731238
U1831131
11603046)资助
