Parkes observations for project P958 semester 2019OCTS_70

Fast radio bursts (FRBs) continue to raise more questions than they answer. Until last year, only one burst – the only one known to repeat - had been localized to a bright radio nebula (either a young supernova remnant or pulsar wind nebulae) in a distant dwarf galaxy. \r\nOver the last two year searches with the Australian Square Kilometre Array Pathfinder (ASKAP) have detected 31 bursts, five of which have been localised to host galaxies at redshifts ranging from 0.1 to 0.5. These bursts and their hosts are very unlike the repeater, suggesting there may be a dichotomy in the population. However one of the arcminute-localised ASKAP FRBs has recently been found to repeat.\r\n Here we propose to search and study repetitions in this FRB population. Our comprehensive sample and a dense monitoring campaign of well localised bursts, at a fluence limit more than 60 times lower than that of their detections to characterise the fraction of bursts that repeat. For bursts that repeat the unique wide bandwidth observations will be used to test leading models of burst emission.

快速射电暴（Fast Radio Bursts，FRBs）引发的问题远多于其解答。截至去年，仅有一个暴——已知唯一的重复暴——被定位到遥远矮星系中的明亮射电星云（可能为年轻超新星遗迹（young supernova remnant）或脉冲星风云（pulsar wind nebulae））。
过去两年间，利用澳大利亚平方公里阵列探路者（Australian Square Kilometre Array Pathfinder，ASKAP）开展的搜索已探测到31个暴，其中5个被定位到红移（redshifts）范围为0.1至0.5的宿主星系。这些暴及其宿主与重复暴存在显著差异，暗示该种群可能存在二分性（dichotomy）。然而，其中一个经角分精度定位的（arcminute-localised）ASKAP FRB最近被发现存在重复现象。
本文提出对该FRB种群的重复现象开展搜索与研究。我们将借助全面样本及针对精确定位暴的密集监测计划（其流量极限（fluence limit）比探测阈值低60余倍），表征重复暴在种群中的比例。对于重复暴，将通过独特的宽波段观测检验主流的暴发射模型（burst emission models）。