Parkes observations for project P958 semester 2019OCTS_58

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）带来的疑问远多于其已解答的问题。直至去年，仅有一种暴——也是目前已知唯一会重复爆发的暴——被定位至遥远矮星系中的明亮射电星云（要么为年轻超新星遗迹，要么为脉冲星风云星云）。
过去两年间，借助澳大利亚平方千米阵探路者（Australian Square Kilometre Array Pathfinder, ASKAP）开展的巡天探测已发现31次快速射电暴，其中5次被定位至红移值介于0.1至0.5之间的宿主星系。这些暴及其宿主星系与此前发现的重复暴截然不同，这暗示快速射电暴群体或许存在二分性。然而近期研究发现，其中一颗经角分级定位的ASKAP探测到的FRB会重复爆发。
本研究计划针对该FRB群体开展重复爆发特征的搜寻与研究。我们将采用覆盖全面的样本，并对定位精准的暴体开展密集监测计划，将通量探测极限设定为此前探测阈值的1/60以下，以此量化发生重复爆发的暴体所占比例。对于存在重复爆发特征的暴体，我们将借助独具特色的宽带宽观测数据，检验当前主流的射电暴辐射机制模型。