Parkes observations for project P958 semester 2019OCTS_48

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. Over 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. 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）至今引发的疑问仍远多于其所能解答的谜团。直至去年，已知仅存在一例会重复爆发的快速射电暴，该暴源被定位至遥远矮星系内的明亮射电星云（年轻超新星遗迹或脉冲星风云星云）。过去两年间，依托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例快速射电暴，其中5例被精确定位至红移值介于0.1至0.5之间的宿主星系。此类暴源及其宿主星系与此前的重复暴源特征迥异，暗示快速射电暴群体或存在二分性。不过近期研究发现，经ASKAP完成角距离定位的一例FRB同样存在重复爆发现象。本文拟针对该FRB群体开展重复爆发特征的搜寻与研究：我们将依托完整的样本集，对已精确定位的暴源实施高密度监测计划，其能流极限较此前的探测阈值低60倍以上，以此量化统计可重复爆发暴源的占比；针对存在重复爆发的暴源，我们将借助独具优势的宽波段观测数据，检验当前主流的暴源辐射模型。