Parkes observations for project P958 semester 2019OCTS_79

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）始终是未解之谜多于已知答案。直至去年，仅有一例暴——也是已知唯一的重复暴——被定位到遥远矮星系中的明亮射电星云（可能是年轻超新星遗迹或脉冲星风云）。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例暴，其中5例被定位到红移（redshifts）介于0.1至0.5之间的宿主星系。这些暴及其宿主星系与重复暴存在显著差异，表明该种群可能存在二分性（dichotomy）。然而，近期发现其中一例经ASKAP以角分精度定位的（arcminute-localised）FRB存在重复现象。在此，我们提出对FRB种群中的重复现象开展搜索与研究。我们将利用全面样本及对精确定位暴的密集监测计划（dense monitoring campaign）——其流量密度极限（fluence limit）比探测时低60余倍——来表征重复暴的比例。对于重复暴，将通过独特的宽带观测（wide bandwidth observations）测试主流的暴发射（burst emission）模型。