Parkes observations for project P958 semester 2020APRS_32

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 three years searches with the Australian Square Kilometre Array Pathfinder (ASKAP) have detected 35 bursts, eight 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）的未解之谜仍远多于已解答的问题。截至去年，仅有一例射电暴——且是唯一已知的重复爆发事件——被定位至遥远矮星系中的明亮射电星云（可能为年轻超新星遗迹（supernova remnant）或脉冲星风云（pulsar wind nebula））。过去三年间，通过澳大利亚平方千米阵探路者（Australian Square Kilometre Array Pathfinder, ASKAP）开展的搜索已探测到35例射电暴，其中8例被定位到红移（redshift）值介于0.1至0.5的宿主星系。这些射电暴及其宿主星系与重复爆发事件存在显著差异，暗示该种群可能具有二分性。然而，近期发现其中一例经ASKAP定位至角分尺度的FRB存在重复爆发现象。在此，我们提出对该FRB种群的重复爆发现象进行搜索与研究。我们将利用全面样本及对精确定位射电暴的密集监测（其流量阈值比探测时所用阈值低60倍以上），来确定重复爆发射电暴的比例。对于重复爆发的射电暴，我们将通过独特的宽带观测数据验证主流的射电暴辐射模型。