Parkes observations for project P958 semester 2020APRS_33

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 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.\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）引发的疑问远多于其已解决的问题。直至去年，仅有一种快速射电暴——也是目前已知唯一会重复爆发的暴——被定位至遥远矮星系内的明亮射电星云（年轻超新星遗迹或脉冲星风云星云）中。
近三年来，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35次快速射电暴，其中8次被定位至红移值介于0.1至0.5之间的宿主星系。这些暴体及其宿主星系与此前已知的重复暴体差异显著，这暗示快速射电暴群体或存在二分性特征。不过近期研究发现，其中一台经角分精度定位的ASKAP探测快速射电暴存在重复爆发现象。
本研究拟针对该快速射电暴群体的重复爆发行为开展搜寻与研究工作。我们将依托完整的样本集，对定位精度较高的暴体开展高密度监测，监测的能流极限较此前的探测阈值低60倍以上，以此量化存在重复爆发行为的暴体占比。针对存在重复爆发的暴体，我们将利用独具特色的宽带宽观测数据，检验当前主流的快速射电暴发射机制模型。