Parkes observations for project P958 semester 2020APRS_35

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）所引发的疑问远多于其已解答的问题。直至去年，仅有一种暴——即目前已知的唯一重复暴——被定位到遥远矮星系中的明亮射电星云（要么是年轻超新星遗迹，要么是脉冲星风云星云）内。
过去三年间，借助澳大利亚平方千米阵列探路者（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。这些暴及其宿主星系与该重复暴的特征差异显著，这暗示快速射电暴的群体或存在二分性。然而，近期研究发现其中一台经角分定位的ASKAP探测快速射电暴存在重复爆发现象。
在此，我们提出针对该快速射电暴群体开展重复爆发的搜寻与研究工作。我们将采用流量密度极限较此前探测阈值低60倍以上的观测方案，结合完备的样本集与针对精确定位暴的高密度监测计划，以量化存在重复爆发的快速射电暴所占比例。对于存在重复爆发的暴，我们将借助独具特色的宽带宽观测数据，检验当前主流的快速射电暴辐射模型。