Parkes observations for project P958 semester 2019OCTS_23

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 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.\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所能解答的问题。直至去年，仅有一例已知会重复的暴被定位至遥远矮星系中的明亮射电星云（年轻超新星遗迹或脉冲星风云星云）。
过去两年间，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31例暴，其中5例被定位至红移范围0.1至0.5的宿主星系。这些暴及其宿主星系与此前的重复暴特征差异显著，暗示该暴群或存在二分性。不过，近期有一项针对角分级定位的ASKAP FRB的研究发现其存在重复现象。
本研究拟对该FRB群中的重复现象开展搜寻与研究。我们将构建完备的精确定位暴源样本，并开展高密度监测计划，其能流极限较此前的探测阈值低60倍以上，以表征重复暴的占比。对于存在重复的暴源，我们将借助独特的宽带宽观测数据，检验当前主流的暴辐射模型。