Parkes observations for project P958 semester 2019OCTS_45

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（FRBs）所引发的疑问始终远超其已解答的问题。直至去年，仅有一例被证实会重复爆发的射电暴，被精确定位至遥远矮星系内的明亮射电星云——即年轻超新星遗迹或脉冲星风云。
过去两年间，依托澳大利亚平方千米阵列探路者（ASKAP）开展的巡天观测共探测到31例快速射电暴，其中5例被精确定位至红移值介于0.1至0.5之间的宿主星系。此类射电暴及其宿主星系与此前已知的重复暴特征差异显著，暗示该类暴源群体或存在二分性。然而近期研究发现，其中一例经角分级定位的ASKAP探测FRB会重复爆发。
本研究拟针对该类FRB群体开展重复暴搜寻与特性研究。我们将依托完备的样本库，对已精确定位的射电暴开展高密度监测，本次监测的能流阈值较此前探测阈值低60倍以上，以量化统计可重复爆发的射电暴占比。对于确认存在重复爆发的暴源，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辐射机制。