Parkes observations for project P958 semester 2020APRS_07

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，仅有一例被证实会重复爆发的射电暴，被精确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或脉冲星风云星云）。
近三年来，依托澳大利亚平方千米阵探路者（Australian Square Kilometre Array Pathfinder, ASKAP）开展的巡天观测已探测到35次射电暴，其中8次被定位至红移范围0.1至0.5的宿主星系。这些射电暴及其宿主星系与此前发现的重复暴特征差异显著，暗示该类天体的爆发群体或存在二分性。不过，近期研究发现，一例经角分级定位的ASKAP探测FRB同样存在重复爆发现象。
本研究拟对该FRB群体开展重复爆发特征的搜寻与研究工作。我们将通过完备的样本采集与针对精确定位射电暴的高密度监测计划，将通量探测极限压低至此前探测水平的1/60以下，以表征发生重复爆发的射电暴占比。对于存在重复爆发的射电暴，我们将利用独特的宽带宽观测数据，检验当前主流的射电暴辐射模型。