Parkes observations for project P958 semester 2020APRS_05

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所解答的问题。直至去年，仅有一种暴——也是目前已知唯一会重复爆发的快速射电暴——被定位到遥远矮星系中的一颗明亮射电星云（年轻超新星遗迹或脉冲星风云星云）。
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次被定位到红移值介于0.1至0.5之间的宿主星系。这些暴及其宿主星系与此前已知的重复暴存在显著差异，这暗示快速射电暴群体可能存在两类截然不同的亚型。但近期研究发现，其中一例经角分精度定位的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开展重复爆发特征的搜寻与研究。我们将依托完整的样本库，对定位精度较高的暴源实施密集监测计划，设定的能流极限较此前的探测阈值低60余倍，以此量化分析存在重复爆发现象的快速射电暴占比。针对存在重复爆发的暴源，我们将利用独有的宽带宽观测数据，对当前主流的快速射电暴辐射模型开展验证。