Parkes observations for project P1068 semester 2020APRS_31

In the fast-moving world of Fast Radio Bursts (FRBs), the key question of what fraction (as high as 100%?) of FRBs emit repeat bursts remains unanswered. Of order 10 repeating FRBs are now known, and their spectro-temporal properties hint at differences with apparently non-repeating bursts - but poor statistics preclude a definitive diagnosis. FRB 180301 is a promising source for further study for multiple reasons: it is the first repeating FRB seen by the FAST telescope, and has the second-highest rotation measure ever seen for a FRB (after the original repeater, FRB121102). We request Parkes observations with the UWL to characterise the broadband emission properties of this FRB, with the following key goals: to constrain the repetition rate, identify any variation of pulse characteristics over time, and provide insight into the emission mechanisms. In its initial detection, FRB 180301 was poorly fit by regular Faraday rotation models, and showed significant circular polarization, which may indicate the progenitor is embedded in an extreme magneto-ionic environment with complex field structure that has not been seen before. These observations will generate a large data volume. We will use the Medusa backend in parallel with the Breakthrough Listen data recorder (BL), and will transfer data to BL immediately after observations.These data will be used by P. Kumar to prototype a FRB pipeline for the UWL, that will be made broadly available for similar studies.在快速射电暴（Fast Radio Bursts, FRBs）研究领域飞速发展的当下，一个核心科学问题仍悬而未决：究竟有多大比例（最高可达100%？）的快速射电暴会产生重复爆发脉冲。目前已知约10例重复爆发的快速射电暴，其谱时特性显示出与非重复暴的差异，但受限于统计样本不足，无法给出确定性结论。FRB 180301是极具后续研究价值的目标，原因有二：其一，它是500米口径球面射电望远镜（Five-hundred-meter Aperture Spherical Telescope, FAST）发现的首个重复暴快速射电暴；其二，其旋转量度（Rotation Measure, RM）位列所有已知快速射电暴第二位，仅次于首个被发现的重复暴FRB 121102。我们申请使用搭载UWL设备的帕克斯射电望远镜（Parkes Telescope）开展观测，以刻画该快速射电暴的宽频辐射特性，核心观测目标包括：限定重复爆发率、识别脉冲特性随时间的演化特征，以及为辐射机制研究提供关键认知。在首次探测中，常规法拉第旋转模型无法较好拟合FRB 180301的观测数据，且该暴呈现出显著的圆偏振现象，这暗示其前身天体嵌入在此前未被观测到的、具有复杂磁场结构的极端磁离子环境中。本次观测将产生海量数据，我们将并行使用美杜莎后端（Medusa backend）与突破聆听（Breakthrough Listen）数据记录仪（BL），并在观测结束后立即将数据传输至BL。P. Kumar将利用这批数据为UWL搭建快速射电暴数据处理流水线原型，该流水线后续将面向同类研究广泛开放共享。