Parkes observations for project P866 semester 2014OCTS

Studies of the 23 MSPs in the globular cluster (GC) 47 Tucanae (47 Tuc) have provided a wealth of interesting science. Timing of these MSPs (all with periods between 2 and 8 ms) has enabled us to probe the environment and dynamics of the cluster in impressive detail and has allowed us to put constraints on the masses of several of the pulsars. However, previous studies of the cluster were limited by the hardware used. The AFB provided 1-bit digitisation and relatively coarse 88 us sampling. Through the use of the CASPSR backend, we will observe 47 Tuc and its 23 MSPs with unprecedented time resolution. For timing we will achieve almost two orders of magnitude better time resolution, allowing us to resolve out features in the profiles of several cluster pulsars, greatly improving their timing accuracy. For search purposes the CASPSR backend will provide a coherently dedispersed filterbank file at the cluster's dispersion measure. We will search this data using state-of-the-art GPU acceleration searching codes to hunt for compact binary systems. In tandem with timing and searching, we will perform real-time transient searching to hunt for fast radio bursts (FRBs). Through shadowing with the Molonglo telescope, we will be able to provide the best localisation, spectral index measurement and repetition limits for any detected FRB. This will provide us with much needed information for multi-wavelength follow-up and will give new insight into the origins of these mysterious events.

针对球状星团（globular cluster, GC）杜鹃座47（47 Tucanae，简称47 Tuc）中的23颗毫秒脉冲星（millisecond pulsar, MSP）所开展的研究，已催生大量极具科学价值的成果。对这些脉冲周期介于2至8毫秒的毫秒脉冲星进行计时观测，使我们得以极为细致地探究该星团的环境与动力学特性，并对多颗脉冲星的质量给出约束。然而，此前针对该星团的研究受限于所使用的观测硬件：此前搭载的AFB设备仅支持1比特数字化，且采样精度较为粗糙，仅为88微秒。借助CASPSR后端设备，我们将以前所未有的时间分辨率对杜鹃座47及其23颗毫秒脉冲星开展观测。在计时观测方面，我们的时间分辨率将提升近两个数量级，能够解析出该星团内多颗脉冲星的轮廓细节，大幅提升其计时精度。在搜索观测场景下，CASPSR后端将生成该星团色散量（dispersion measure）下的相干去色散滤波组文件。我们将采用当前最先进的GPU加速搜索程序处理该数据，以搜寻致密双星系统。在开展计时与搜索观测的同时，我们还将进行实时暂现源搜索，以搜寻快速射电暴（fast radio bursts, FRBs）。通过与莫隆洛望远镜（Molonglo Telescope）进行协同观测，我们将能够为任何探测到的快速射电暴提供迄今最优的定位精度、谱指数测量结果以及重复爆发限制条件。这将为多波段后续观测提供亟需的关键信息，并为揭开这类神秘事件的起源提供全新视角。