Parkes observations for project P456 semester 2008APRS_01

The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision, with three pulsars having rms residuals of less than or about 100 ns and more than half less than 1 microsecond. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project.

帕克斯脉冲星计时阵列（Parkes Pulsar Timing Array, PPTA）项目设有三大核心目标：（a）探测来自各类天文源的引力波；（b）建立标准化脉冲星时标系统；（c）深化对太阳系动力学机制的认知。该项目同时涵盖诸多次级目标，部分涉及天体物理研究，部分聚焦于仪器研发与技术创新。要达成这些极具雄心的核心目标，需在数年周期内，以至少两种、优选三种宽间隔观测频率，对至少20颗毫秒脉冲星（Millisecond Pulsars, MSPs）开展高频次观测。我们计划以2至3周的间隔持续观测PPTA样本阵列，同时使用10/50厘米口径接收机与多波束接收机。数据记录采用数字滤波器组（PDFB3、PDFB4）与基带系统（CPSR2、APSR）。依托新型仪器设备与高效流水线处理系统的研发进展，我们已实现全球领先的脉冲星计时精度：其中三颗脉冲星的残差均方根值小于或约等于100纳秒，超过半数的脉冲星残差均方根值小于1微秒。我们正与欧洲脉冲星计时阵列（EPTA）、北美脉冲星计时阵列（NANOGrav）团队展开合作，以获取更高频次的观测数据与更大规模的脉冲星样本。由于项目需具备高灵敏度与宽带宽特性，射频干扰（Radio Frequency Interference, RFI）抑制是该项目的重要组成部分。