Parkes observations for project P456 semester 2016OCTS

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. The PPTA is the oldest of three international pulsar timing groups. We have the smallest telescope and the smallest group, but the best measurements and the best results. Our bound on the strength of the incoherent gravitational wave background is the only bound which significantly constrains theoretical models. We have maintained our leading position because: we have the southern sky; we have a small but well-focussed group; we have the best-calibrated receivers; and we have been able to observe with an almost regular cadence of 15 to 20 days at three different wavelengths. With this proposal we aim to maintain our pre-eminent position in the field.\r\n\r\nUnlike most observing proposals, this is a continuing proposal for which the observations will continue to improve bounds on gravitational waves until they are finally detected. Continued Parkes observations will remain valuable until the first stage of the SKA is able to offer the same sensitivity as Parkes and the same observing time. Even after the gravitational wave background is detected we will want to continue observations in support of the nascent field of gravitational wave astronomy!

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）探测天体源产生的引力波；（b）建立脉冲星时标系统；（c）深化对太阳系动力学的认知。帕克斯脉冲星计时阵列是三大国际脉冲星计时研究组中历史最悠久的一个。我们虽拥有规模最小的望远镜与研究团队，却取得了最优的测量数据与研究成果。我们针对非相干引力波背景强度给出的约束，是目前唯一能够有效限制相关理论模型的约束条件。我们能够始终保持领先地位的原因在于：坐拥南天球观测天区优势；拥有一支精干且目标聚焦的研究团队；配备了经过最精准校准的接收机；并且能够以15至20天的近乎固定周期在三个不同观测波段开展观测。本次提案旨在巩固我们在该领域的领先地位。

与多数观测提案不同，本提案属于持续性观测项目，相关观测将持续优化引力波探测的约束精度，直至最终成功探测到引力波。帕克斯望远镜的持续观测仍将具备重要科研价值，直至平方千米阵（Square Kilometre Array, SKA）的第一阶段能够提供与帕克斯望远镜相当的灵敏度与观测时长。即便在引力波背景被成功探测之后，我们仍将继续开展观测，以支持这一新兴的引力波天文学研究领域！