Parkes observations for project P282 semester 2007OCTS

From 1989 to 2005, we have discovered a total of 23 millisecond pulsars in 47 Tucanae and obtained coherent timing solutions for 19 of those. This dataset has already allowed studies of stellar evolution and cluster dynamics and the first detection of the interstellar medium in a globular cluster. The remaining scientific objectives of this project can now be accomplished with less intensive, long-term timing: we want to keep track of the rotational phase of these pulsars and increase the number and precision of measured proper motions. The full analysis of all the previous data is still ongoing: we have recently found a new pulsar (47TucZ), confirmed and determined the orbit of a previously know object (47TucX), and determined the timing solutions of three others (the binary pulsar with the shortest orbital period, 47TucR, another eclipsing binary pulsar, 47TucW, and a newly dicovered binary, 47TucY). This has allowed the identification of these three pulsars in X-rays using Chandra and the identification of the companion of 47TucY in optical HST data.

1989年至2005年间，我们在杜鹃座47（47 Tucanae）中共发现23颗毫秒脉冲星（millisecond pulsars），并为其中19颗获得了相干计时解（coherent timing solutions）。本数据集已被用于恒星演化与星团动力学研究，以及首次在球状星团中探测到星际介质。本项目剩余的科学目标如今可通过无需高强度观测投入的长期计时工作完成：我们将持续追踪这些脉冲星的自转相位，并提升自行测量的数量与精度。所有历史数据的全面分析仍在进行中：我们近期新发现一颗脉冲星47TucZ，对此前已知天体47TucX的轨道完成了确认与测定，还确定了另外三颗脉冲星的计时解——分别是拥有最短轨道周期的双星脉冲星47TucR、另一颗食双星脉冲星47TucW，以及新发现的双星脉冲星47TucY。这一成果使得我们能够借助钱德拉X射线天文台（Chandra）识别出这三颗脉冲星的X射线辐射，并通过哈勃空间望远镜（HST）的光学观测数据确认了47TucY的伴星。