Parkes observations for project P282 semester 2013APRS

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), and two very good new candidates, confirmed a previously know object (47TucX), and determined the timing solutions of three others (the binary pulsar with the shortest orbital period, 47 Tuc R, another eclipsing binary pulsar, 47TucW, and a newly dicovered binary, 47 Tuc Y). 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. Some of the 47 Tuc pulsars are now becoming detectable at gamma-rays with Fermi, but we need to keep updated radio ephemerides.

1989年至2005年间，我们在杜鹃座47（47 Tucanae）中总计发现23颗毫秒脉冲星（millisecond pulsar），并为其中19颗获得了相干计时解。本数据集已支撑恒星演化、星团动力学相关研究，并首次在球状星团（globular cluster）中探测到星际介质（interstellar medium）。本项目剩余的科学目标可通过低强度的长期计时观测完成：我们将追踪这些脉冲星的自转相位，并增加自行（proper motion）测量的样本量、提升测量精度。目前所有过往观测数据的完整分析工作仍在进行中：我们近期新发现1颗脉冲星（47TucZ）与2颗优质候选体，证实了1颗此前已知的天体（47TucX），并确定了另外3颗天体的计时解：包括轨道周期最短的双星脉冲星47 Tuc R、另一颗食双星脉冲星47TucW，以及新发现的双星脉冲星47 Tuc Y。这一成果使得我们能够利用钱德拉（Chandra）X射线天文台在X射线波段完成这三颗脉冲星的证认，并通过哈勃空间望远镜（HST）的光学观测数据完成了47TucY的伴星证认。目前部分杜鹃座47脉冲星已可通过费米（Fermi）伽马射线望远镜被探测到，但我们仍需持续更新其射电星历（radio ephemerides）。