Parkes observations for project P282 semester 2010APRS

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）中共发现23颗毫秒脉冲星（millisecond pulsars），并为其中19颗获取了相干计时解。该数据集已助力开展恒星演化与星团动力学研究，并首次探测到球状星团中的星际介质（interstellar medium）。本项目剩余的科学目标如今可通过低强度的长期计时观测实现：我们旨在持续追踪这些脉冲星的自转相位，并提升测得自行（proper motions）的数量与精度。所有过往数据的全面分析仍在进行中：我们近期发现了一颗新脉冲星（47TucZ）及两颗极具潜力的候选体，确认了一个已知天体（47TucX），并测定了另外三颗脉冲星的计时解——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，以及新发现的双星系统47 Tuc Y。这使得我们能够利用钱德拉（Chandra）X射线望远镜识别出这三颗脉冲星，并通过哈勃空间望远镜（HST）的光学数据确定47TucY的伴星。杜鹃座47中的部分脉冲星现已可通过费米（Fermi）伽马射线望远镜探测到，但我们仍需持续更新其射电星历表。