Parkes observations for project P1168 semester 2024APRS_01

We discovered seven pulsars in the globular cluster Terzan 1 with the Green Bank Telescope (GBT) and have been timing them over the last year with the Parkes Telescope. The discoveries include five fully-recycled millisecond pulsars (MSPs) with spin periods between 3 and 6 ms, a partially-recycled 11-ms MSP, and a pulsar with an unusually long spin period of 134 ms. With our Parkes timing campaign, we have confirmed that all seven pulsars are isolated, consistent with Terzan 1 being a core-collapsed globular cluster. The 134-ms pulsar has a characteristic age of 23 Myr and is thus an especially interesting discovery in the context of pulsar formation via electron-capture rather than core-collapse supernovae. (We are preparing a paper detailing these results and will submit it in January or February 2024.) We propose to continue timing Terzan 1 at Parkes in order to obtain long-baseline timing solutions, which will yield measurements of proper motion and potentially additional spin derivatives that together can be used to probe the cluster dynamics, constrain intrinsic spin properties of the pulsars, and confirm the young vs. old nature of the 134 ms pulsar. In addition to timing, we will probe the pulsars' polarization properties and the Galactic magnetic field in the direction of Terzan 1; and the proposed observations will also be searched for new pulsars that may have been missed in previous observations. We request continuing status to continue these timing observations through 2024OCT.

本研究借助绿岸望远镜（Green Bank Telescope, GBT）在球状星团Terzan 1中发现了7颗脉冲星，并于过去一年间利用帕克斯望远镜（Parkes Telescope）对其开展持续计时观测。本次发现的脉冲星包含5颗自转周期介于3至6毫秒之间的完全再循环毫秒脉冲星（millisecond pulsars, MSPs）、1颗自转周期为11毫秒的部分再循环毫秒脉冲星，以及1颗自转周期长达134毫秒的特殊脉冲星。通过帕克斯望远镜的计时观测项目，我们已确认这7颗脉冲星均为孤立脉冲星，这与Terzan 1属于核塌缩球状星团的结论相符。这颗134毫秒脉冲星的特征年龄为23百万年（Myr），在通过电子俘获而非核塌缩超新星形成脉冲星的研究框架下，该发现尤为引人关注。（我们正撰写详细阐述这些结果的论文，计划于2024年1月或2月提交。）我们提议继续利用帕克斯望远镜对Terzan 1开展计时观测，以获取长基线计时解，进而实现多项科学目标：测量脉冲星的自行、获取潜在的额外自转导数参数；上述数据可用于探究星团动力学、约束脉冲星的固有自转特性，以及验证这颗134毫秒脉冲星的年轻/年老属性。除计时观测外，我们还将研究这些脉冲星的偏振特性，并探测Terzan 1方向的银河磁场；同时，我们将对本次计划的观测数据进行搜寻，以寻找此前观测中可能遗漏的新脉冲星。我们申请延续观测状态，以在2024年10月前持续开展上述计时观测。