Parkes observations for project P1168 semester 2023APRS_10

We discovered seven pulsars in the globular cluster Terzan 1 with the Green Bank Telescope (GBT), the first pulsars to be found in this cluster. The discoveries include five fully-recycled millisecond pulsars (MSPs) with spin periods between 3 and 6 ms, an 11-ms MSP, and a pulsar with an unusually long spin period of 134 ms. Our preliminary timing suggested that all seven are likely isolated pulsars, consistent with Terzan 1 being a core-collapsed globular cluster. The 134-ms pulsar is an especially interesting discovery in the context of pulsar formation via electron-capture rather than core-collapse supernovae. We observed Terzan 1 at Parkes with the UWL receiver in 2022OCT to test whether the pulsars could be detected and thus timed at Parkes. All seven pulsars are significantly detected in both observations. We propose a year-long timing campaign with Parkes/UWL to obtain phase-connected timing solutions for these pulsars; we request continuing status to continue these timing observations through 2023OCT. To refine the timing parameters and probe the pulsars' acceleration in the cluster potential, we will extend phase connection beyond one year using the 2022OCT observations, and we will attempt to phase connect back to the original GBT discovery pointings. 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.