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.