A MeerKAT view of the pulsars in the globular cluster NGC 6522

Abstract

We present the results of observations aimed at discovering and studying pulsars in the core-collapsed globular cluster (GC) NGC 6522 performed by the MeerTIME and TRAPUM Large Survey Project with the MeerKAT telescope. We have discovered two new isolated pulsars bringing the total number of known pulsars in the cluster to six. PSR J1803−3002E is a mildly recycled pulsar with a spin period of 17.9 ms, while pulsar PSR J1803−3002F is a slow pulsar with a spin period of 148.1 ms. The presence of isolated and slow pulsars is expected in NGC 6522, and confirms the predictions of previous theories for clusters at this stage in evolution. We further present a tentative timing solution for the millisecond pulsar (MSP) PSR J1803−3002C combining older observations taken with the Parkes 64 m radio telescope, Murriyang. This solution implies a relatively young characteristic age of the pulsar in contrast with the old age of the GC. The presence of a slow pulsar and an apparently young MSP, both rare in GCs, suggests that their formation might be linked to the evolutionary stage of the cluster.