Probing Globular Cluster with MeerKAT and FAST: A Pulsar Polarization Census
Abstract
Only one globular cluster (GC), 47 Tuc, has been found to contain intracluster medium, with an electron density 100 times higher than that of the ISM in its vicinity. The characteristics of this intracluster medium are closely related to GC evolution and the compact objects within. However, significant knowledge gaps remain regarding the ionized gas content of GCs, particularly in Galactic halo clusters. We carried out a polarization census of GC pulsars using MeerKAT and FAST. This first combined effort of observations from these two major radio telescopes resulted in high signal-to-noise ratio, full polarization pulse profiles for 43 pulsars in 8 GCs, doubling the number of rotation measures (RMs) known in these clusters. The accuracy of dispersion measures (DMs) was improved by a factor of 8 compared to previous publications. No intracluster medium was found, and at least two halo GCs showed more stringent upper limits on electron density than that detected in 47 Tuc. The surprising barrenness of GCs suggests effective gas removal mechanisms, such as strong winds from millisecond pulsars and/or ionizing radiation from post-AGB stars and young white dwarfs.
Keywords
Cite
@article{arxiv.2503.08291,
title = {Probing Globular Cluster with MeerKAT and FAST: A Pulsar Polarization Census},
author = {Lei Zhang and Federico Abbate and Di Li and Andrea Possenti and Matthew Bailes and Alessandro Ridolfi and Paulo C. C. Freire and Scott M. Ransom and Yong-Kun Zhang and Meng Guo and Meng-Meng Ni and Jia-Le Hu and Yi Feng and Pei Wang and Jie Zhang and Qi-Jun Zhi},
journal= {arXiv preprint arXiv:2503.08291},
year = {2025}
}