Pulsars and Millisecond Pulsars V: Observational Census of Globular Cluster and Field Pulsars

This fifth paper of a series on pulsars and millisecond pulsars (MSPs) looks at the observational side of the problem. We review the facilities that detect pulsars in different wavebands and the catalogues that collect their parameters, and we compare the pulsars of globular clusters (GCs) with those of the Galactic field (GF), using version 2.9.0 of the ATNF Pulsar Catalogue and the list of 372 GC pulsars in 46 clusters maintained by P. Freire. MSPs make up 94% of the GC pulsars and 15% of the GF pulsars, and GCs host 36% of the MSPs known in the Milky Way. Binary MSPs in GCs have shorter orbits than those in the GF, with median orbital periods of 1.1 and 4.8 days, and are more often eccentric, 16% against 5% with e > 0.1. The isolated fraction of GC MSPs is 86% in core-collapsed clusters and 42% in the others. The spin periods of the two populations differ only when the comparison is restricted to fully recycled MSPs, and 45% of the GC MSPs with a measured period derivative show a negative value, so that fields and ages derived from them are biased. We relate these results to the seven evolutionary scenarios of this series and to current simulations, and end with nine observational benchmarks for cluster models that follow pulsars.