A 1.4-GHz Arecibo Survey for Pulsars in Globular Clusters

TL;DR

This survey used the Arecibo telescope to discover 13 new millisecond pulsars in 5 globular clusters, significantly increasing known pulsars, especially very fast-spinning and short orbital period systems, enhancing understanding of cluster pulsar populations.

Contribution

The paper reports the discovery of 13 new pulsars in globular clusters, nearly doubling the known pulsar population in these clusters, with advanced search techniques enabling detection of fast and binary pulsars.

Findings

Discovered 11 new millisecond pulsars and 2 candidates.

Most new pulsars are in binary systems, with some eclipsing.

Detected more very fast-spinning and short orbital period pulsars than previous surveys.

Abstract

We have surveyed all 22 known Galactic globular clusters observable with the Arecibo radio telescope and within 70kpc of the Sun for radio pulsations at ~1.4GHz. Data were taken with the Wideband Arecibo Pulsar Processor, which provided the large bandwidth and high time and frequency resolution needed to detect fast-spinning, faint pulsars. We have also employed advanced search techniques to maintain sensitivity to short orbital period binaries. These searches have discovered 11 new millisecond pulsars and 2 promising candidates in 5 clusters, almost doubling the population of pulsars in the Arecibo-visible globular clusters. Ten of these new pulsars are in binary systems, and 3 are eclipsing. This survey has discovered significantly more very fast-spinning pulsars (P_spin <~ 4ms) and short orbital period systems (P_orb <~ 6hr) than previous surveys of the same clusters. We discuss some properties of these systems, as well as some characteristics of the globular cluster pulsar population in general, particularly its luminosity distribution.