Searching for Millisecond Pulsars: Surveys, Techniques and Prospects

TL;DR

Recent advances in radio telescope technology and targeted gamma-ray source searches have significantly increased the discovery rate of millisecond pulsars in the Galactic field, surpassing those in globular clusters.

Contribution

This paper reviews recent survey techniques, discoveries, and future prospects for millisecond pulsar searches, highlighting the impact of new instrumentation and targeted gamma-ray source identification.

Findings

Over 50 new millisecond pulsars discovered in five years

Current sample exceeds 200 pulsars, outnumbering those in globular clusters

Advancements in survey methods have revolutionized pulsar detection

Abstract

Searches for millisecond pulsars (which we here loosely define as those with periods $<$ 20 ms) in the Galactic field have undergone a renaissance in the past five years. New or recently refurbished radio telescopes utilizing cooled receivers and state-of-the art digital data acquisition systems are carrying out surveys of the entire sky at a variety of radio frequencies. Targeted searches for millisecond pulsars in point sources identified by the {\it Fermi} Gamma-ray Space Telescope have proved phenomenally successful, with over 50 discoveries in the past five years. The current sample of millisecond pulsars now numbers almost 200 and, for the first time in 25 years, now outnumbers their counterparts in Galactic globular clusters. While many of these searches are motivated to find pulsars which form part of pulsar timing arrays, a wide variety of interesting systems are now being found. Following a brief overview of the millisecond pulsar phenomenon, we describe these searches and present some of the highlights of the new discoveries in the past decade. We conclude with predictions and prospects for ongoing and future surveys.