Defining Millisecond Pulsars

TL;DR

This paper redefines millisecond pulsars by analyzing their period distribution with Gaussian mixture models, suggesting a more precise cutoff at approximately 16 milliseconds instead of the traditional 20-30 ms.

Contribution

The study applies Gaussian mixture modeling to pulsar data to refine the classification criteria for millisecond pulsars.

Findings

MSPs are better defined by P_s ≲ 16 ms

Gaussian mixture models reveal distinct pulsar clusters

Revised MSP cutoff improves classification accuracy

Abstract

Millisecond pulsars (MSP) are an important subclass of rotation powered pulsars (RPP), traditionally defined as those with $P_s < 20-30$~ms and $B_s \lesssim 10^{10}$~G. We re-examine this definition by applying Gaussian mixture model (GMM) analysis to identify distinct clusters within the RPP population and find that the MSPs appear to be better demarcated by the condition $\mathbf{P_s \lesssim 16}$~ms.