Constraining the luminosity function parameters and population size of radio pulsars in globular clusters

TL;DR

This paper uses Bayesian methods to estimate the luminosity function parameters and the total population size of radio pulsars in globular clusters, based on observational data and diffuse emission measurements.

Contribution

It introduces a Bayesian framework to constrain pulsar luminosity distribution parameters and population size in globular clusters, incorporating flux data and diffuse emission.

Findings

Estimated 133$^{+101}_{-58}$ pulsars in Terzan 5 with 95.45% credibility

Beaming effects could double the true pulsar population

Method provides constraints on luminosity function parameters

Abstract

The luminosity distribution of Galactic radio pulsars is believed to be log-normal in form. Applying this functional form to populations of pulsars in globular clusters, we employ Bayesian methods to explore constraints on the mean and standard deviation of the function, as well as the total number of pulsars in the cluster. Our analysis is based on an observed number of pulsars down to some limiting flux density, measurements of flux densities of individual pulsars, as well as diffuse emission from the direction of the cluster. We apply our analysis to Terzan 5 and demonstrate, under reasonable assumptions, that the number of potentially observable pulsars is in a 95.45% credible interval of 133$^{+101}_{-58}$. Beaming considerations would increase the true population size by approximately a factor of two.