Extracting the unresolved pulsar contribution to the gamma-ray background

TL;DR

This paper introduces a statistical method to quantify the contribution of unresolved pulsars to the gamma-ray background using photon time series analysis, demonstrating detection capabilities with Fermi data.

Contribution

The paper presents a novel, robust framework for identifying unresolved pulsar populations in gamma-ray data, adaptable to complex periodicity searches.

Findings

Detects pulsar contributions as small as 0.1% of gamma-ray background

Sensitive to pulsar fluxes >~1E-10 cm^-2 s^-1

Applicable to all-sky surveys and specific regions like the Galactic center

Abstract

We present a statistical framework which can be used to determine the contribution of an unresolved population of pulsars to the gamma-ray background. This formalism is based on the joint analysis of photon time series over extended regions of the sky. We demonstrate the robustness of this technique in controlled simulations of pulsar populations, and show that the Fermi Gamma-ray Space Telescope can be used to detect a pulsar contribution as small as 0.1% of the gamma-ray background. This technique is sensitive to pulsar populations with photon fluxes greater than ~1E-10 cm^-2 s^-1. The framework is extensible to arbitrarily complex searches for periodicity and can therefore be tailored to specific applications such as all-sky surveys and studies of the Galactic center and globular clusters.