Dark matter vs. Pulsars: Catching the impostor

TL;DR

This paper discusses whether the observed GeV gamma-ray excess near the Galactic Centre is more likely caused by pulsars, specifically millisecond pulsars, rather than dark matter annihilation, highlighting the potential of pulsar populations as an alternative explanation.

Contribution

It presents an argument that pulsars, especially hard millisecond pulsars, remain a viable explanation for the Galactic Centre gamma-ray excess, challenging the dark matter interpretation.

Findings

Pulsars could explain the GeV excess near the Galactic Centre.

Recent pulsar catalogues support the pulsar hypothesis.

Dark matter explanation is not definitively favored over pulsars.

Abstract

Evidence of excess GeV emission nearly coinciding with the Galactic Centre has been interpreted as a possible signature of annihilating dark matter. In this paper, we argue that it seems too early to discard pulsars as a viable explanation for the observed excess. On the heels of the recently released Second Fermi LAT Pulsar Catalogue (2FPC), it is still possible that a population of hard (Gamma < 1) millisecond pulsars (MSPs) either endemic to the innermost region or part of a larger nascent collection of hard MSPs that appears to be emerging in the 2FPC could explain the GeV excess near the Galactic Centre.