Young Pulsars and the Galactic Center GeV Gamma-ray Excess

TL;DR

This paper proposes that young gamma-ray pulsars, originating from supernovae near the Galactic center, can produce a gamma-ray excess similar to that attributed to dark matter, explaining the observed spatial and spectral features.

Contribution

It demonstrates that a population of young pulsars with evolving spectra can account for the Galactic center gamma-ray excess, challenging the dark matter interpretation.

Findings

Young pulsars can produce a gamma-ray excess similar to observations.

Pulsar populations with age-dependent spectra match the excess's morphology.

Unresolved pulsars contribute significantly to the observed signal.

Abstract

Studies of Fermi data indicate an excess of GeV gamma rays around the Galactic center (GC), possibly due to dark matter. We show that young gamma-ray pulsars can yield a similar signal. First, a high concentration of GC supernovae naturally leads to a population of kicked pulsars symmetric about the GC. Second, while very-young pulsars with soft spectra reside near the Galactic plane, pulsars with spectra that have hardened with age accumulate at larger angles. This combination, including unresolved foreground pulsars, traces the morphology and spectrum of the Excess.