Dark matter and pulsar signals for Fermi LAT, PAMELA, ATIC, HESS and WMAP data

TL;DR

This paper examines gamma-ray and cosmic-ray data from multiple observatories to evaluate dark matter and pulsar models, finding all scenarios fit the data well and highlighting potential signals for dark matter annihilation in the galactic center.

Contribution

It compares dark matter and pulsar explanations for gamma-ray and positron data, considering various halo profiles and uncertainties, and discusses potential gamma-ray signals for dark matter.

Findings

All three scenarios fit the data well.

Pulsar models are flexible across energy spectra.

Cusped halo profiles could produce detectable gamma-ray signals.

Abstract

We analyze new diffuse gamma-ray data from the Fermi Gamma-ray Space Telescope, which do not confirm an excess in the EGRET data at galactic mid-latitudes, in combination with measurements of electron and positron fuxes from PAMELA, Fermi and HESS within the context of three possible sources: dark matter (DM) annihilation or decay into charged leptons, and a continuum distribution of pulsars. We allow for variations in the backgrounds, consider several DM halo profiles, and account for systematic uncertainties in data where possible. We find that all three scenarios represent the data well. The pulsar description holds for a wide range of injection energy spectra. We compare with ATIC data and the WMAP haze where appropriate, but do not fit these data since the former are discrepant with Fermi data and the latter are subject to large systematic uncertainties. We show that for cusped halo profiles, Fermi could observe a spectacular gamma-ray signal of DM annihilation from the galactic center while seeing no excess at mid-latitudes.