English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The Fermi Large Area Telescope has observed an excess of ~GeV energy gammarays from the center of the Milky Way, which may arise from near-thermal darkmatter annihilation. Firmly establishing the dark matter origin for this excessis however complicated by challenges in modeling diffuse cosmic-ray foregroundsas well as unresolved astrophysical sources, such as millisecond pulsars.Non-Poissonian Template Fitting (NPTF) is one statistical technique that haspreviously been used to show that at least some fraction of the GeV excess islikely due to a population of dim point sources. These results were recentlycalled into question by Leane and Slatyer (2019), who showed that a syntheticdark matter annihilation signal injected on top of the real Fermi data is notrecovered by the NPTF procedure. In this work, we perform a dedicated study ofthe Fermi data and explicitly show that the central result of Leane and Slatyer(2019) is likely driven by the fact that their choice of model for the Galacticforeground emission does not provide a sufficiently good description of thedata. We repeat the NPTF analyses using a state-of-the-art model for diffusegamma-ray emission in the Milky Way and introduce a novel statisticalprocedure, based on spherical-harmonic marginalization, to provide an improveddescription of the Galactic diffuse emission in a data-driven fashion. Withthese improvements, we find that the NPTF results continue to robustly favorthe interpretation that the Galactic Center excess is due, in part, tounresolved astrophysical point sources across the analysis variations that wehave explored.

Foreground Mismodeling and the Point Source Explanation of the Fermi Galactic Center Excess