GeV excess and phenomenological astrophysics modeling

Xiaoyuan Huang,Torsten Enßlin,Marco Selig

doi:10.1088/1742-6596/718/4/042029

Abstract

Predefined spatial templates to describe the background of γ-ray emission from astrophysical processes, like cosmic ray interactions, are used in previous searches for the γ-ray signatures of annihilating galactic dark matter. In this proceeding, we investigate the GeV excess in the inner Galaxy using an alternative approach, in which the astrophysical components are identified solely by their spectral and morphological properties. We confirm the reported GeV excess and derive related parameters for dark matter interpretation, which are consistent with previous results. We investigate the morphology of this spectral excess as preferred by the data only. This emission component exhibits a central Galaxy cusp as expected for a dark matter annihilation signal. However, Galactic disk regions with a morphology of that of the hot interstellar medium also host such a spectral component. This points to a possible astrophysical origin of the excess and requests a more detailed understanding of astrophysical γ-ray emitting processes in the galactic center region before definite claims about a dark matter annihilation signal can be made.

Highlights

Identifying its annihilation signatures is a promising way to probe the nature of dark matter (DM)
Galactic disk regions with a morphology of that of the hot interstellar medium host such a spectral component. This points to a possible astrophysical origin of the excess and requests a more detailed understanding of astrophysical γ-ray emitting processes in the galactic center region before definite claims about a dark matter annihilation signal can be made
The Galactic Center (GC) region is ideal with respect to the first two conditions, due to supernovae explosions injecting cosmic rays (CRs) into the interstellar medium (ISM) and compact sources of high energy particles and radiation, it exhibits significant amounts of astrophysical γ-ray emissions [1]

Summary

Introduction

Identifying its annihilation signatures is a promising way to probe the nature of dark matter (DM). We investigate the GeV excess in the inner Galaxy using an alternative approach, in which the astrophysical components are identified solely by their spectral and morphological properties.

Results

Conclusion