Dark matter line search using a joint analysis of dwarf galaxies with the Fermi Gamma-ray Space Telescope

TL;DR

This study uses Fermi telescope data and a novel statistical approach to search for gamma-ray lines from dark matter annihilation in dwarf galaxies, setting new upper limits on the annihilation cross section.

Contribution

It introduces a new joint analysis method that incorporates spatial and spectral photon information across multiple dwarf galaxies for dark matter searches.

Findings

No gamma-ray line detected between 10 GeV and 1 TeV.

Upper limit on dark matter annihilation cross section at 130 GeV is 3.9 x 10^-26 cm^3/s.

Systematic uncertainties affect the cross section limits.

Abstract

We perform a joint analysis of dwarf galaxy data from the Fermi Gamma-ray Space Telescope in search of dark matter annihilation into a gamma-ray line. We employ a novel statistical method that takes into account the spatial and spectral information of individual photon events from a sample of seven dwarf galaxies. Dwarf galaxies show no evidence of a gamma-ray line between 10 GeV and 1 TeV. The subsequent upper limit on the annihilation cross section to a two-photon final state is 3.9(+7.1)(-3.7) x 10^-26 cm^3/s at 130 GeV, where the errors reflect the systematic uncertainty in the distribution of dark matter within the dwarf galaxies.