Dwarf galaxy annihilation and decay emission profiles for dark matter experiments

TL;DR

This paper assesses dark matter density profiles in 20 dwarf galaxies to improve gamma-ray search strategies for dark matter annihilation and decay, quantifying uncertainties and optimizing detection prospects.

Contribution

It provides a uniform analysis of stellar-kinematic data to predict dark matter signals in dwarf galaxies, reducing uncertainties in gamma-ray search sensitivities.

Findings

Current data can predict annihilation signals within a factor of a few for ultra-faint dwarfs.

Signal localization for classical dwarfs can reach about 20% accuracy.

Results inform the design of more sensitive dark matter detection experiments.

Abstract

Gamma-ray searches for dark matter annihilation and decay in dwarf galaxies rely on an understanding of the dark matter density profiles of these systems. Conversely, uncertainties in these density profiles propagate into the derived particle physics limits as systematic errors. In this paper we quantify the expected dark matter signal from 20 Milky Way dwarfs using a uniform analysis of the most recent stellar-kinematic data available. Assuming that the observed stellar populations are equilibrium tracers of spherically-symmetric gravitational potentials that are dominated by dark matter, we find that current stellar-kinematic data can predict the amplitudes of annihilation signals to within a factor of a few for the ultra-faint dwarfs of greatest interest. On the other hand, the expected signal from several classical dwarfs (with high-quality observations of large numbers of member stars) can be localized to the ~20% level. These results are important for designing maximally sensitive searches in current and future experiments using space and ground-based instruments.