Dark matter annihilation and decay from non-spherical dark halos in the
  Galactic dwarf satellites
  The dwarf spheroidal galaxies (dSphs) in the Milky Way are the primary
targets in the indirect searches for particle dark matter. To set robust
constraints on candidate of dark matter particles, understanding the dark halo
structure of these systems is of substantial importance. In this paper, we
first evaluate the astrophysical factors for dark matter annihilation and decay
for 24 dSphs, with taking into account a non-spherical dark halo, using
generalized axisymmetric mass models based on axisymmetric Jeans equations.
First, from a fitting analysis of the most recent kinematic data available, our
axisymmetric mass models are a much better fit than previous spherical ones,
thus, our work should be the most realistic and reliable estimator for
astrophysical factors. Secondly, we find that among analysed dSphs, the
ultra-faint dwarf galaxies Triangulum II and Ursa Major II are the most
promising but large uncertain targets for dark matter annihilation while the
classical dSph Draco is the most robust and detectable target for dark matter
decay. It is also found that the non-sphericity of luminous and dark components
influences the estimate of astrophysical factors, even though these factors
largely depend on the sample size, the prior range of parameters and the
spatial extent of the dark halo. Moreover, owing to these effects, the
constraints on the dark matter annihilation cross-section are more conservative
than those of previous spherical works. These results are important for
optimizing and designing dark matter searches in current and future
multi-messenger observations by space and ground-based telescopes.
