Classification of gamma-ray targets for velocity-dependent and subhalo-boosted dark-matter annihilation

Understand

Gamma-ray observations have long been used to constrain the properties of dark matter (DM), with a strong focus on weakly interacting massive particles annihilating through velocity-independent processes.

• However, in the absence of clear-cut observational evidence for the simplest candidates, the interest of the community in more complex DM scenarios involving a velocity-dependent cross-section has been growing steadily over the past few years.
• We present the first systematic study of velocity-dependent DM annihilation (in particular $p$-wave annihilation and Sommerfeld enhancement) in a variety of astrophysical objects, not only including the well-studied Milky Way dwarf satellite galaxies, but nearby dwarf irregular galaxies and local galaxy clusters as well.
• Particular attention is given to the interplay between velocity dependence and DM halo substructure.