Galactic dark matter search via phenomenological astrophysics modeling
  Previous searches for the $\gamma$-ray signatures of annihilating galactic
dark matter used predefined spatial templates to describe the background of
$\gamma$-ray emission from astrophysical processes like cosmic ray
interactions. In this work, we aim to establish an alternative approach, in
which the astrophysical components are identified solely by their spectral and
morphological properties. To this end, we adopt the recent reconstruction of
the diffuse $\gamma$-ray sky from Fermi data by the D$^{3}$PO algorithm and the
fact that more than 90\% of its flux can be represented by only two spectral
components, resulting form the dense and dilute interstellar medium. Under
these presumptions, we confirm the reported DM annihilation-like signal in the
inner Galaxy and derive upper limits for dark matter annihilation cross
sections. We investigate whether the DM signal could be a residual of the
simplified modeling of astrophysical emission by inspecting the morphology of
the regions, which favor a dark matter component. The central galactic region
favors strongest for such a component with the expected spherically symmetric
and radially declining profile. However, astrophysical structures, in
particular sky regions which seem to host most of the dilute interstellar
medium, obviously would benefit from a DM annihilation-like component as well.
Although these regions do not drive the fit, they warn that a more detailed
understanding of astrophysical $\gamma$-ray emitting processes in the galactic
center region are necessary before definite claims about a DM annihilation
signal can be made. The regions off the Galactic plane actually disfavor the
best fit DM annihilation cross section from the inner Galactic region unless
the radial decline of the Galactic DM density profile in the outer regions is
significantly steeper than that usually assumed.
