  Dwarf spheroidals are low-luminosity satellite galaxies of the Milky Way
highly dominated by dark matter (DM). Therefore, they are prime targets to
search for signals from dark matter annihilation using gamma-ray observations.
While the typical assumption is that the dark matter density profile of these
satellite galaxies can be described by a spherical symmetric
Navarro-Frenk-White (NFW) profile, recent observational data of stellar
kinematics suggest that the DM halos around these galaxies are better described
by axisymmetric profiles. Motivated by such evidence, we analyse about seven
years of PASS8 Fermi data for seven classical dwarf galaxies, including Draco,
adopting both the widely used NFW profile and observationally-motivated
axisymmetric density profiles. For four of the selected dwarfs (Sextans,
Carina, Sculptor and Fornax) axisymmetric mass models suggest a cored density
profile rather than the commonly adopted cusped profile. We found that upper
limits on the annihilation cross section for some of these dwarfs are
significantly higher than the ones achieved using an NFW profile. Therefore,
upper limits in the literature obtained using spherical symmetric cusped
profiles, such as the NFW, might be overestimated. Our results show that it is
extremely important to use observationally motivated density profiles going
beyond the usually adopted NFW in order to obtain accurate constraints on the
dark matter annihilation cross section.
