Effective $J$-factors for Milky Way dwarf spheroidal galaxies with
  velocity-dependent annihilation
  We calculate the effective $J$-factors, which determine the strength of
indirect detection signals from dark matter annihilation, for 25 dwarf
spheroidal galaxies (dSphs). We consider several well-motivated assumptions for
the relative velocity dependence of the dark matter annihilation cross section:
$\sigma_A v$: $s$-wave (velocity independent), $p$-wave ($\sigma_A v \propto
v^2$), $d$-wave ($\sigma_A v \propto v^4$), and Sommerfeld-enhancement in the
Coulomb limit ($\sigma_A v \propto 1/v$). As a result we provide the largest
and most updated sample of J-factors for velocity-dependent annihilation
models. For each scenario, we use Fermi-LAT gamma-ray data to constrain the
annihilation cross section. Due to the assumptions made in our gamma-ray data
analysis, our bounds are comparable to previous bounds on both the $p$-wave and
Sommerfeld-enhanced cross sections using dSphs. Our bounds on the $d$-wave
cross section are the first such bounds using indirect detection data.
