Gamma-rays from Heavy Minimal Dark Matter
  We consider the annihilation into gamma rays of Minimal Dark Matter
candidates in the fermionic 5-plet and scalar 7-plet representations of
$SU(2)_L$, taking into account both the Sommerfeld effect and the internal
bremsstrahlung. Assuming the Einasto profile, we show that present measurements
of the Galactic Center by the H.E.S.S. instrument exclude the 5-plet and 7-plet
as the dominant form of dark matter for masses between 1 TeV and 20 TeV, in
particular, the 5-plet mass leading to the observed dark matter density via
thermal freeze-out. We also discuss prospects for the upcoming Cherenkov
Telescope Array, which will be able to probe even heavier dark matter masses,
including the scenario where the scalar 7-plet is thermally produced.
