  In this Letter, we study the gamma-ray signatures subsequent to the
production of a Higgs boson in space by dark matter annihilations. We
investigate the cases where the Higgs boson is produced at rest or slightly
boosted and show that such configurations can produce characteristic bumps in
the gamma-ray data. These results are relevant in the case of the Standard
Model-like Higgs boson provided that the dark matter mass is about 63 GeV, 109
GeV or 126 GeV, but can be generalised to any other Higgs boson masses. Here,
we point out that it may be worth looking for a 63 GeV line since it could be
the signature of the decay of a Standard Model-like Higgs boson produced in
space, as in the case of a di-Higgs final state if m_DM ~ 126 GeV. We show that
one can set generic constraints on the Higgs boson production rates using its
decay properties. In particular, using the Fermi-LAT data from the galactic
center, we find that the dark matter annihilation cross section into gamma + a
Standard Model-like Higgs boson produced at rest or near rest cannot exceed
<sigma v> ~ a few 10^-25 cm^3/s or <sigma v> ~ a few 10^-27 cm^3/s
respectively, providing us with information on the Higgs coupling to the dark
matter particle. We conclude that Higgs bosons can indeed be used as messengers
to explore the dark matter mass range.
