  We propose the existence of a hidden or dark sector besides the standard
model (SM) of particle physics, whose members (both fermionic and bosonic) obey
a local SU(2)$_{\rm H}$ gauge symmetry while behaving like a singlet under the
SM gauge group. However, the fermiomic fields of the dark sector also possess
another global U(1)$_{\rm H}$ symmetry which remains unbroken. The local
SU(2)$_{\rm H}$ invariance of the dark sector is broken spontaneously when a
scalar field in this sector acquires a vacuum expectation value (VEV) and
thereby generating masses to the dark gauge bosons and dark fermions charged
under the SU(2)$_{\rm H}$. The lightest fermion in this dark SU(2)$_{\rm H}$
sector can be a potential dark matter candidate. We first examine the viability
of the model and constrain the model parameter space by theoretical constraints
such as vacuum stability and by the experimental constraints such as PLANCK
limit on relic density, LHC data, limits on spin independent scattering
cross-section from dark matter direct search experiments etc. We then
investigate the gamma rays from the pair annihilation of the proposed dark
matter candidate at the Galactic Centre region. We also extend our calculations
of gamma rays flux for the case of dwarf galaxies and compare the signatures of
gamma rays obtained from these astrophysical sites.
