  Relativistic hydrodynamical simulations of the eccentric gamma-ray binary
HESS J0632$+$057, show that the energy of a putative pulsar wind should
accumulate in the binary surroundings between periastron and apastron, being
released by fast advection close to apastron. To assess whether this could lead
to a maximum of the non-thermal emission before apastron, we derive simple
prescriptions for the non-thermal energy content, the radiation efficiency, and
the impact of energy losses on non-thermal particles, in the simulated
hydrodynamical flow. These prescriptions are used to estimate the non-thermal
emission in radio, X-rays, GeV, and TeV, from the shocked pulsar wind in a
binary system simulated using a simplified 3-dimensional scheme for several
orbital cycles. Lightcurves at different wavelengths are derived, together with
synthetic radio images for different orbital phases. The dominant peak in the
computed lightcurves is broad and appears close to, but before, apastron. This
peak is followed by a quasi-plateau shape, and a minor peak only in gamma rays
right after periastron. The radio maps show ejection of radio blobs before
apastron in the periastron-apastron direction. The results show that a scenario
with a highly eccentric high-mass binary hosting a young pulsar can explain the
general phenomenology of HESS J0632$+$057: despite its simplicity, the adopted
approach yields predictions that are robust at a semi-quantitative level and
consistent with multiwavelength observations.
