The TeV Gamma-Ray Luminosity of the Milky Way and the Contribution of H.E.S.S. Unresolved Sources to Very High Energy Diffuse Emission

H.E.S.S. has recently completed the first systematic survey of the Galactic plane in the TeV energy domain. We analyze the flux, latitude, and longitude distributions of γ-ray sources observed by H.E.S.S. in order to infer the properties of the Galactic TeV source population. We show that the total Milky Way luminosity in the 1–100 TeV energy range is $L_{MW}={1.7}_{-0.4}^{+0.5}\times {10}^{37}erg{s}^{-1}$. Evaluating the cumulative flux expected at Earth by the considered population, we show that H.E.S.S. unresolved sources provide a relevant contribution to the diffuse Galactic emission. Finally, in the hypothesis that the majority of bright sources detected by H.E.S.S. are powered by pulsar activity, like, e.g., pulsar wind nebulae or TeV halos, we estimate the main properties of the pulsar population.