Dark matter annihilation in the milky way galaxy: effects of baryonic compression

If the dark matter (DM), which is considered to constitute most of the mass of galaxies, is made of supersymmetric particles, the central region of our Galaxy should emit gamma rays produced by their annihilation. We use detailed models of the Milky Way to make accurate estimates of continuum gamma-ray fluxes. We argue that the most important effect, which was previously neglected, is the compression of the dark matter due to the infall of baryons to the galactic center: it boosts the expected signal by a factor 1000. To illustrate this effect, we computed the expected gamma fluxes in the minimal supergravity scenario. Our models predict that the signal could be detected at high confidence levels by imaging atmospheric C erenkov telescopes assuming that neutralinos make up most of the DM in the Universe.