Annihilations from the Galactic Centre
  A massive black hole is present at the centre of our galaxy and inevitably accretes dark matter particles, creating a region of very high particle density. The annihilation rate is enhanced with a large number of e+e- pairs produced either directly or by successive decays of mesons. We evaluate the synchrotron emission (and self-absorption) associated with the propagation of these particles through the galactic magnetic field and give constraints on the values of mass and cross section of the dark matter particles. 
G.Bertone (1), G.Sigl (2), J.Silk (1) ((1) Department of Astrophysics,   University of Oxford; (2) Institut d'Astrophysique ...