Detection of neutralino annihilation photons from external galaxies - art.no. 023514

We consider neutralino annihilation in dense extragalactic systems known to be dominated by dark matter, in particular M87 and several local dwarf sph eroidal galaxies. These annihilations can produce energetic gamma rays whic h may be visible to atmospheric Cerenkov telescopes. We explore the supersy mmetric parameter space, and compute the expected flux of gamma rays coming from these objects. It is shown that some parts of the parameter space lea d to a signal observable with the next generation of Cerenkov telescopes, p rovided the supersymmetric dark matter has a clumpy structure, as may be ex pected in a hierarchical scenario for structure formation.