Indirect detection Dark matter

collage of 6 cluster collisions dark matter maps. clusters observed in study of how dark matter in clusters of galaxies behaves when clusters collide.




video potential gamma-ray detection of dark matter annihilation around supermassive black holes. (duration 3:13, see file description.)

indirect detection experiments search products of self-annihilation or decay of dark matter particles in outer space. example, in regions of high dark matter density (e.g. centre of our galaxy) 2 dark matter particles annihilate produce gamma rays or standard model particle-antiparticle pairs. alternatively if dark matter particle unstable, decay standard model (or other) particles. these processes detected indirectly through excess of gamma rays, antiprotons or positrons emanating high density regions in our galaxy or others. major difficulty inherent in such searches there various astrophysical sources can mimic signal expected dark matter, , multiple signals required conclusive discovery.

a few of dark matter particles passing through sun or earth may scatter off atoms , lose energy. dark matter may accumulate @ center of these bodies, increasing chance of collision/annihilation. produce distinctive signal in form of high-energy neutrinos. such signal strong indirect proof of wimp dark matter. high-energy neutrino telescopes such amanda, icecube , antares searching signal. detection ligo in september 2015 of gravitational waves, opens possibility of observing dark matter in new way, particularly if form of primordial black holes.

many experimental searches have been undertaken such emission dark matter annihilation or decay, examples of follow. energetic gamma ray experiment telescope observed more gamma rays in 2008 expected milky way, scientists concluded due incorrect estimation of telescope s sensitivity.

the fermi gamma-ray space telescope searching similar gamma rays. in april 2012, analysis of available data large area telescope instrument produced statistical evidence of 130 gev signal in gamma radiation coming center of milky way. wimp annihilation seen probable explanation.

at higher energies, ground-based gamma-ray telescopes have set limits on annihilation of dark matter in dwarf spheroidal galaxies , in clusters of galaxies.

the pamela experiment (launched 2006) detected excess positrons. dark matter annihilation or pulsars. no excess antiprotons observed.

in 2013 results alpha magnetic spectrometer on international space station indicated excess high-energy cosmic rays due dark matter annihilation.