Exploring Dark Matter with Milky Way Substructure
Michael Kuhlen,1,*
Piero Madau,2
Joseph Silk3
The unambiguous detection of dark matter annihilation in our
Galaxy would unravel one of the most outstanding puzzles in
particle physics and cosmology. Recent observations have motivated
models in which the annihilation rate is boosted by the Sommerfeld
effect, a nonperturbative enhancement arising from a long-range
attractive force. We applied the Sommerfeld correction to Via
Lactea II, a high-resolution
N-body simulation of a Milky Way–sized
galaxy, to investigate the phase-space structure of the galactic
halo. We found that the annihilation luminosity from kinematically
cold substructure could be enhanced by orders of magnitude relative
to previous calculations, leading to the prediction of gamma-ray
fluxes from as many as several hundred dark clumps that should
be detectable by the Fermi satellite.
2 Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA.
3 Department of Physics, University of Oxford, Oxford OX1 3RH, UK.
* To whom correspondence should be addressed. E-mail: mqk{at}ias.edu
