Dwarf spheroidal galaxies as targets for indirect dark matter searches

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Dwarf spheroidal galaxies as targets for indirect
dark matter searches

• Ewa L. Lokas
• (Copernicus Center, Warsaw)

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Indirect dark matter searches

• Gamma rays predicted as annihilation products of
  SUSY dark matter
• Imaging Atmospheric Cherenkov Telescope (IACT)
  arrays HESS, VERITAS, MAGIC, CACTUS
• Satellites GLAST (planned for 2007)

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Targets for dark matter searches

• Milky Way (galactic centre, substructure)
• Very near so flux should be high, but crowded
• Andromeda
• galaxy clusters
• dwarf spheroidal galaxies

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Dwarf spheroidal galaxies

• They are believed to be strongly dark matter
  dominated with M/L gt 100 M?/L?
• Few of them are within 100 kpc
• Their masses and mass distributions are important
  for the solution of the overabundance problem and
  the cusp/core problem
• They are perfect targets for indirect dark matter
  searches

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Draco dwarf
Wellstudied dwarf at 80 kpc with high M/L gt 100
M?/L?
Local Group
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Stellar kinematics in Draco
Velocity moments
Dark matter distribution estimated by modelling
velocity distribution from kinematic data for 207
stars
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Dark matter distribution in Draco
Dark matter distribution model based on Nbody
simulations of tidal stripping of dwarfs in the
Milky Way potential
a1 (cusp) a0 (core) Mtot
5.5 108M? 1.2 108M?
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CACTUS ?ray excess from Draco
Profumo Kamionkowski (2006)