Download - Karl Mannheim – ITPA Würzburg
Karl Mannheim – ITPA Würzburg
Gamma rays from the Virgo and Gamma rays from the Virgo and Coma clusters of galaxiesComa clusters of galaxies
Berlin CTA-Meeting, May 4-5, 2006Berlin CTA-Meeting, May 4-5, 2006
Clusters of Galaxies
• Storage of (UHE) cosmic rays– Supernova-driven winds– Radiojets from Active Galactic Nuclei
• Acceleration of (UHE) cosmic rays– Cluster merger shocks– Accretion shocks– Dynamical relaxation shocks
• Dark matter annihilation – Largest mass concentrations– Small-scale clumps dominance: Sorting in
dM/R2
» Galactic Center» Nearest halo clump (unidentified EGRET?)» Nearest rich clusters (Virgo, Coma, Perseus)» Nearest dwarf galaxies (Sagittarius, Draco)
Galactic Vicinity (200 kpc)
Local Group (2 Mpc)
Local Universe (60 Mpc)
Local Universe (300 Mpc)
Virgo cluster
Coma cluster
Cosmic rays in nearby clusters of galaxies
Pfrommer et al.: Cosmic ray propagation model fitted to radio and X-ray observations, employing hydrodynamical code for of intracluster medium (-ray fluxes > 50 GeV)
Cosmic rays in Coma
Berrington & Dermer:
Cluster merger shock
Völk et al.: Cosmic ray propagation
Reimer et al. Cosmic ray propagation
M 87 / Virgo Cluster
C=40
C=335
Targeted observations seem promising with new – generation experiments
DarkSusy scan
Control astrophysical backgrounds:-AGN in M87-CRp – interactions-MAGIC observations have started in May 2005
M87 SED
(ICRC)
Structure Formation• ART Code (A. Klypin et al.)
• 3 £ 1014 solar masses; 9 million particles („Virgo Cluster“)
• (sub)structure down to 3 £ 107 solar masses: clumps!
D. Elsaesser, S. Gottloeber, A. Khalathyan and M. Steinmetz
2DM ds
Summary
Clusters are cutting-edge targets for current IACTsRich potential for astrophysics, cosmology, and
particle physics
Origin of UHE cosmic rays Dark matter annihilation Role of nonthermal plasma in structure
formation
… northern location prefered for a dedicated„cluster mission“with future CTAs…