Speaker
Mr
Stephan Zimmer
(CoPS, Fermi-LAT)
Description
Clusters of Galaxies are the largest virialized structures in the universe. Radio
observations indicate the presence of a relativisitic electron population that can
give rise to a distinct gamma-ray signature through scattering with low energy
photons. In addition, gamma-rays can result from collisions of cosmic ray protons
with particles in the intracluster medium through subsequent $\pi^0$ decay.
Moreover, clusters of galaxies possess high mass-to-light ratios, making them
interesting targets for indirect dark matter searches. In this case, gamma rays
may be produced from the decay or annihilation of dark matter particles. The
predicted gamma-ray spectra for clusters of galaxies is distinct from the diffuse
galactic and extragalactic background emission making them an exciting
potential source class for the Fermi-LAT. The spectral characteristics of dark
matter annihilation or decay and of cosmic ray emission are expected to be
universal in different clusters, making a combined statistical treatment feasible.
We present a combined likelihood analysis and set limits on the Dark Matter
annihilation cross section or decay time and on the hadron injection efficiency.
Primary author
Mr
Stephan Zimmer
(CoPS, Fermi-LAT)
