Date/Time
Date(s) - 25/11/2009
3:20 pm - 4:20 pm

Title: High-Energy Phenomena and Dark Matter Searches in Galaxy Clusters

Speaker: Dr. Christoph Pfommer – CITA

Institute: CITA

Location: ABB 102

Description:

In the last years, gamma-ray astronomy has transformed into an exciting and vibrating field that tremendously improved our knowledge about the galactic gamma-ray sky and associated high-energy processes. The next milestone will be the first detection of gamma-rays from galaxy clusters by the Fermi gamma-ray space telescope as well as the next generation of imaging air Cerenkov telescopes. Clusters of galaxies are expected to contain significant populations of cosmic ray electrons and protons originating from different sources, such as structure formation shocks and active galactic nuclei which are thought to emit high energy gamma-rays. At the same time, nearby galaxy clusters are one of the prime targets for detecting the annihilation signal of dark matter as they constitute the most massive objects in our Universe that are forming today. I will review what clusters told us in the past about the properties of dark matter. I will then introduce the individual aspects of high-energy radiative processes and dark matter annihilation in the context of the exciting new results from PAMELA, Fermi, and HESS that recently attained much attention. I will close the talk by discussing which surprising insight we could gain from these results not only into the particle physics nature of dark matter but also into one of the pillars of our standard model of cosmological structure formation.