***********************************************************
OATS-DAUT SEMINAR
***********************************************************
Speaker:
Luigina Feretti (INAF/Istituto di Radioastronomia, BO)
Title:
Radio emission in clusters of galaxies
Date: Wednesday, September 20th, 2006
Time: 12:00 noon
Venue: Villa Bazzoni
***********************************************************
Abstract: An important component of the intracluster medium
in galaxy clusters is represented by a population of relativistic
particles, which interact with large-scale magnetic fields producing
diffuse synchrotron emission detected at radio wavelengths. Diffuse
radio sources of the order of Mpc in size have been detected in
clusters both in central regions (halos) and in peripheral regions
(relics). Observational results provide evidence that these phenomena
are connected to the structure formation process: indeed a cluster
merger activity is likely to supply the energy for the maintenance of
halos and relics. I will present recent results on the spectral index
distibution of radio halos, showing a strict connection to the cluster
merger, and I will briefly outline the mechanisms responsible for the
energy transfer from cluster mergers to the radio emitting particles.
***********************************************************