Kamlesh RAJPUROHIT (CfA, Harvard; Università di Bologna; INAF, Institute of Radio Astronomy), who will talk about “Abell 746: A highly disturbed cluster undergoing multiple mergers“.
You can find the schedule of upcoming café-clubs and the video of old ones at http://wiki.lam.fr/geco/CafeClub .
Take care,
Carlo, Meriam, Paolo
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ABSTRACT
Merging galaxy clusters host Mpc-scale diffuse radio sources known as radio relics and radio halos. With their enormous extent, these sources trace the largest particle accelerators in the Universe. Relics are illuminated by relativistic electrons accelerated at shock fronts while radio halos are believed to be formed by merger-induced turbulence. However, the currently proposed particle acceleration mechanisms are not efficient enough to accelerate particles from the thermal pool of the intracluster medium (ICM). In this talk, I will present deep XMM-Newton and radio observations of the merging galaxy Abell 746 which hosts a plethora of diffuse emission sources that provide evidence for the acceleration of relativistic particles. Our new images reveal a complex morphology of the ICM with multiple substructures and an asymmetric temperature distribution. We found evidence of four X-ray edges, of which three are merger-driven shock fronts. Our findings suggest that Abell 746 is a complex system that involves multiple mergers.