The physics of electron re-acceleration in galaxy clusters and the dependence of the selected cluster population on wavelength

Data: 
17/03/2021 - 14:00 - 15:00
Local: 
Remoto, com transmissão pela internet
 
 
The physics of electron re-acceleration in galaxy clusters and the dependence of the selected cluster population on wavelength
 
Felipe Andrade-Santos
 
CfA-Harvard
 
On the largest scales, the Universe consists of voids and filaments making up the cosmic web. Galaxy clusters are located at the knots in this web, at the intersection of filaments. Clusters grow through accretion from these large-scale filaments and by mergers with other clusters and groups. In a growing number of galaxy clusters, elongated Mpc-sized radio sources have been found. Also known as radio relics, these regions of diffuse radio emission are thought to trace relativistic electrons in the intracluster plasma accelerated by low-Mach-number shocks generated by cluster-cluster merger events. A long-standing problem is how low-Mach-number shocks can accelerate electrons so efficiently to explain the observed radio relics. In this talk, I will present an exciting discovery about radio relics made by combining radio, X-ray, and optical observations of the merging galaxy cluster Abell 3411-3412. I will also present a comparison of the fraction of cool-core clusters in the Planck early Sunyaev-Zel’dovich (ESZ) sample of detected clusters and in a flux-limited X-ray sample.
 
 
Felipe Andrade-Santos is the Director of the Clay Center Observatory at Dexter Southfield, and a Research Associate at the Center for Astrophysics / Harvard & Smithsonian. His primary research interest is galaxy clusters, more specifically measuring their masses, using them for cosmological studies, and particle re-acceleration at galaxy cluster shocks.