Physics Colloquium : "Collisionless shocks around the largest structures"

Date: 
Mon, 18/03/202412:00-13:30
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Location: 
Levin building, Lecture Hall No. 8
Lecturer: 
Prof. Uri Keshet (BGU)

Pristine collisionless shocks were recently detected around galaxy clusters: island universes feeding at the cosmic-web nodes, the largest objects ever to virialize. Although collisionless shocks were anticipated in the 1950s, a self-consistent model for these natural particle accelerators, which boost charged particles to ultra-relativistic cosmic rays, is still unavailable. Galaxy-cluster observations regularly challenge theory, with no self-consistent models for their structure, apparent cooling stability, and unexpected spiral dynamics. Challenges and new hints pertaining to both collisionless-shock and galaxy-cluster physics will be outlined.