Sunyaev-Zeldovich effect: Shadows in the Cosmic Radiation

Abstract

Soon after the discovery of the cosmic background radiation, Zeldovich and Sunyaev proposed that hot gas in galaxy clusters should cast a faint shadow because of the interaction between energetic electrons and the radiation photons. Sunayev-Zeldovich effect is now routinely observed, and it has become an important tool for studying the history of the universe.