The 2012 Benjamin Franklin Medal in Physics presented to Rashid Sunyaev

The work of Rashid Sunyaev and collaborators is summarized in three specific areas in which he has made monumental contributions to astrophysics and cosmology. Sunyaev and Zel'dovich developed the theory for the evolution of density fluctuations in the early universe. They predicted the pattern of acoustic fluctuations that have been clearly seen by WMAP and other CMB experiments in the microwave sky and in the large-scale distribution of galaxies. Sunyaev, Zeldovich [9] showed that the strong X-ray emission and coincident “holes” at radio wavelengths were due to cosmic microwave photons undergoing inverse Compton scattering with relativistic electrons in the intra-cluster gas, thus gaining enough energy for the photons to be at X-ray wavelengths. The Sunyaev-Zel'dovich effect has been applied to determine fundamental cosmological parameters, including direct measurements of the Hubble constant, and to probe exotic puzzles in cosmology such as the nature of dark energy. The Shakura and Sunyaev theory of disk accretion has been applied to understand accretion flows across a broad range of astrophysical domains from supermassive black holes, the central engines at the centers of quasars and active galactic nuclei, to stellar mass black holes, neutron stars and white dwarfs in close binaries. Their theory remains the standard paradigm for the theory of accretion disks and accretion by black holes. Biographical information and past awards of the greatest distinction are summarized.