Unavoidable spectral distortions of the Cosmic Background Radiation
There is a question how and at which redshifts the observed practically ideal black body spectrum of Cosmic Microwave Background Radiation was formed. I plan to describe the nature of the black body photosphere of the Universe and to discuss in detail the unavoidable spectral distortions of CMB due to cosmological recombination, Silk damping and presence of the hot gas in the early Universe. It will be mentioned why we will never observe in the spectrum of CMB the traces of electron-positron annihilation in the early Universe or due to decay of tritium and Be to Li conversion at z ~ 30 000.
Rashid Sunyaev was born in Tashkent, Uzbekistan, and educated at the Moscow Institute of Physics and Technology and Moscow University. The head of the High Energy Astrophysics Department of the Russian Academy of Sciences from 1982 to 2002 and chief scientist of the Academy’s Space Research Institute since 1992, he holds several concurrent positions, including editor-in-chief of Astronomy Letters. He currently divides his time between Moscow and Garching, Germany, where he is managing director of the Max Planck Institute for Astrophysics. He worked for several years with his teacher, Yakov B. Zel’dovich, in the Moscow Institute of Applied Mathematics, where the two proposed what is known as the Sunyaev-Zel’dovich effect, an important method for determining absolute distances and hence the Hubble constant from the effect of gas in galaxy clusters on the cosmic microwave background radiation. Sunyaev and N. Shakura developed a model of disk accretion onto black holes, and he has proposed a signature for X-radiation from matter spiraling into a black hole. He has collaborated in important studies of the early universe, including the recombination of hydrogen and the formation of the cosmic microwave background radiation.