In this short note we have reconsidered the Jeans criterion for gravitational contraction of a gas nebula at different temperatures, from the present-day background radiation temperature (2.8 K) to those which existed at the early stage of the Universe. We demonstrate that the initial mass of quasars cannot be of the order of single galaxy masses, but rather 10⁶ solar mass only. If they have larger masses, it must be the result of subsequent accretion process. Nevertheless quasars, formed prior to the stars, were the immediate source of the elements heavier than helium.

Stars; Quasars; Background Radiation; Jeans Criterion; Gravitational Contraction; Nebulae

S. Halas and T. Durakiewicz, "Why Do the Main Sequence Stars Have Similar Chemical Composition?," International Journal of Astronomy and Astrophysics, Vol. 2 No. 1, 2012, pp. 37-38. doi: 10.4236/ijaa.2012.21006.