The Initial Mass Spectra of Astronomical Objects

Resumo

The fundamental premises concerning the existence of a universal basic distribution describing the initial mass functions (IMFs) of various astronomical objects on scales from brown dwarfs to clusters of galaxies are considered. This distribution has the form dN ∝ M⁻²dM, where M is the mass of an object and N the number of objects with a given mass. It is shown that, at least for objects forming as a result of fragmentation (e.g., stars, star clusters), the basis of this distribution may correspond to a white-noise model. The classical problem of the formation of the IMF for stars is discussed in this context, incuding the relationship between the mass function of protostellar clouds and the stellar IMF. The main factors determining the mass functions of galaxies and galaxy clusters are also considered.