Initial mass function

The original mass function, also Initial Mass Function, English Initial Mass Function IMF, describes how, in a newly formed stellar population looks like the distribution of stellar masses.

Edwin Salpeter introduced first time in 1955 the initial mass function for the solar neighborhood and was a hit for stars between about 0.4 and 10 solar masses a relationship

With exponent before, where dN is the number of stars per unit volume with a mass between M and M dM. In this nitric function so massive stars are much less likely than low-mass.

If this relationship continues to very small masses down, then the total stellar mass of very low-mass stars would dominate. Current provisions of the initial mass function, however, indicate a flattening of this relationship below 0.5 solar masses. The universality of the initial mass function seems to collapse below 0.1 solar masses. In this area, the IMF varies between star-forming regions and the difference is not the result of dynamic interactions that accelerate the lighter star from these regions out.

The explanation of the initial mass function is an important task for models of star formation, especially since it seems to vary little between different star-forming regions.