Astrophysics (index)

Initial Mass Function

(function describing initial mass of stars)

The Initial Mass Function (IMF) is an empirical density/mass-style function that describes the distribution of initial masses of stars. It is typically given as N(m)dm.

  • m - mass of a star.
  • N(m) - number of stars at that mass.

Edwin Salpeter developed an early IMF in 1955, the Salpeter function:

N(m)dm = C × (m/MSun)-2.35(dm/MSun)

C is a constant reflecting local stellar density.

The IMF can be derived from the Luminosity Function and the Mass-Luminosity Relation.


Referenced by:
Dense Core Mass Function (DCMF)
Power Law
Stellar Population Synthesis Code