SCYON Abstract

Received on August 22 2003

Field-IMFs of Massive Stars

AuthorsPavel Kroupa, Carsten Weidner
University of Kiel, Germany
Accepted byAstrophysical Journal


Over the past years observations of young and populous star clusters have shown that the stellar IMF appears to be an invariant featureless Salpeter power-law with an exponent alpha=2.35 for stars more massive than a few solar masses. A consensus has also emerged that most, if not all, stars form in stellar groups and star clusters, and that the mass function of young star clusters in the solar-neighborhood and in interacting galaxies can be described, over the mass range of a few 10 Mo to 10^7 Mo, as a power-law with an exponent ß ~2. These two results imply that galactic-field IMFs for early-type stars cannot, under any circumstances, be a Salpeter power-law, but that they must have a steeper exponent alpha(field) ~> 2.8. This has important consequences for the distribution of stellar remnants and for the chemo-dynamical and photometric evolution of galaxies.