Dimensional argument for the impact of turbulent support on the stellar initial mass function

TL;DR

This paper presents a simple dimensional argument showing how turbulent support influences the shape of the prestellar core mass function, crucial for understanding the stellar initial mass function, especially its high-mass slope.

Contribution

It introduces a straightforward dimensional approach to demonstrate the role of turbulent support in shaping the IMF, confirming results from the Hennebelle-Chabrier theory.

Findings

Turbulent support is essential to reproduce the Salpeter slope in the high-mass IMF.

Pure thermal support results in a steeper high-mass slope.

The dimensional argument aligns with detailed theoretical models.

Abstract

We present a simple dimensional argument to illustrate the impact of nonthermal support from turbulent velocity dispersion on the shape of the prestellar core mass function (CMF), precursor of the stellar initial mass function (IMF). The argument demonstrates the need to invoke such support to recover the Salpeter slope in the high-mass part of the CMF/IMF, whereas pure thermal support leads to a much steeper slope. This simple dimensional argument clearly highlights the results obtained in the complete Hennebelle-Chabrier theory of the IMF.