What does the IMF really tell us about star formation?

TL;DR

This paper argues that the initial mass function (IMF) alone cannot reveal the true star formation process, emphasizing the importance of understanding primordial binary populations for accurate insights.

Contribution

It demonstrates that different star formation modes can produce identical IMFs, highlighting the need to study binary star properties to understand star formation.

Findings

IMF alone cannot distinguish star formation modes

Binary population properties are crucial for understanding star formation

Different formation processes can yield similar IMFs

Abstract

Obtaining accurate measurements of the initial mass function (IMF) is often considered to be the key to understanding star formation, and a universal IMF is often assumed to imply a universal star formation process. Here, we illustrate that different modes of star formation can result in the same IMF, and that, in order to truly understand star formation, a deeper understanding of the primordial binary population is necessary. Detailed knowledge on the binary fraction, mass ratio distribution, and other binary parameters, as a function of mass, is a requirement for recovering the star formation process from stellar population measurements.