The emergence of the galactic stellar mass function from a non-universal IMF in clusters

TL;DR

This paper explores how variations in the initial stellar mass functions of clusters influence the overall galactic stellar mass function, revealing that cluster-to-cluster differences can produce a multicomponent galactic mass distribution consistent with observations.

Contribution

It demonstrates that non-universal IMFs in clusters lead to a multicomponent galactic stellar mass function that aligns with observed data, highlighting the impact of cluster IMF variations.

Findings

Cluster IMF variations produce a multicomponent galactic mass function.

A dispersion of ~0.3 M$_{ ext{sun}}$ in IMF characteristic mass matches observed galactic mass function.

Low mass slope of the galactic mass function aligns with observations despite steep individual cluster IMFs.

Abstract

We investigate how a single generation galactic mass function (SGMF) depends on the existence of variations in the initial stellar mass functions (IMF) of stellar clusters. We show that cluster-to-cluster variations of the IMF lead to a multicomponent SGMF where each component in a given mass range can be described by a distinct power-law function. We also show that a dispersion of $\approx 0.3$ M$_{\odot}$ in the characteristic mass of the IMF, as observed for young Galactic clusters, leads to a low mass slope of the SGMF that matches the observed Galactic stellar mass function even when the IMFs in the low mass end of individual clusters are much steeper.