# The Varying Mass Distribution of Molecular Clouds Across M83

## TL;DR

This study analyzes molecular cloud populations in galaxy M83 using ALMA data, revealing a radial decrease in maximum cloud mass similar to young cluster mass trends, with internal cloud conditions remaining constant across the galaxy.

## Contribution

It provides the first detailed analysis of molecular cloud mass distribution in M83, demonstrating a radial variation in maximum cloud mass and linking it to cluster formation.

## Key findings

- Maximum molecular cloud mass decreases with galactocentric radius.
- No significant variation in internal cloud conditions across the galaxy.
- Most massive young clusters are proportional to the most massive clouds.

## Abstract

The work of Adamo et al. (2015) showed that the mass distributions of young massive stellar clusters were truncated above a maximum-mass scale in the nearby galaxy M83 and that this truncation mass varies with galactocentric radius. Here, we present a cloud-based analysis of ALMA CO($1\to 0$) observations of M83 to search for such a truncation mass in the molecular cloud population. We identify a population of 873 molecular clouds in M83 that is largely similar to those found in the Milky Way and Local Group galaxies, though clouds in the centre of the galaxy show high surface densities and enhanced turbulence, as is common for clouds in high-density nuclear environments. Like the young massive clusters, we find a maximum-mass scale for the molecular clouds that decreases radially in the galaxy. We find the most massive young massive cluster tracks the most massive molecular cloud with the cluster mass being $10^{-2}$ times that of the most massive molecular cloud. Outside the nuclear region of M83 ($R_{g}>0.5$ kpc), there is no evidence for changing internal conditions in the population of molecular clouds, with the average internal pressures, densities, and free-fall times remaining constant for the cloud population over the galaxy. This result is consistent with the bound cluster formation efficiency depending only on the large-scale properties of the ISM, rather than the internal conditions of individual clouds.