# Modelling the outskirts of galaxies in a cosmological context

## TL;DR

This paper discusses how discrepancies between cosmological simulations and observed galaxy properties, especially for less massive galaxies, may stem from how well models match the observed galaxy stellar mass function.

## Contribution

It highlights the importance of the galaxy stellar mass function in understanding discrepancies in galaxy outskirts modeling within cosmological simulations.

## Key findings

- Simulations broadly match observed surface brightness trends.
- Discrepancies are more pronounced in less massive galaxies.
- Matching the stellar mass function is crucial for accurate modeling.

## Abstract

Current data broadly support trends of galaxy surface brightness profile amplitude and shape with total stellar mass predicted by state-of-the-art Lambda-CDM cosmological simulations, although recent results show signs of interesting discrepancies, particularly for galaxies less massive than the Milky Way. Here I discuss how perhaps the largest contribution to such discrepancies can be inferred almost directly from how well a given model agrees with the observed present-day galaxy stellar mass function.