# The Galaxy Stellar Mass Function and Low Surface Brightness Galaxies from Core-Collapse Supernovae

## TL;DR

This paper presents a novel method using core-collapse supernovae to identify low surface brightness galaxies, enabling an unbiased measurement of the star-forming galaxy stellar mass function down to very low masses.

## Contribution

It introduces a supernova-based selection method for galaxies, uncovers new low surface brightness galaxies, and develops a new photometric redshift code for small galaxy samples.

## Key findings

- Number densities follow a Schechter function with a faint-end slope of -1.41.
- Detected approximately 150 previously unidentified low surface brightness galaxies.
- Results align with EAGLE simulation predictions under a DM cosmology.

## Abstract

We introduce a method for producing a galaxy sample unbiased by surface brightness and stellar mass, by selecting star-forming galaxies via the positions of core-collapse supernovae (CCSNe). Whilst matching $\sim$2400 supernovae from the SDSS-II Supernova Survey to their host galaxies using IAC Stripe 82 legacy coadded imaging, we find $\sim$150 previously unidentified low surface brightness galaxies (LSBGs). Using a sub-sample of $\sim$900 CCSNe, we infer CCSN-rate and star-formation rate densities as a function of galaxy stellar mass, and the star-forming galaxy stellar mass function. Resultant star-forming galaxy number densities are found to increase following a power-law down to our low mass limit of $\sim10^{6.4}$ M$_{\odot}$ by a single Schechter function with a faint-end slope of $\alpha = -1.41$. Number densities are consistent with those found by the EAGLE simulations invoking a $\Lambda$-CDM cosmology. Overcoming surface brightness and stellar mass biases is important for assessment of the sub-structure problem. In order to estimate galaxy stellar masses, a new code for the calculation of galaxy photometric redshifts, zMedIC, is also presented, and shown to be particularly useful for small samples of galaxies.