# The [CII]--SFR correlation in dwarf galaxies across cosmic time

## TL;DR

This study uses high-resolution simulations to explore how the [CII] emission and star formation rate correlation in dwarf galaxies depends on metallicity, revealing an evolution that is difficult to observe due to large scatter.

## Contribution

It provides the first detailed simulation-based analysis of the metallicity dependence of the [CII]-SFR correlation in dwarf galaxies, incorporating self-consistent metal evolution.

## Key findings

- The [CII]-SFR correlation evolves with metallicity, aligning with theoretical models.
- Large observational scatter makes this evolution hard to detect.
- Most [CII] emission originates from neutral, low-density gas, with densest regions near star formation sites.

## Abstract

Current galaxy observations suggest that a roughly linear correlation exists between the [CII] emission and the star formation rate, either as spatially-resolved or integrated quantities. Observationally, this correlation seems to be independent of metallicity, but the very large scatter does not allow to properly assess whether this is true. On the other hand, theoretical models tend to suggest a metallicity dependence of the correlation. In this study, we investigate the metallicity evolution of the correlation via a high-resolution zoom-in cosmological simulation of a dwarf galaxy employing state-of-the-art sub-grid modelling for gas cooling, star formation, and stellar feedback, and that self-consistently evolves the abundances of metal elements out of equilibrium. Our results suggest that the correlation should evolve with metallicity, in agreement with theoretical predictions, but also that this evolution can be hardly detected in observations, because of the large scatter. We also find that most of the [CII] emission is associated with neutral gas at low-intermediate densities, whereas the highest emissivity is produced by the densest regions around star-forming regions.