EDGE: Predictable Scatter in the Stellar Mass--Halo Mass Relation of Dwarf Galaxies

Understand

The stellar-mass--halo-mass (SMHM) relation is central to our understanding of galaxy formation and the nature of dark matter.

• However, its normalisation, slope, and scatter are highly uncertain at dwarf galaxy scales.
• In this paper, we present DarkLight, a new semi-empirical dwarf galaxy formation model designed to robustly predict the SMHM relation for the smallest galaxies.
• DarkLight harnesses a correlation between the mean star formation rate of dwarfs and their peak rotation speed -- the $\langle$SFR$\rangle$-$v_{\rm max}$ relation -- that we derive from simulations and observations.