The fundamental plane of star formation in galaxies revealed by the EAGLE hydrodynamical simulations

Understand

We investigate correlations between different physical properties of star-forming galaxies in the "Evolution and Assembly of GaLaxies and their Environments" (EAGLE) cosmological hydrodynamical simulation suite over the redshift range $0\le z\le 4.5$.

• A principal component analysis reveals that neutral gas fraction ($f_{\rm gas, neutral}$), stellar mass ($M_{\rm stellar}$) and star formation rate (SFR) account for most of the variance seen in the population, with galaxies tracing a two-dimensional, nearly flat, surface in the three-dimensional space of $f_{\rm gas, neutral}-M_{\rm stellar}-\rm SFR$ with little scatter.
• The location of this plane varies little with redshift, whereas galaxies themselves move along the plane as their $f_{\rm gas, neutral}$ and SFR drop with redshift.
• The positions of galaxies along the plane are highly correlated with gas metallicity.