Abstract

High-redshift galaxies are often characterized by extreme emission line properties potentially indicating that the ISM properties of galaxies at z>6 are different from what they are in the local Universe. For this reason, local Green Pea and Blueberry galaxies are often used as laboratories to study high-redshift galaxy formation due to their similarly extreme observational properties. In this talk, I will introduce the SPHINX -20 simulations and discuss the use of various strong-line diagnostics and emission line ratios (such and [OIII]/[CII] and the [MgII] doublet ratio) for constraining ISM and galaxy properties such as gas density, metallicity, star formation rate and Lyman continuum escape fraction. I will compare how well these diagnostics work on low-redshift analogues with simulated galaxies in the epoch of reionization.