A new SPHINX paper titled “Mg II in the JWST Era: a Probe of Lyman Continuum Escape?” by Katz et al. has been accepted for publication in MNRAS. The authors use SPHINX to probe whether there exists a correlation between the escape of ionizing radiation from galaxies and their MgII emission and absorption. If it exists, such a correlation could be used to identify the galaxies that power reionization. Statistically there is a tendency for galaxies with high LyC escape fractions to be MgII emitters, but with a lot of scatter. In short it’s complicated and line emission is difficult to interpret, especially since the same galaxy can exhibit very different spectral properties along different lines of sight.