Redshift evolution of the H2/H <scp>i</scp> mass ratio in galaxies

In this paper we present an attempt to estimate the redshift evolution of molecular neutral gas mass ratio within galaxies (at fixed stellar mass). For a sample five nearby grand design spirals located on Main Sequence (MS) star forming galaxies, exploit maps at 500 pc resolution and formation rate ($M_{\star}$ SFR). same cells, also have estimates ($M_{\rm HI}$) H_2}$) masses. To compute two relations: {\it i)} one between molecular-to-neutral total gas}$), whose scatter shows strong dependence with distance from spatially resolved MS, ii)} $\log(M_{\rm{H_2}}/M_{\star})$ $\log(M_{\rm{HI}}/M_{\star})$. both methods, find that $M_{\rm H_2}$/$M_{\rm HI}$ optical radius slightly decreases redshift, contrary common expectations becoming progressively more dominated by hydrogen high redshifts. We discuss possible implications trend our understanding internal working galaxies.