From Haloes to Galaxies. III. The Gas Cycle of Local Galaxy Populations

In Dou et al., we introduced the fundamental formation relation (FFR), a tight between specific star rate (sSFR), H2 efficiency (SFE), and ratio of to stellar mass. Here, show that atomic gas H ? does not follow similar FFR as H2. The SFEH? sSFR shows significant scatter strong systematic dependence on all key galaxy properties have explored. dramatic difference indicates different processes (e.g., quenching by mechanisms) may very effects in galaxies hence produce SFEH?–sSFR relations, while SFE–sSFR remains unaffected. fact is independent other properties, directly related cosmic time acts clock, make it natural simple study how populations (with undergoing processes) evolve same ? t relation. regulator model (GRM), evolution SFE–sSFR(t) uniquely set single mass-loading parameter . This simplicity allows us accurately derive supply removal rates local with masses, from star-forming process being quenched. combination GRM, together metallicity requirement, provide new powerful tool evolution.