New Insights into Stellar Metallicities in Galaxies

Recent research has uncovered significant differences in how stellar metallicities are regulated in star-forming and quiescent galaxies. The study, titled "Different regulation of stellar metallicities between star-forming and quiescent galaxies -- Insights into galaxy quenching," was conducted by William M. Baker and eight co-authors. It addresses a critical question in astrophysics: what causes galaxies to cease star formation?

The authors found that for star-forming galaxies, stellar metallicity is primarily influenced by stellar mass. In contrast, for quiescent galaxies, stellar metallicity is more closely linked to stellar velocity dispersion, which is correlated with black hole mass. This connection suggests that the feedback from black holes may play a crucial role in the quenching process of galaxies.

The research utilized a large sample of galaxies to analyze these relationships, revealing that the cessation of star formation, often referred to as 'quiescence,' is associated with two primary factors: the mass of the black hole and the halting of gas inflows, termed 'starvation.' As gas inflows stop, the remaining gas is consumed by star formation, leading to rapid chemical enrichment of the galaxy.

These findings provide a clearer understanding of the mechanisms behind galaxy quenching and highlight the importance of black hole feedback in regulating star formation. The implications of this research extend to our understanding of galaxy evolution and the lifecycle of galaxies in the universe. The paper is available for further reading at arXiv:2309.00670.