NGC 147 Corroborates the Break in the Stellar Mass–Stellar Metallicity Relation for Galaxies

The stellar mass–stellar metallicity relation (MZR) is an essential approach to probing the chemical evolution of galaxies. It reflects balance between galactic feedback and gravitational potential as a function mass. However, current MZR local dwarf satellite galaxies (M* ? 108 M?; measured from resolved spectroscopy) may not be reconcilable with that more massive ? 109.5 integrated-light spectroscopy). Such discrepancy result systematic difference two methods, or it indicate break in around 109 M?. To address this question, we NGC 147 integrated light using Palomar Cosmic Web Imager. We compared estimates measurements spectroscopy found them consistent within 0.1 dex. On other hand, high-mass overpredicts by 0.6 dex at mass 147. Therefore, our results tentatively suggest low-mass should attributed techniques. Instead, real physical processes cause transition MZR. In addition, discovered positive age gradient innermost region negative stars larger radii, suggesting possible outside-in formation