MaNGA DynPop -- II. Global stellar population, gradients, and star-formation histories from integral-field spectroscopy of 10K galaxies: link with galaxy rotation, shape, and total-density gradients

TL;DR

This study analyzes the stellar populations, gradients, and star-formation histories of about 10,000 galaxies from the MaNGA survey, revealing correlations with galaxy dynamics, rotation, and mass density, and providing a public catalog.

Contribution

It offers new insights into how stellar population properties relate to galaxy rotation, shape, and density gradients, expanding understanding of galaxy evolution.

Findings

Younger galaxies are more metal-poor at fixed velocity dispersion.

Stellar age, metallicity, and M*/L decrease with increasing galaxy rotation.

Massive disk galaxies show steep gradients and signs of recent star formation.

Abstract

This is the second paper of the MaNGA DynPop series, which analyzes the global stellar population, radial gradients, and non-parametric star-formation history of $\sim 10$K galaxies from the MaNGA Survey final data release 17 (DR17) and relates them with dynamical properties of galaxies. We confirm the correlation between the stellar population properties and the stellar velocity dispersion $\sigma_{\rm e}$, but also find that younger galaxies are more metal-poor at fixed $\sigma_{\rm e}$. Stellar age, metallicity, and mass-to-light ratio $M_{\ast}/L$ all decrease with increasing galaxy rotation, while their radial gradients become more negative (i.e. lower value at the outskirts). The exception is the slow rotators, which also appear to have significantly negative metallicity gradients, confirming the mass-metallicity gradient correlation. Massive disk galaxies in the green valley, on the $(\sigma_{\rm e},\rm Age)$ plane, show the most negative age and metallicity gradients, consistent with their old central bulges surrounded by young star-forming disks and metal-poor gas accretion. Galaxies with high $\sigma_{\rm e}$, steep total mass-density slope, low dark matter fraction, high $M_{\ast}/L$, and high metallicity have the highest star-formation rate at earlier times, and are currently quenched. We also discover a population of low-mass star-forming galaxies with low rotation but physically distinct from the massive slow rotators. A catalogue of these stellar population properties is provided publicly.