Dependence of the ratio of total to visible mass on observable properties of SDSS MaNGA galaxies

TL;DR

This study analyzes how the ratio of total to visible mass in SDSS MaNGA galaxies correlates with properties like luminosity, metallicity, and environment, revealing distinct trends among different galaxy types and proposing a predictive parametrization.

Contribution

It introduces a statistical model to estimate galaxy mass ratios and explores their dependence on observable properties, providing new insights into galaxy evolution and a predictive tool.

Findings

Faint, low-metallicity galaxies have the highest mass ratios.

Bright, high-metallicity galaxies in the red sequence have elevated mass ratios.

A parametrization is developed to predict mass ratios from photometry and luminosity.

Abstract

Using spectroscopic observations from the SDSS MaNGA DR15, we study the relationships between the ratio of total to visible mass and various parameters characterizing the evolution and environment of the galaxies in this survey. Measuring the rotation curve with the relative velocities of the H-alpha emission line across the galaxy's surface, we estimate each galaxy's total mass. We develop a statistical model to describe the observed distribution in the ratio of total to visible mass, from which we extract a galaxy's most probable value for this mass ratio. We present the relationships between the ratio of total to visible mass and several characteristics describing galactic evolution, such as luminosity, gas-phase metallicity, distance to the nearest neighbor, and position on the color-magnitude diagram. We find that faint galaxies with low metallicities, typically in the blue cloud, have the highest ratios of total to visible mass. Those galaxies that exhibit the second highest ratios of total to visible mass are the brightest with high metallicities, typically members of the red sequence or green valley. AGN activity is likely both the quenching mechanism and the feedback that drives the mass ratio higher in these massive galaxies. Finally, we introduce a parametrization that predicts a galaxy's ratio of total to visible mass based on its photometry and luminosity.