SDSS-IV MANGA: A Star Formation -- Baryonic Mass Relation at Kpc Scales

TL;DR

This study establishes a strong empirical relation between star formation rate density and baryonic mass surface density at kpc scales using MaNGA survey data, highlighting the combined influence of stellar and molecular gas mass.

Contribution

It introduces a new empirical relation linking $ m ext{SFR}$ density with baryonic mass surface density, incorporating both stellar and molecular gas components, derived from spatially-resolved galaxy data.

Findings

$ m ext{SFR}$ density correlates tightly with baryonic mass surface density.

A second degree polynomial relation fits $ m ext{SFR}$ density and baryonic mass surface density.

The combined baryonic mass components show a stronger correlation with star formation activity.

Abstract

Star formation rate density, $\Sigma_{\rm SFR}$, has shown a remarkable correlation with both components of the baryonic mass at kpc scales (i.e., the stellar mass density, and the molecular gas mass density; $\Sigma_{\ast}$, and $\Sigma_{\rm mol}$, respectively) for galaxies in the nearby Universe. In this study we propose an empirical relation between $\Sigma_{\rm SFR}$ and the baryonic mass surface density ($\Sigma_{\rm b}$ =$\Sigma_{\rm mol,Av}$ + $\Sigma_{\ast}$; where $\Sigma_{\rm mol,Av}$ is the molecular gas density derived from the optical extinction, Av) at kpc scales using the spatially-resolved properties of the MaNGA survey - the largest sample of galaxies observed via Integral Field Spectroscopy (IFS, $\sim$ 8400 objects). We find that $\Sigma_{\rm SFR}$ tightly correlates with $\Sigma_{\rm b}$. Furthermore, we derive an empirical relation between the $\Sigma_{\rm SFR}$ and a second degree polynomial of $\Sigma_{\rm b}$ yielding a one-to-one relation between these two observables. Both, $\Sigma_{\rm b}$ and its polynomial form show a stronger correlation and smaller scatter with respect to $\Sigma_{\rm SFR}$ than the relations derived using the individual components of $\Sigma_{\rm b}$. Our results suggest that indeed these three parameters are physically correlated, suggesting a scenario in which the two components of the baryonic mass regulate the star-formation activity at kpc scales.