# The Mass-Metallicity Relation revisited with CALIFA

## TL;DR

This study revisits the mass-metallicity relation using spatially resolved spectroscopy from CALIFA, finding no significant secondary dependence on star formation rate and discussing possible reasons for previous conflicting results.

## Contribution

It provides an updated analysis of the mass-metallicity relation with integral field data, clarifying the role of star formation rate and challenging earlier claims of a secondary relation.

## Key findings

- No significant secondary relation with SFR or sSFR for most masses.
- Inconsistent with previous studies claiming a SFR-metallicity relation.
- Suggests aperture effects or local phenomena may explain earlier results.

## Abstract

We present an updated version of the mass--metallicity relation (MZR) using integral field spectroscopy data obtained from 734 galaxies observed by the CALIFA survey. These unparalleled spatially resolved spectroscopic data allow us to determine the metallicity at the same physical scale ($\mathrm{R_{e}}$) for different calibrators. We obtain MZ relations with similar shapes for all calibrators, once the scale factors among them are taken into account. We do not find any significant secondary relation of the MZR with either the star formation rate (SFR) or the specific SFR for any of the calibrators used in this study, based on the analysis of the residuals of the best fitted relation. However we do see a hint for a (s)SFR-dependent deviation of the MZ-relation at low masses (M$<$10$^{9.5}$M$_\odot$), where our sample is not complete. We are thus unable to confirm the results by Mannucci et al. (2010), although we cannot exclude that this result is due to the differences in the analysed datasets. In contrast, our results are inconsistent with the results by Lara-Lopez et al. (2010), and we can exclude the presence of a SFR-Mass-Oxygen abundance Fundamental Plane. These results agree with previous findings suggesting that either (1) the secondary relation with the SFR could be induced by an aperture effect in single fiber/aperture spectroscopic surveys, (2) it could be related to a local effect confined to the central regions of galaxies, or (3) it is just restricted to the low-mass regime, or a combination of the three effects.