The Mass-Metallicity Relation revisited with CALIFA
  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.
