Hide-and-Seek with the Fundamental Metallicity Relation
  We use $\sim$83,000 star-forming galaxies at $0.04<z<0.3$ from the Sloan
Digital Sky Survey to study the so-called fundamental metallicity relation
(FMR) and report on the disappearance of its anti-correlation between
metallicity and star formation rate (SFR) when using the new metallicity
indicator recently proposed by Dopita et al. In this calibration, metallicity
is primarily sensitive to the emission line ratio [NII]$\lambda$6584 /
[SII]$\lambda\lambda$6717, 6731 that is insensitive to dilution by pristine
infalling gas that may drive the FMR anti-correlation with SFR. Therefore, we
conclude that the apparent disappearance of the FMR (using this new metallicity
indicator) does not rule out its existence.
