The mass-metallicity relation of Lyman-break analogues and its
  dependence on galaxy properties
  We investigate the mass-metallicity relation and its dependence on galaxy
physical properties with a sample of 703 Lyman-break analogues (LBAs) in local
Universe, which have similar properties to high redshift star-forming galaxies.
The sample is selected according to $\ha$ luminosity, $L(\ha)>10^{41.8}\,{\rm
erg\,s^{-1}}$, and surface brightness, $I(\ha)>10^{40.5}\,{\rm
erg\,s^{-1}\,kpc^{-2}}$, criteria. The mass-metallicity relation of LBAs
harmoniously agrees with that of star-forming galaxies at $z \sim$ 1.4-1.7 in
stellar mass range of $10^{8.5}M_{\odot}<M_{*}<10^{11}M_{\odot}$. The relation
between stellar mass, metallicity and star formation rate of our sample is
roughly consistent with the local fundamental metallicity relation. We find
that the mass-metallicity relation shows a strong correlation with the
4000\AA\, break; galaxies with higher 4000\AA\, break typically have higher
metallicity at a fixed mass, by 0.06 dex in average. This trend is independent
of the methodology of metallicity. We also use the metallicity estimated by
$T_{\rm e}$-method to confirm it. The scatter in mass-metallicity relation can
be reduced from 0.091 to 0.077 dex by a three-dimensional relation between
stellar mass, metallicity and 4000\AA\, break. The reduction of scatter in
mass-metallicity relation suggests that the galaxy stellar age plays an
important role as the second parameter in the mass-metallicity relation of
LBAs.
