The evolution and dependence of the local mass-metallicity relation

We present a sample of 86 111 star-forming galaxies (SFGs) selected from the catalogue of the MPA4111.1 emission-line measurements for SDSS DR7 to investigate the evolution of mass-metallicity (MZ) relation. We rind that: under the log(L-H alpha) > 41.0 threshold, the 0.04 < z <= 0.06 SFGs with 9.2 < log(M star/M-circle dot) < 9.5 have always higher metallicities (similar to 0.1 dex) than the 0.10 < z < 0.12 SFGs by using the closely matched control sample method; under the log(L-[O III]) > 39.7 threshold, the 0,04 < z <= 0,06 SFGs with 9.2 < log(M star/M-circle dot) < 9.5 do not exhibit the evolution of the MZ relation, in contrast to the 0.10 < z < 0.12 SFGs. We find that the mat-Illicit)/tends to be lower in galaxies with a higher concentration, higher Sersic index, or higher SFR. In addition, we can see that the stellar mass and metallicity usually present. higher in galaxies with a higher D(n)4000 or higher log(N/0) ratio. Moreover, we present the two galaxy populations with log(M star/M-circle dot) below 10.0 or greater than 10.5 in the MZ relation, showing clearly an anticorrelation and a positive correlation between specific star formation rate and 12 + log(O/H).