We present the correlations between stellar mass , star formation rate ( SFR ) and [ N II ] /H \alpha flux ratio as indicator of gas-phase metallicity for a sample of 222 galaxies at 0.8 < z < 2.6 and \log ( M _ { * } / \mathrm { M } _ { \odot } ) = 9.0 - 11.5 from the LUCI , SINS/zC-SINF and KMOS ^ { \mathrm { 3 D } } surveys .
This sample provides a unique analysis of the mass-metallicity relation ( MZR ) over an extended redshift range using consistent data analysis techniques and strong-line metallicity indicator .
We find a constant slope at the low-mass end of the relation and can fully describe its redshift evolution through the evolution of the characteristic turnover mass where the relation begins to flatten at the asymptotic metallicity .
At fixed mass and redshift , our data do not show a correlation between the [ N II ] /H \alpha ratio and SFR , which disagrees with the 0.2-0.3 dex offset in [ N II ] /H \alpha predicted by the “ fundamental relation ” between stellar mass , SFR and metallicity discussed in recent literature .
However , the overall evolution towards lower [ N II ] /H \alpha at earlier times does broadly agree with these predictions .