The MOSDEF survey: the mass–metallicity relationship and the existence of the FMR at <i>z</i> ∼ 1.5

We analyze the rest-optical emission-line ratios of z~1.5 galaxies drawn from MOSFIRE Deep Evolution Field (MOSDEF) survey. Using composite spectra we investigate mass-metallicity relation (MZR) at and measure its evolution to z=0. When using gas-phase metallicities based on N2 line ratio, find that MZR z=0 depends stellar mass, evolving by $\Delta\rm log(\rm O/H)\sim0.25$ dex $M_*<10^{9.75}M_{\odot}$ down O/H)\sim0.05$ $M_*>10^{10.5}M_{\odot}$. In contrast, O3N2-based shows a constant offset O/H)\sim0.30$ across all masses, consistent with previous MOSDEF results independent metallicity indicators, suggesting O3N2 provides more robust calibration for our sample. investigated secondary dependence SFR measuring correlated scatter about mean $M_*$-specific $M_*-\log(\rm O3N2)$ relations. an anti-correlation between $\log(\rm O/H)$ sSFR offsets, indicating presence $M_*$-SFR-Z relation, though limited significance. Additionally, stacks lie along sequence fixed $\mu=\log(M_*/M_{\odot})-0.6\times\log(\rm / M_{\odot} yr^{-1})$ can be described fundamental (FMR). However, different calibrations shift calculated off local FMR, appropriate are essential understanding redshift. Finally, how [NII]/H$\alpha$ scales galaxy properties is crucial accurately describe effects blended [NII] H$\alpha$ redshift flux measurements in future large surveys utilizing low-resolution such as Euclid Roman Space Telescope.