The evolution of metallicity and metallicity gradients from z = 2.7 to 0.6 with KMOS3D

摘要: We present measurements of the [N II]/H alpha ratio as a probe gas-phase oxygen abundance for sample 419 star-forming galaxies at z = 0.6-2.7 from KMOS3D near-IR multi-integral field unit (IFU) survey. The mass-metallicity relation (MZR) is determined consistently with same selection, metallicity tracer, and methodology over wide redshift range probed by find good agreement long-slit surveys in literature, except low-mass slope similar to 2.3, where this less biased than previous samples based on optical spectroscopic redshifts. In regime we measure steeper some literature results. Excluding contribution active galactic nuclei MZR reduces sensitivity high-mass end, but produces otherwise consistent There no significant dependence star formation rate. fixed stellar mass. IFU data allow spatially resolved alpha, which can infer gradients 180. galaxies, thus tripling current literature. observed are average flat, only 15 statistically offset zero > 3 sigma. have modeled effect beam. smearing, assuming smooth intrinsic radial gradient known seeing, inclination, effective radius each galaxy. Our seeing-limited observations recover up 70% largest, face-on disks, 30% smaller, more inclined galaxies. do not trends between or corrected any population, dynamical, structural galaxy parameters, mostly existing studies much smaller sizes. cosmological simulations, strong feedback generally required produce flat high redshift.