A Klever probe of the ISM in high-z galaxies
We will present KLEVER, an ESO Large Programme aimed at investigating dynamics, gas excitation properties and chemical abundances in high redshift galaxies, by means of near-IR spatially resolved spectroscopy. Exploiting KMOS multi-IFU observations in the J,H and K bands we aim to map multiple optical rest-frame emission lines (from [O II]3727 to [S III]9530) in a sample of ~200 galaxies between 1.2 < z < 2.5. The survey targets both gravitationally lensed galaxies in Frontier Fields clusters and non-lensed galaxies in the COMOS and GOODS fields.
We investigate the physical drivers responsible for the evolution in the emission line ratios by assessing whether the offsets from the local relations correlate with different properties like electron density, ionisation parameter and nitrogen abundance.
We also derive full metallicity maps, exploiting different calibrators and evaluate presence and evolution of metallicity gradients.
Although the bulk of the analysed galaxies are characterised by flat gradients, suggesting that efficient feedback and gas mixing processes are in place at these epochs, the irregular and non-axisymmetric patterns often seen in the full 2D metallicity maps suggests to move beyond the classical "radial-averages" approach to get meaningful constraints on galaxy evolution models and allow for fair comparison with prescriptions of high resolution simulations.