Understanding ISM metallicities&nebular emission lines at z 6 using ALMA+JWST synergy | Ryan Sanders

The ISM metallicity is a fundamental property that is crucial for interpreting the dust and cold gas content of galaxies, understanding nebular line emission, and probing the cycle of baryons. Inferences on metallicity from JWST/NIRSpec spectra alone via strong emission lines will be severely limited by strong systematic biases. I will introduce a method to obtain accurate metallicities at z=6-9 by combining rest-optical lines from JWST with IR fine-structure [OIII]88um,52um lines from ALMA, using the electron temperature method. With accurate metallicities, we can connect metallicity and dust content; interpreting high [OIII]/[CII] ratios; understand the ionizing spectrum of massive stars; probe feedback/outflows; and construct empirical calibrations needed to interpret spectra from JWST.