Abstract

Recent years have seen a rapid expansion of new results from JWST , which have revolutionised our understanding of galaxy evolution in the first few billion years of the Universe. While many of these major results originated from large scale surveys, a few detailed case studies of individual galaxies (or compact groups) have been performed using the NIR Spec IFU . Here, I will detail two such studies of very different objects: the z= 7.152 galaxy system B14 -65666 (also known as Big Three Dragons) as observed in the GA-NIFS survey and one of the most distant little red dots (LRDs) known (UNCOVER_20466; z=8.5) as observed in the BlackTHUNDER survey. Line and continuum emission in Big Three Dragons is resolved into two strong cores surrounded by diffuse emission, as seen in recent JWST /NIRCam imaging. Our data constrain the gas-phase metallicity (_{20-30% solar) and SFR for each region. This source lies on the mass-metallicity relation at z>4, suggesting an evolved nature. The two core galaxies show contrasting properties, suggesting distinct evolutionary pathways. We confirm that UNCOVER _20466 is an LRD containing an overmassive black hole, and find that its extremely high [OIII]4363/HGamma ratio is indicative of not only AGN photoionization and heating, but also extremely high densities (ne}10^7cm-3).