LAM seminar by Andy Bunker: The high redshift frontier with JWST – studying the most distant galaxies with NIRSpec

Title: The high redshift frontier with JWST – studying the most distant galaxies with NIRSpec

Abstract:

I will give an overview of results on the highest redshift galaxies from the Guaranteed Time Observations of the NIRSpec Instrument Science Team, including those co-ordinated with the NIRCam Team as part of the JWST Advanced Deep Extragalactic Survey (JADES). We have used the multi-object microshutters on NIRSpec to target several thousand galaxies in the GOODS fields, including several hundred at redshifts beyond 6 (within the epoch of reionization) and have spectroscopically confirmed galaxies beyond redshift 14 for the first time (including a very UV-luminous galaxy at z=14, where bursty star formation or potentially a top-heavy initial mass function may be brightening the UV). NIRSpec spectroscopy at 1-5microns is sensitive to rest-optical emission lines over a wide range of redshifts and means that we can study the evolution of dust attenuation, star formation rates, metallicity, chemical abundances, ionization and excitation mechanism in galaxies out to high redshifts. Highlights include discovery of a nebular-dominated Balmer jump galaxy at z~6 with possibly a top-heavy IMF, and GNz11 at z=10.6 with Ly-alpha in emission and elevated N/O.