Description
Thanks to the exquisite capabilities of ALMA observatory, we were able to study dusty galaxies at EoR through their dust continuum and FIR emission lines. With these observations, a rapid buildup of dust in the early Universe. Until the launch of JWST, studying the rest-frame of optical emission of these sources was out of reach for astronomers.
In this talk, I will present one of the first JWST/NIRSpec IFS data of a massive dusty star-forming galaxy at the Epoch of Reionisation. COS-3018 (Laporte+18, Witstok+22), a luminous dusty object at z~6.8, previously only observed using ALMA ([CII]158 microns, [OIII] 88 microns). These observations revealed a massive dust reservoir (log Mdust =7.9 Msol), challenging theoretical models on how to build such a dust mass so early in the Universe.
In this talk, I will present deep high-resolution JWST/NIRSpec IFS observations of rest-frame UV and optical continuum and emission lines, in combination with deep ALMA [CII] and [OIII]88micron observations and NIRCam photometry, which enable us a comprehensive look into the both cold and hot ISM, its ionisation source (AGN or metal poor starburst?), metallicity gradient, densities and full kinematics comparison of the hot and cold gas. Furthermore, I will present first evidence of nitrogen enrichment from small star-forming clusters observed at high redshift. Finally, I will answer the question: What is driving such an extreme production of dust and UV luminosity in this galaxy, starburst or AGN and how did this galaxy produce so much dust and metals so quickly?
