A quasar-galaxy merger at z~6.2: JWST unveils the rapid growth of black holes and massive galaxies in the early Universe
Roberto Decarli (INAF - OAS)
Tuesday 09/04/2024 @ 14:00, Sala Antonio Sollima (IV piano Battiferro)
Quasar host galaxies are among the most active astrophysical sources in the early Universe. The black holes at their centers have already grown to masses of ~1e9 Msun. These black holes reside in some of the most massive galaxies emerging from the reionization. Here I will present a JWST/NIRSpec IFU study of PJ308-21, a quasar at z~6.2 that is observed in the act of merging with satellite galaxies. The NIRSpec data offer a superb-S/N rest-frame optical spectrum of the quasar, and a spatially-resolved map of various optical emission lines (Halpha, Hbeta, [OIII], [NII], [SII], HeII). Our analysis unveils a critical phase in the build-up of the quasar, its host, and the circumgalactic medium surrounding the system. This study showcases the transformative role of JWST observations in our understanding of galaxy formation in the first Gyr of the Universe's history.