Description
AGN feedback remains a vital path for the quenching of galaxies in theoretical models. With the recent discovery of quiescent galaxies at z>3, identification of typical moderate AGNs at high redshift became more essential than ever, to explain the ever-growing population of quiescent galaxies. As typical selection techniques such as X-ray and radio observations are not sensitive enough to detect the typical AGN population at high redshifts (z>3), we need to rely on optical emission lines, which are not accessible to astronomers at these redshifts until the launch of JWST. However, typical selection techniques using optical emission lines (such as BPT diagram), fail to reliably select AGN due to low metallicities of galaxies at high redshift, hence the need to revisit AGN selection.
In this talk, I will present the results from the JWST Advanced Galactic Survey (JADES) and its deep NIRSpec/MSA observations of 500 galaxies between z~3-11. I will describe the selection of AGN host galaxies at high-z using these emission lines, to reliably distinguish between star-forming and AGN host galaxies. Using this unique state-of-the-art dataset, I will present the first characterisation of moderate luminosity AGN, the AGN driven outflows and their host galaxy properties (such as black-hole masses, star-formation rates, stellar mass, etc.) at high redshifts, tracing the AGN feedback in the first 3 billion years of Cosmic evolution. Lastly, I will present the analysis of deep JWST/NIRSpec and ALMA observations of a quiescent galaxy at z~3 to constrain its quenching pathway via strangulation.
