Oral Presentation

AGN Demographics Across Cosmic Time: Insights from JWST and the Promise of PFS

Author(s): Helena Treiber (Princeton University)

Presenter: Helena Treiber (Princeton University)

The first years of JWST have transformed our view of AGN at high redshift (z > 3), revealing unprecedented populations and new tensions in our understanding of SMBH growth. A missing puzzle piece remains: large demographic studies of growing black holes and their galaxies at cosmic noon, a realm that PFS is uniquely poised to explore. We begin by presenting AGN demographics at 3<z<10 based on JWST NIRSpec+MIRI data. We highlight the strengths, weaknesses, and complementarity of UV narrow line, optical broad line, and mid-IR power-law selections for measuring BH mass density and BH-galaxy scaling relations in the first billion years. Because of significant photoionization modeling uncertainties and complex selection functions, conclusions based on high-z narrow line selections are tenuous. High-z AGN are surprisingly weak in X-ray, making detections rare. Mid-infrared selection remains promising but suffers from modeling uncertainties, the necessary depth, and host galaxy contribution. To build an unbiased view of AGN across cosmic time, we need demographic studies with clear selections. Cosmic noon is critical, bridging the gap between local well-understood populations and the puzzles of the JWST z>3 studies.
PFS is therefore essential for assembling robust AGN samples and advancing our understanding of SMBH growth at z > 1.