Connecting disc-corona physics and ionised outflows in AGN in the 2040s

TL;DR

This paper advocates for next-generation spectroscopic surveys in the 2040s to study the connection between accretion disc physics, X-ray corona, and ionised outflows in AGN, using multi-wavelength and time-domain observations.

Contribution

It proposes a comprehensive observational strategy and requirements for a future ESO facility to connect AGN accretion physics with nebular and circumgalactic medium properties.

Findings

Identifies key spectral and temporal diagnostics for AGN states.

Suggests a large-scale survey of 10^4–10^5 AGN with multi-wavelength coverage.

Defines technical requirements for future telescopes in the 2040s.

Abstract

We outline a science case for next-generation wide-field spectroscopic surveys aimed at connecting the physics of the accretion disc and X-ray corona in active galactic nuclei (AGN) with the properties of their nebular regions and circumgalactic medium (CGM). We focus on the non-linear Lx-Luv relation and on deviations from this canonical coupling encoded in $\Delta \alpha_{OX}$, the offset of the optical-to-X-ray index from the mean relation, and propose to use broad and narrow line emission and CGM nebulae as calorimeters of the ionising SED to trace different accretion "states". We propose an observational strategy based on rest-frame UV/optical spectroscopy of $\sim 10^{4}-10^{5}$ AGN, a time-domain reverberation-mapping tier for a well-defined subsample, coordinated X-ray coverage, and wide-field IFU mapping of CGM emission (including H$\alpha$ and Ly$\alpha$). From these goals we derive requirements for a future ESO facility in the 2040s: a dedicated, wide-field, high-multiplex optical-NIR spectroscopic telescope with time-domain flexibility and arcmin-scale IFU capability.