Discovery and Characterization of Galactic-scale Dual Supermassive Black Holes Across Cosmic Time

TL;DR

This paper discusses the potential of the Roman Space Telescope's High Latitude Wide Area Survey to discover and study dual supermassive black hole systems across cosmic time, shedding light on galaxy and SMBH evolution.

Contribution

It outlines the scientific opportunities and technical requirements for identifying and characterizing SMBH pairs at galactic scales over a wide redshift and luminosity range.

Findings

Roman survey will enable detection of SMBH pairs at various redshifts.

The study will improve understanding of SMBH formation and galaxy evolution.

Technical specifications are outlined for future observations.

Abstract

The hierarchical structure formation paradigm predicts the formation of pairs of supermassive black holes in merging galaxies. When both (or one) members of the SMBH pair are unobscured AGNs, the system can be identified as a dual (or offset) AGN. Quantifying the abundance of these AGN pairs as functions of separation, redshift and host properties is crucial to understanding SMBH formation and AGN fueling in the broad context of galaxy formation. The High Latitude Wide Area Survey with Roman, with its unprecedented combination of sensitivity, spatial resolution, area and NIR wavelength coverage, will revolutionize the study of galactic-scale environments of SMBH pairs. This white paper summarizes the science opportunities and technical requirements on the discovery and characterization of SMBH pairs down to galactic scales (i.e., less than tens of kpc) over broad ranges of redshift (1<z<7) and luminosity (Lbol>1E42 erg/s).