Quantify the impact of jet components on SMBHB detectability

Evaluate how incorporating one or two relativistic jet components into the binary advection-dominated accretion flow spectral energy distribution model affects the detectability of sub-parsec supermassive black hole binaries with ground and spaceborne very-long-baseline interferometry.

Background

The paper’s binary spectral energy distribution model includes emission from the circumbinary disc and the two minidiscs but does not include jets. Because many very-long-baseline interferometry sources are associated with relativistic jets, adding jet emission could alter both the total and correlated flux densities, potentially expanding the detectable binary parameter space.

Jet launching introduces additional emission and geometric parameters, and the paper notes that the dynamics underlying jet launching remain uncertain. A systematic assessment is therefore needed to determine whether jets improve detectability, change the inferred binary signatures, or introduce additional degeneracies in visibility-domain modelling.

References

There is also remaining uncertainty in the dynamics behind jet launching. In Section \ref{ss:jets} we briefly consider the implications of adding one or two jets to the model, but further evaluation of the impact to SMBHB detectability is left for future work.

— Supermassive black hole binaries in the multi-messenger context of ground and spaceborne VLBI  (2609.08704 - Hudson et al., 8 Sep 2026) in Section 2, subsection “Model Parameters” (Section 2.1)

The interplay of these effects for VLBI detectability requires more exploration and we leave this for future work.

— Supermassive black hole binaries in the multi-messenger context of ground and spaceborne VLBI  (2609.08704 - Hudson et al., 8 Sep 2026) in Section 4.1, “Inclination Effects”