Constraining the parameters of binary systems through time-dependent light deflection

TL;DR

This paper develops a method to analyze time-dependent light deflection caused by active galactic cores, aiming to improve constraints on super-massive black hole binaries using astronomical interferometry.

Contribution

It introduces a new observational technique based on light deflection to constrain SMBHB parameters, comparing its effectiveness with existing methods.

Findings

The technique can outperform previous methods under ideal conditions.

It can produce measurable results with current VLBI technology.

The method's accuracy depends on observational circumstances.

Abstract

A theory is derived relating the configuration of the cores of active galaxies, specifically candidates for presumed super-massive black hole binaries (SMBHBs), to time-dependent changes in images of those galaxies. Three deflection quantities, resulting from the monopole term, mass quadrupole term, and spin dipole term of the core, are examined. The resulting observational technique is applied to the galaxy 3C66B. This technique is found to under idealized circumstances surpass the technique proposed by Jenet et al. in accuracy for constraining the mass of SMBHB candidates, but is exceeded in accuracy and precision by Jenet's technique under currently-understood likely conditions. The technique can also under favorable circumstances produce results measurable by currently-available astronomical interferometry such as very-long baseline-interferometry (VLBI).