Resolving Complex Inner X-ray Structure of the Gravitationaly Lensed AGN MGB2016+112

TL;DR

This study uses Chandra X-ray observations of a gravitationally lensed system to resolve its complex inner structure, revealing at least two X-ray sources likely representing a dual AGN or an AGN with a jet, with high positional accuracy.

Contribution

The paper introduces a novel application of gravitational lensing and statistical methods to measure metric distances at high redshift in X-ray astronomy with unprecedented precision.

Findings

Detection of at least two X-ray sources consistent with VLBI components.

Sources separated by approximately 200 parsecs.

Achieved high-accuracy measurements of source positions within tens of parsecs.

Abstract

We use a Chandra X-ray observation of the gravitationally lensed system MGB2016+112 at z=3.273 to elucidate presence of at least two X-ray sources. We find that these sources are consistent with the VLBI components measured by \citet{Spingola19}, which are separated by $\sim 200$ pc. Their intrinsic 0.5 -- 7 keV source frame luminosities are 2.6$\times$10$^{43}$ and 4.2$\times$10$^{44}$ erg s$^{-1}$. Most likely this system contains a dual active galactic nucleus (AGN), but we possibly are detecting an AGN plus a pc-scale X-ray jet, the latter lying in a region at very high magnification. The quadruply lensed X-ray source is within $\pm$40 pc (1$\sigma$) of its VLBI counterpart. Using a gravitational lens as a telescope, and a novel statistical application, we have achieved unprecedented accuracy for measuring metric distances at such large redshifts in X-ray astronomy, which is tens of mas if the source is located close to the caustics, while it is of hundreds of mas if the source is in a region at lower amplification. The present demonstration of this approach has implications for future X-ray investigations of large numbers of lensed systems.