1. Milliarcsecond X-Ray Astrometry to Resolve Inner Regions of AGN at z > 1 Using Gravitational Lensing
- Author
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Cristiana Spingola, Daniel Schwartz, and Anna Barnacka
- Subjects
Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We report the localization of the X-ray emission from two strongly lensed AGN, CLASS B0712+472 ($z=1.34$) and CLASS B1608+656 ($z=1.394$). We obtain milliarcsecond X-ray astrometry by developing a novel method that combines parametric lens modelling with a Bayesian analysis. We spatially locate the X-ray sources in CLASS B0712+472 and CLASS B1608+656 within 11 mas and 9 mas from the radio source, respectively. For CLASS B0712+472, we find that the X-ray emission is co-spatial with the radio and optical emission. While, in CLASS B1608+656, the X-ray emission is co-spatial with radio, but displaced with respect to the optical emission at 1$\sigma$ level, which positions this source as an offset AGN candidate. This high astrometric precision improves on the limitations of existing X-ray instruments by two orders of magnitude. The demonstrated method opens a path to search for offset and binary AGN at $z>1$, and to directly test supermassive black hole formation models in a redshift range that has been mostly underconstrained to date., Comment: 16 pages, 7 figures. Accepted for publication in ApJ
- Published
- 2022