Unveiling the population of dual and lensed active galactic nuclei at sub-arcsec separations is an exciting Nature paper featuring the LBT AO system at work. The team describes a new selection method to obtain a sample of dual/lensed active galactic nuclei (AGN) candidates with sub-arcsecond separations from the Gaia data.  This method looks for AGNs showing multiple peaks in the light profiles observed by the Gaia satellite. This new method, dubbed the Gaia Multipeak method. (GMP), substantially increases the known number of dual AGNs, with implications for studies of in-spiraling supermassive black holes.  High resolution images of a sample of GMP candidates are obtained with the LBT with spatial resolutions ~0.1″, revealing the presence of multiple targets with separations between 0.33-0.66″, confirming the method.  Studies of these dual and lensed AGN’s are of importance in many field in astrophysics and cosmology, including but not limited to, understanding the nature of dark matter and measurement of the Hubble constant.

High-resolution, AO-assisted LBT images of 5 GMP-selected systems in the Ks band. Each panel is 2.2″× 2.2″ wide. The labels report the redshift
of the primary component and the angular separation.

The paper is available here:

https://www.nature.com/articles/s41550-022-01761-5

Unveiling the population of dual and lensed active galactic nuclei at sub-arcsec separations
F. Mannucci, E. Pancino, F. Belfiore, C. Cicone, A. Ciurlo, G. Cresci, E. Lusso, A. Marasco, A. Marconi, E. Nardini, E. Pinna, P. Severgnini, P. Saracco, G. Tozzi & S. Yeh
Nature Astronomy

Published: 25 August 2022