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The parsec scales of AGN as seen using strong lensing and VLBI
Cristiana Spingola (IRA)
Tuesday 19/05/2020 @ 14:00, Sala IV piano Battiferro
The centres of galaxies are powerful laboratories to test models of galaxy formation, but also the interplay between supermassive black holes and their host galaxies. While these sub-galactic scales can be directly investigated in the local Universe, it is observationally extremely difficult to access them at high redshift. In this talk, we will exploit the combination of strong gravitational lensing and very long baseline interferometry (VLBI) technique to directly study the parsec scale emission in active galaxies at z > 1. The magnifying effect of strong lensing and the milliarcsecond angular resolution of VLBI observations allow us to spatially resolve the central parts of distant lensed galaxies, especially if they are located in the region at highest magnification. Therefore, it becomes possible to unveil dual AGN candidates, offset-AGN and faint extended jets embedded in molecular gas reservoirs at cosmological distances. Nevertheless, this kind of studies is currently limited by the small number statistics. We will also discuss how to search for more radio-loud lensing systems in current and future wide-field VLBI surveys.
Link to the recorded talk: youtu.be/zxlnAvNA0sQ