Coffee talks
Friday 27/09/2019 @ 11:30, Sala riunioni quarto piano
Cristiana Spingola (University of Bologna / IRA-INAF), "Probing structure and formation of AGN using gravitationally lensed radio jets"
Spatially resolved observations of radio jets can provide important clues on the formation of AGN. According to the hierarchical structure formation scenario, SMBHs can be created as a result of a major merger of two galaxies, each with its own nuclear black hole. As a consequence of this model, it is expected to observe binary SMBH systems as an intermediate stage of such formation process. However, binary SMBH systems are difficult to observe and have low detection rate. Nevertheless, by combining the power of strong gravitational lensing and VLBI at cm-wavelengths, we have likely detected the first example of a merging binary SMBH system in the early Universe. I will present multi-epoch VLBI, ALMA and VLT MUSE observations and discuss some preliminary results on such singular lensing system. Moreover, spatially resolved observations of relativistic jets in gamma-ray-loud AGN are a powerful tool to investigate where the high-energy emission comes from. However, high angular resolution observations of the innermost regions of AGN can be currently achieved only for a few bright and nearby objects. By exploiting the magnification provided by gravitational lensing it is possible to access these scales also in high redshift blazars. I will briefly talk about the results of multi-wavelength VLBI monitoring programs of two gamma-ray-loud gravitationally lensed blazars, and introduce my post-doc project (on this topic) here at INAF-IRA.