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Seminarium odbywa się w Piwnicach w sali wykładowej budynku Radioastronomii. Początek o godzinie 11.15.
Udział w seminarium w trybie zdalnym za pośrednictwem BigBlueButton (BBB).

14 kwietnia 2025

“Radio-emitting active galactic nuclei at milliarcsecond-scale resolution”

dr Krisztina Gabányi
Department of Astronomy, ELTE, Eotvos University, Budapeszt, Węgry
HUN-REN-ELTE Extragalactic Research Group, ELTE, Eotvos University, Budapeszt, Węgry
Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences, Budapeszt, Węgry
Instytut Astronomii, Uniwersytet Mikołaja Kopernika, Toruń, Polska

Streszczenie:
Today the Very Long Baseline Interferometry (VLBI) technique provides the highest achievable resolution in astronomy. In studying the radio emission of active galactic nuclei (AGN), VLBI can deliver accurate positions, reveal the origin of the radio emission, help to discriminate between star formation and AGN-related emission, expose the details of jet structure at levels at least tens of parsecs and, as recently demonstrated, can image the black hole shadow.
In my talk, I will focus on two topics. First, how various radio interferometric observations can help to find dual AGN or refute such claims in individual objects. According to the current structure formation model, galaxies are formed via the merger of smaller ones, thus it is expected that the dual (or multiple) systems of their central supermassive black holes (SMBH) can form. During the interaction process, numerical simulations show that at least one of the SMBHs becomes active at less than 10 kpc separation. I will present a few cases to illustrate the power and shortcomings of radio observations in this field.
Second, I will show how radio interferometric observations can help to study AGN at high redshifts, z>4. These studies provide essential constraints for the formation and evolution of SMBHs and can reveal the interaction between the jets and the dense material surrounding powerful jetted AGN.