The Colloquium takes place every Wednesday at 11:15 AM - Warsaw Copernicus Astronomical Centre online by means of Zoom platform. The Colloquium is given in English and chaired by dr Stanisław Bajtlik (bajtlik@camk.edu.pl). People from outside of the Copernicus Center are very welcome to participate. For technical detailes please contact Dr. Stanislaw Bajtlik.
Marzena Śniegowska (CAMK, Warsaw)
The time-dependent phenomena in Active Galactic Nuclei (AGN) are not yet well-understood. Those sources are massive, with a broad range of physical properties and observations across the entire electromagnetic spectrum to explore. I explore different timescales, from hours/days to the chemical evolution of the galaxy over millions of years. Short-term variations are observed in the form of Quasi-Periodic Eruptions (QPE) and changing look (CL) active galactic nuclei - CL AGN. I discuss the model of radiation pressure instability taking into account the presence of inner advection-dominated accretion flow (ADAF) or the presence of the magnetic field. The long-term evolution shows through the correlation between the observed accretion rate and the chemical composition. I address this issue by determining the metallicity of high accretion rate sources.
Journal Club takes place on Mondays at 11:10 AM in the Barek room. The seminar is given in English and is chaired by Jonas Pereira.