Astronomy & Astrophysics Seminar: The origin of the radio emission in radio-quiet quasars

Zoom: https://tau-ac-il.zoom.us/j/87185167411?pwd=FpTUyIgXaOturzOFSetA6pPVYQilen.1

Abstract:

Radio-quiet active galactic nuclei (AGN) represent the majority (~ 90%) of the AGN population. The radio emission in radio-quiet AGN can be produced by a variety of mechanisms, including the host galaxy star formation, thermal free-free emission from AGN photoionized gas, an AGN-driven wind interacting with the interstellar medium, a low-power jet, and the accretion disk coronal activity. Radio observations are a powerful tool to study the wide variety of physical mechanisms and to investigate the magnetic field and the synchrotron radiation of the relativistic electrons from the scale close to the supermassive black hole to the host galaxy scale. My current study focuses on the 1-24 GHz parsec-scale radio spectra of a representative sample of radio-quiet quasars, based on our Very Long Baseline Array (VLBA) observations. I will present how to constrain the size of the radio emitting region using the radio spectra, to distinguish the potential radio emission mechanisms on parsec scales. Future studies will be expanded to larger scales.

Seminar Organizer: Dr. Jonathan Stern