Colloquium by Sushmita Agarwal

You are cordially invited to a colloquium by Sushmita Agarwal.

Title: "Eyes on the High-Energy Universe: Probing the origin of variable emission in relativistic astrophysical jets".

Abstract:

"Relativistic jetted systems are natural laboratories for extreme particle acceleration processes. Powered by a central engine, they are strong emitters across the electromagnetic spectrum. Their emission originates from energy dissipation and particle acceleration mechanisms operating in situ at considerable distances from the black hole.
In the case of radio-loud active galactic nuclei (AGNs), particularly blazars, the specific alignment of the jets with respect to the observer results in relativistically boosted emission, making them observable out to high redshifts. In this talk, I will discuss how blazars serve as effective probes for investigating the origin of variable high-energy emission in AGNs, the underlying particle acceleration processes, and the role of the external jet environment in sustaining this variability. I will explore how such variability provides insights into the emission mechanisms of gravitationally lensed blazars at redshifts of up to 2.5. Additionally, I will highlight the potential of wide-field scanning facilities such as Fermi-LAT in identifying new high-energy and very-high-energy emitters, which is increasingly relevant in the current era of multi-messenger astronomy".