Extreme scattering events from axisymmetric plasma lenses

Understand

Frequency-dependent brightness fluctuations of radio sources, the so-called extreme scattering events (ESEs), have been observed over the last three decades.

• They are caused by Galactic plasma structures whose geometry and origin are still poorly understood.
• In this paper, we construct axisymmentric two-dimensional (2D) column density profiles for the plasma lens and explore the resulting ESEs for both point-like and extended sources.
• A quantity that becomes relevant is the impact parameter $b$, namely the distance of the observer's path from the lens symmetry axis.