# Two families of elliptical plasma lenses

## TL;DR

This paper explores two new elliptical plasma lens models, demonstrating how ellipticity influences lensing effects and magnification complexity through numerical analysis and parameter space investigation.

## Contribution

It introduces and analyzes two families of elliptical plasma lenses, expanding beyond axisymmetric models to include softened power-law and exponential distributions.

## Key findings

- Ellipticity enhances lensing effects.
- Increased complexity in magnification maps.
- Number of critical curves depends on ellipticity.

## Abstract

Plasma lensing is the refraction of low-frequency electromagnetic rays due to free electrons in the interstellar medium. Although the phenomenon has a distinct similarity to gravitational lensing, particularly in its mathematical description, plasma lensing introduces other additional features, such as wavelength dependence, radial rather than tangential image distortions, and strong demagnification of background sources. Axisymmetrical models of plasma lenses have been well-studied in the literature, but density distributions with more complicated shapes can provide new and exotic image configurations and increase the richness of the magnification properties. As a first step towards non-axisymmetrical distributions, we study two families of elliptical plasma lens, softened power-law and exponential plasma distributions. We perform numerical studies on each lens model, and present them over a parameter space. In addition to deriving elliptical plasma lens formulae, we also investigate the number of critical curves that the lens can produce by studying the lens parameter space, in particular the dependence on the lensing ellipticity. We find that the introduction of ellipticity into the plasma distribution can enhance the lensing effects as well as the complexity of the magnification map.