English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Spherical plasma lens models are known to suffer from a severe over-pressureproblem, with some observations requiring lenses with central pressures up tomillions of times in excess of the ambient ISM. There are two ways that lensmodels can solve the over-pressure problem: a confinement mechanism exists tocounter the internal pressure of the lens, or the lens has a unique geometry,such that the projected column-density appears large to an observer. Thisoccurs with highly asymmetric models, such as edge-on sheets or filaments, withpotentially low volume-density. In the first part of this work we investigatethe ability of non-magnetized plasma filaments to mimic the magnification ofsources seen behind spherical lenses and we extend a theorem from gravitationallens studies regarding this model degeneracy. We find that for plasma lenses,the theorem produces unphysical charge density distributions. In the secondpart of the work, we consider the plasma lens over-pressure problem. Usingmagnetohydrodynamics, we develop a non self-gravitating model filament confinedby a helical magnetic field. We use toy models in the force-free limit toillustrate novel lensing properties. Generally, magnetized filaments may act aslenses in any orientation with respect to the observer, with the most highdensity events produced from filaments with axes near the line of sight. Wefocus on filaments that are perpendicular to the line of sight that show thetoroidal magnetic field component may be observed via the lens rotationmeasure.

Magnetized Filament Models for Diverging Plasma Lenses