Morphology of solar system scale plasma lenses in the interstellar medium: a test from pulsar scintillation parabolic arcs

Scintillation spectra of some pulsars have suggested the existence of ≲ AU scale density structures in the ionized interstellar medium, whose astrophysical correspondence is still a mystery. The detailed study of Brisken et al. suggested two possible morphologies for these structures: A parallel set of filaments or sheets (the ‘parallel stripes model’), or a filament broken up into denser knots (t...