Dual-Component Plasma Lens Models

Abstract

In contrast to the converging, achromatic behaviour of axisymmetric gravitational lenses, diverging frequency-dependent lensing occurs from refraction due to a distribution of over-dense axisymmetric plasma along an observer's line of sight. Such plasma lenses are particularly interesting from the point of view of astronomical observations because they can both magnify and dim the appearance of background sources as a function of frequency. Plasma lensing is believed to be involved in a number of separate phenomena involving the scintillation of radio pulsars, extreme scattering events of background radio sources and may also play a role in the generation of fast radio bursts. These lensing phenomena are believed to occur in dense environments, in which there may be many density perturbations between an observer and background source. In this work we generalize individual plasma lens models to produce dual component lenses using families of plasma lens models previously studied in the literature, namely the exponential and softened power-law lenses. Similar to binary gravitational lens models, these dual component plasma lenses feature a rich and complex critical and caustic morphology, as well as generate more complicated light curves. We map the number of criticals formed for a given component separation and angular size, and highlight a relevant degeneracy between two particular models. This work provides an argument in favor of close monitoring of extreme scattering events in progress in order to break such model degeneracies.

19 pages, 20 figures, accepted for publication in MNRAS. Comments welcome!

References in corpus (23)

• Interstellar Turbulence II: Implications and Effects
• Frequency-dependent effects of gravitational lensing within plasma
• Lensing of Fast Radio Bursts by Plasma Structures in Host Galaxies
• The Gaussian Plasma Lens in Astrophysics. Refraction
• Astrophysical Applications of Gravitational Microlensing
• Effects of plasma on gravitational lensing
• Pulsar Observations of Extreme Scattering Events
• Pulsar scintillations from corrugated reconnection sheets in the ISM
• Pulsar emission amplified and resolved by plasma lensing in an eclipsing binary
• Two families of astrophysical diverging lens models
• Gravitational radiospectrometer
• A Second Chromatic Timing Event of Interstellar Origin toward PSR J1713+0747
• Atomic and Ionized Microstructures in the Diffuse Interstellar Medium
• Escape and Trapping of Low-Frequency Gravitationally Lensed Rays by Compact Objects within Plasma
• Extreme Scattering Events Towards Two Young Pulsars
• Predicting Pulsar Scintillation from Refractive Plasma Sheets
• Gravitational Lensing of Rays through the Levitating Atmospheres of Compact Objects
• Extreme radio-wave scattering associated with hot stars
• The NANOGrav 11-Year Data Set: Arecibo Observatory Polarimetry And Pulse Microcomponents
• Extreme scattering events from axisymmetric plasma lenses
• The peculiar light-curve of J1415+1320: A case study in extreme scattering events
• Caustics of $1/r^n$ binary gravitational lenses: from galactic haloes to exotic matter
• Induced Polarization from Birefringent Pulse Splitting in Magnetoionic Media

Cited by in corpus (10)

• The Physics of Fast Radio Bursts
• Hills and holes in the microlensing light curve due to plasma environment around gravitational lens
• The effects of plasma lensing on the inferred dispersion measures of Fast Radio Bursts
• Two families of elliptical plasma lenses
• Time delay induced by plasma in strong lens systems
• On the double-plane plasma lensing
• The Multiple Images of the Plasma Lensing FRB
• Magnetized Filament Models for Diverging Plasma Lenses
• Bias in apparent dispersion measure due to de-magnification of plasma lensing on background radio sources
• Investigating Extreme Scattering Events by Volumetric Ray-tracing