Pulsar lensing geometry

Abstract

Our analysis of archival VLBI data of PSR 0834+06 revealed that its scintillation properties can be precisely modelled using the inclined sheet model (Pen & Levin 2014), resulting in two distinct lens planes. These data strongly favour the grazing sheet model over turbulence as the primary source of pulsar scattering. This model can reproduce the parameters of the observed diffractive scintillation with an accuracy at the percent level. Comparison with new VLBI proper motion results in a direct measure of the ionized ISM screen transverse velocity. The results are consistent with ISM velocities local to the PSR 0834+06 sight-line (through the Galaxy). The simple 1D structure of the lenses opens up the possibility of using interstellar lenses as precision probes for pulsar lens mapping, precision transverse motions in the ISM, and new opportunities for removing scattering to improve pulsar timing. We describe the parameters and observables of this double screen system. While relative screen distances can in principle be accurately determined, a global conformal distance degeneracy exists that allows a rescaling of the absolute distance scale. For PSR B0834+06, we present VLBI astrometry results that provide (for the fist time) a direct measurement of the distance of the pulsar. For targets where independent distance measurements are not available, which are the cases for most of the recycled millisecond pulsars that are the targets of precision timing observations, the degeneracy presented in the lens modelling could be broken if the pulsar resides in a binary system.

11 pages, 12 figures

References in corpus (4)

• Tests of general relativity from timing the double pulsar
• Folded Fields as the Source of Extreme Radio-Wave Scattering in the Galactic Center
• Interstellar Holography
• From pulsar scintillations to coronal heating: discontinuities in magnetohydrodynamics

Cited by in corpus (29)

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• First detection of frequency-dependent, time-variable dispersion measures
• Predicting Pulsar Scintillation from Refractive Plasma Sheets
• Extreme radio-wave scattering associated with hot stars
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• Pulsar scintillation studies with LOFAR. I. The census
• The effects of plasma lensing on the inferred dispersion measures of Fast Radio Bursts
• Noodle Model for Scintillation Arcs
• The $\theta$-$\theta$ Diagram: Transforming pulsar scintillation spectra to coordinates on highly anisotropic interstellar scattering screens
• The Thousand-Pulsar-Array programme on MeerKAT -- X. Scintillation arcs of 107 pulsars
• Revealing compact structures of interstellar plasma in the Galaxy with RadioAstron
• The Frequency Dependence of Scintillation Arc Thickness in Pulsar B1133+16
• Disentangling interstellar plasma screens with pulsar VLBI: Combining auto- and cross-correlations
• Pulsar Double-lensing Sheds Light on the Origin of Extreme Scattering Events
• Plasma microlensing dynamic spectrum probing fine structures in the ionized interstellar medium
• High Resolution VLBI Astrometry of pulsar scintillation screens with the $\theta -\theta$ Transform
• On the double-plane plasma lensing
• Scintillation of PSR B1508+55 -- the view from a 10,000-km baseline
• NE2025: An Updated Electron Density Model for the Galactic Interstellar Medium
• Scintillation Arc Brightness and Electron Density for an Analytical Noodle Model
• Plasma lensing with magnetic field and a small correction to the Faraday rotation measurement
• The Galactic distribution of pulsar scattering and the $\tau -\mathrm{DM}$ relation
• Testing Gravity with Pulsar Scintillation Measurements
• Associations Between Scattering Screens and Interstellar Medium Filaments
• A direct measurement of the electron density turbulence parameter $C_1$ and implications for the emission size of the magnetar XTE J1810-197
• Using Giant Pulses to Measure the Impulse Response of the Interstellar Medium
• A Census of Pulsars in Possible Association with Galactic Open Clusters
• Morphology of solar system scale plasma lenses in the interstellar medium: a test from pulsar scintillation parabolic arcs
• Plasma lensing modeling of substructures on pulsar scintillation screens