Pulsar lensing geometry

We test the inclined sheet pulsar scintillation model (Pen & Levin) against archival very long baseline interferometry (VLBI) data on PSR 0834+06 and show that its scintillation properties can be precisely reproduced by a model in which refraction occurs on two distinct lens planes. These data s...

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Main Authors: Liu, S., Pen, U., Macquart, Jean-Pierre, Brisken, W., Deller, A.
Format: Journal Article
Published: Oxford University Press 2016
Online Access:http://purl.org/au-research/grants/arc/DP140104114
http://hdl.handle.net/20.500.11937/3120
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author Liu, S.
Pen, U.
Macquart, Jean-Pierre
Brisken, W.
Deller, A.
author_facet Liu, S.
Pen, U.
Macquart, Jean-Pierre
Brisken, W.
Deller, A.
author_sort Liu, S.
building Curtin Institutional Repository
collection Online Access
description We test the inclined sheet pulsar scintillation model (Pen & Levin) against archival very long baseline interferometry (VLBI) data on PSR 0834+06 and show that its scintillation properties can be precisely reproduced by a model in which refraction occurs on two distinct lens planes. These data strongly favour a model in which grazing-incidence refraction instead of diffraction off turbulent structures is 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 interstellar medium (ISM) screen transverse velocity. The results are consistent with ISM velocities local to the PSR 0834+06 sight-line (through the Galaxy). The simple 1-D 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 first time) a direct measurement of the distance of the pulsar. For most of the recycled millisecond pulsars that are the targets of precision timing observations, the targets where independent distance measurements are not available. The degeneracy presented in the lens modelling could be broken if the pulsar resides in a binary system.
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spelling curtin-20.500.11937-31202022-10-12T03:44:13Z Pulsar lensing geometry Liu, S. Pen, U. Macquart, Jean-Pierre Brisken, W. Deller, A. We test the inclined sheet pulsar scintillation model (Pen & Levin) against archival very long baseline interferometry (VLBI) data on PSR 0834+06 and show that its scintillation properties can be precisely reproduced by a model in which refraction occurs on two distinct lens planes. These data strongly favour a model in which grazing-incidence refraction instead of diffraction off turbulent structures is 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 interstellar medium (ISM) screen transverse velocity. The results are consistent with ISM velocities local to the PSR 0834+06 sight-line (through the Galaxy). The simple 1-D 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 first time) a direct measurement of the distance of the pulsar. For most of the recycled millisecond pulsars that are the targets of precision timing observations, the targets where independent distance measurements are not available. The degeneracy presented in the lens modelling could be broken if the pulsar resides in a binary system. 2016 Journal Article http://hdl.handle.net/20.500.11937/3120 10.1093/mnras/stw314 http://purl.org/au-research/grants/arc/DP140104114 Oxford University Press fulltext
spellingShingle Liu, S.
Pen, U.
Macquart, Jean-Pierre
Brisken, W.
Deller, A.
Pulsar lensing geometry
title Pulsar lensing geometry
title_full Pulsar lensing geometry
title_fullStr Pulsar lensing geometry
title_full_unstemmed Pulsar lensing geometry
title_short Pulsar lensing geometry
title_sort pulsar lensing geometry
url http://purl.org/au-research/grants/arc/DP140104114
http://hdl.handle.net/20.500.11937/3120