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Related papers: Angular Broadening of Nearby Pulsars

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We apply a theory of wave propagation through a turbulent medium to the scattering of radio waves in pulsar magnetospheres. We find that under conditions of strong density modulation the effects of magnetospheric scintillations in…

Astrophysics · Physics 2009-10-31 Maxim Lyutikov , Anuj Parikh

Interstellar scattering causes pulsar profiles to grow asymmetrically, thus affecting the pulsar timing residuals, and is strongest at lower frequencies. Different Interstellar medium models predict different frequency ($\nu$) and…

High Energy Astrophysical Phenomena · Physics 2019-05-01 Karishma Bansal , G. B. Taylor , Kevin Stovall , Jayce Dowell

Extreme Scattering Events are radio-wave lensing events caused by AU-sized concentrations of ionised gas. Although they were discovered more than a decade ago we still have no clear picture of the physical nature of the lenses. To…

Astrophysics · Physics 2007-05-23 Mark A. Walker

The scattering of small bodies by planets is an important dynamical process in planetary systems. We present an analytical model to describe this process using the simplifying assumption that each particle's dynamics is dominated by a…

Earth and Planetary Astrophysics · Physics 2015-06-03 A. Bonsor , M. C. Wyatt

Recent pulsar scintillation measurements from Ooty, in conjunction with those from Parkes and other large radio telescopes, are used for a systematic investigation of the Local Interstellar Medium (LISM) towards the general direction of the…

Astrophysics · Physics 2009-11-07 N. D. Ramesh Bhat , Yashwant Gupta

The aim of our work was to study the spatial structure of inhomogeneities of interstellar plasma in the directions of five pulsars: B0823+26, B0834+06, B1237+25, B1929+10, and B2016+28. Observations of these pulsars were made with…

Observations reveal a uniform Kolmogorov turbulence throughout the diffuse ionized interstellar medium (ISM) and supersonic turbulence preferentially located in the Galactic plane. Correspondingly, we consider the Galactic distribution of…

Astrophysics of Galaxies · Physics 2017-01-25 Siyao Xu , Bing Zhang

We have conducted an angular differential imaging survey with NIRC2 at Keck in search of close-in substellar companions to a sample of seven systems with confirmed planetary-mass companions (PMCs) on wide orbits (>50 AU). These…

Earth and Planetary Astrophysics · Physics 2016-08-17 Marta L. Bryan , Brendan P. Bowler , Heather A. Knutson , Adam L. Kraus , Sasha Hinkley , Dimitri Mawet , Eric L. Nielsen , Sarah C. Blunt

The pulsed radio emission from the Galactic Center (GC) magnetar SGR J1745-29 probes the turbulent, magnetized plasma of the GC hyperstrong scattering screen through both angular and temporal broadening. We present the first measurements of…

Annual variations of interstellar scintillation can be modelled to constrain parameters of the ionized interstellar medium. If a pulsar is in a binary system, then investigating the orbital parameters is possible through analysis of the…

The scattering by the inner accretion disk of X-ray radiation generated near the surface of a spinning neutron star in a low-mass X-ray binary (LMXB) has observable effects on the waveforms of millisecond X-ray flux oscillations produced…

Astrophysics · Physics 2009-10-31 Sergei Y. Sazonov , Rashid A. Sunyaev

We report wideband scatter-broadening estimates of 14 pulsars towards the Gum nebula region using the Band-3 of the upgraded GMRT. This work increases the measurements of frequency scaling index of scatter-broadening ($\alpha$) across the…

High Energy Astrophysical Phenomena · Physics 2026-02-04 M. A. Krishnakumar , Bhal Chandra Joshi , P. K. Manoharan

Despite some success in explaining the observed polarisation angle swing of radio pulsars within the geometric rotating vector model, many deviations from the expected S-like swing are observed. In this paper we provide a simple and…

Solar and Stellar Astrophysics · Physics 2009-11-13 A. Karastergiou

Observations of pulsar scintillation are among the few astrophysical probes of very small-scale ($\lesssim$ au) phenomena in the interstellar medium (ISM). In particular, characterization of scintillation arcs, including their curvature and…

High Energy Astrophysical Phenomena · Physics 2023-11-28 S. K. Ocker , J. M. Cordes , S. Chatterjee , D. R. Stinebring , T. Dolch , V. Pelgrims , J. W. McKee , C. Giannakopoulos , D. J. Reardon

We show that surface waves along interstellar current sheets closely aligned with the line of sight lead to pulsar scintillation properties consistent with those observed. This mechanism naturally produces the length and density scales of…

Astrophysics of Galaxies · Physics 2015-06-15 Ue-Li Pen , Yuri Levin

The low-frequency profiles of some pulsars manifest temporal broadening due to scattering, usually accompanied by flat polarization position angle (PA) curves. Assuming that the scattering works on the 4 Stokes parameters in the same way,…

Astrophysics · Physics 2008-11-26 X. H. Li , J. L. Han

We have measured variations in scattering time scales in the Crab Pulsar over a 30-year period, using observations made at 610 MHz with the 42-ft telescope at Jodrell Bank Observatory. Over more recent years, where regular Lovell Telescope…

High Energy Astrophysical Phenomena · Physics 2018-07-18 J. W. McKee , A. G. Lyne , B. W. Stappers , C. G. Bassa , C. A. Jordan

Several stars show deep transits consistent with discs of roughly 1 Solar radius seen at moderate inclinations, likely surrounding planets on eccentric orbits. We show that this configuration arises naturally as a result of planet-planet…

Earth and Planetary Astrophysics · Physics 2024-05-16 Alexander J. Mustill , Melvyn B. Davies , Matthew A. Kenworthy

We use radio-wave scattering data to constrain the distribution of ionized gas in the outer Galaxy. Like previous models, our model for the H II disk includes parameters for the radial scale length and scale height of the H II, but we allow…

Astrophysics · Physics 2009-10-30 T. Joseph W. Lazio , James M. Cordes

We have made angular broadening measurements in the satellite line of the OH molecule at 1612 MHz of 8 OH/IR stars located near the Galactic Center with the Very Large Array. Early observations with the Very Long Baseline Array had revealed…

Astrophysics · Physics 2009-10-22 D. A. Frail , P. J. Diamond , J. M. Cordes , H. J. Van Langevelde