A speckle hologram of the interstellar plasma

Desai, K. M.; Gwinn, C. R.; Reynolds, J. E.; King, E. A.; Jauncey, D. L.; Flanagan, C. S.; Nicolson, G. D.; Preston, R. A.; Jones, Dayton L.

doi:10.1086/186455

Cited by 42 publications

(37 citation statements)

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“…We therefore average over $3200 independent scintillation elements. Refractive scintillation modulates flux density over a wide bandwidth and has a timescale $25 days (Desai et al 1992). This was shorter than the total span of the observations, but much longer than the span of any one observation.…”

Section: Scintillationmentioning

confidence: 98%

Correlation between X‐Ray Light‐Curve Shape and Radio Arrival Time in the Vela Pulsar

Lommen¹,

Donovan²,

Gwinn³

et al. 2007

ApJ

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We report the results of simultaneous observations of the Vela pulsar in X-rays and radio from the RXTE satellite and the Mount Pleasant Radio Observatory in Tasmania. We sought correlations between Vela's X-ray emission and radio arrival times on a pulse-by-pulse basis. At a confidence level of 99.8% we have found significantly higher flux density in Vela's main X-ray peak during radio pulses that arrived early. This excess flux shifts to the ''trough'' following the second X-ray peak during radio pulses that arrive later. Our results suggest that the mechanism producing the radio pulses is intimately connected to the mechanism producing X-rays. Current models using resonant absorption of radio emission in the outer magnetosphere as a cause of the X-ray emission are explored as a possible explanation for the correlation.

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Section: Scintillationmentioning

confidence: 98%

Correlation between X‐Ray Light‐Curve Shape and Radio Arrival Time in the Vela Pulsar

Lommen¹,

Donovan²,

Gwinn³

et al. 2007

ApJ

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“…Theoretical studies were made by, e.g., Prokhorov et al (1975); Rickett (1977); ; Narayan & Goodman c 2016 The Authors (1989); Gwinn et al (1998). Observational studies were made with the ground-based VLBI for extragalactic radio sources (e.g., Ojha et al 2006;Lazio et al 2008;Pushkarev et al 2013;Pushkarev & Kovalev 2015), the galactic center Sgr A * (e.g., Lo et al 1998;Bower et al 2006;Gwinn et al 2014;Pushkarev & Kovalev 2015), and pulsars (e.g., Kondratiev et al 2007;Gwinn et al 1993;Desai et al 1992;Bartel et al 1985).…”

Section: Introductionmentioning

confidence: 99%

PSR B0329+54: substructure in the scatter-broadened image discovered with RadioAstron on baselines up to 330 000 km

Попов

Bartel

Gwinn

et al. 2016

Mon. Not. R. Astron. Soc.

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We have resolved the scatter-broadened image of PSR B0329+54 and detected substructure within it. These results are not influenced by any extended structure of a source but instead are directly attributed to the interstellar medium. We obtained these results at 324 MHz with the ground-space interferometer RadioAstron which included the space radio telescope (SRT), ground-based Westerbork Synthesis Radio Telescope and 64-m Kalyazin Radio Telescope on baseline projections up to 330,000 km in 2013 November 22 and 2014 January 1 to 2. At short 15,000 to 35,000 km groundspace baseline projections the visibility amplitude decreases with baseline length providing a direct measurement of the size of the scattering disk of 4.8 ± 0.8 mas. At longer baselines no visibility detections from the scattering disk would be expected. However, significant detections were obtained with visibility amplitudes of 3 to 5% of the maximum scattered around a mean and approximately constant up to 330,000 km. These visibilities reflect substructure from scattering in the interstellar medium and offer a new probe of ionized interstellar material. The size of the diffraction spot near Earth is 17, 000 ± 3, 000 km. With the assumption of turbulent irregularities in the plasma of the interstellar medium, we estimate that the effective scattering screen is located 0.6 ± 0.1 of the distance from Earth toward the pulsar.

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“…This assumption is based on the result of Desai et al (1992) that the scattering material could be associated with the shell of the Vela SNR (see Sect. 2).…”

Section: Discussionmentioning

confidence: 99%

“…It should be noted, however, that the result of Desai et al (1992) was derived from use of scintillation observables (see Blanford & Narayan 1985;Gwinn et al 1993). The referee (J. Cordes) pointed out that the quite large uncertainties in observables result in uncertainty in the value of the parameter x.…”

Section: Discussionmentioning

confidence: 99%

“…We assume that the deformation lies on the approaching side of the Vela SNR's shell and suggest that the turbulent material associated with the shell deformation is responsible for the scattering of the Vela pulsar (cf. Desai et al 1992). The line of sight extent of the scattering material could be estimated to be 1.2-1.7 pc (for D = 500 pc) given that the width of the filament is 2 -3 (Milne 1995;Bock et al 1998) and assuming that the characteristic size of the shell deformation is 40 -50 .…”

Section: Scintillation and Proper Motion Velocitiesmentioning

confidence: 99%

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On the velocity of the Vela pulsar

Gvaramadze

2001

A&A

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Abstract. It is shown that if the shell of the Vela supernova remnant is responsible for nearly all the scattering of the Vela pulsar, then the scintillation and proper motion velocities of the pulsar can only be reconciled with each other in the case of nonzero transverse velocity of the scattering material. A possible origin of large-scale transverse motions in the shell of the Vela supernova remnant is discussed.

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A speckle hologram of the interstellar plasma

Cited by 42 publications

References 0 publications

Correlation between X‐Ray Light‐Curve Shape and Radio Arrival Time in the Vela Pulsar

Correlation between X‐Ray Light‐Curve Shape and Radio Arrival Time in the Vela Pulsar

PSR B0329+54: substructure in the scatter-broadened image discovered with RadioAstron on baselines up to 330 000 km

On the velocity of the Vela pulsar

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