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Related papers: Interstellar scintillation as a probe of microarcs…

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Around 10% of bright low-frequency radio sources observed with the Murchison Widefield Array (MWA) show strong Interplanetary Scintillation (IPS) on timescales of a few seconds, implying that almost all their low-frequency radio emission…

Astrophysics of Galaxies · Physics 2018-11-28 Elaine M. Sadler , Rajan Chhetri , John Morgan , Elizabeth K. Mahony , Thomas H. Jarrett , Steven Tingay

We summarize results from flux density monitoring campaigns performed with the 100 meter radio-telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties of the rapid variability from…

Astrophysics · Physics 2009-11-07 T. P. Krichbaum , A. Kraus , L. Fuhrmann , G. Cimo , A. Witzel

Gravitation could modulate the interstellar scintillation of pulsars in a way that is analogous to refractive interstellar scintillation (RISS). While RISS occurs when a large ionized cloud crosses the pulsar line-of-sight, gravitational…

Astrophysics · Physics 2008-05-26 Redouane Al Fakir

Due to the inhomogeneity of electron number density, radio waves emitted by pulsars undergo scattering as they pass through the interstellar medium (ISM). However, a connection between large-scale pulsar scattering data and the structure of…

Astrophysics of Galaxies · Physics 2025-02-14 Qiuyi He , Xun Shi , Guangxing Li

We report the first astrophysical application of the technique of wide-field Interplanetary Scintillation (IPS) with the Murchison Widefield Array (MWA). This powerful technique allows us to identify and measure sub-arcsecond compact…

High Energy Astrophysical Phenomena · Physics 2018-01-10 R. Chhetri , J. Morgan , R. D. Ekers , J-P Macquart , E. M. Sadler , M. Giroletti , J. R. Callingham , S. J. Tingay

We determine the small-scale structure for a large sample of Compact Steep Spectrum (CSS) and Gigahertz Peaked Spectrum (GPS) sources and a sample of larger radio sources at 327 MHz using the technique of Inter-Planetary Scintillation (IPS)…

Astrophysics · Physics 2007-05-23 S. Jeyakumar , D. J. Saikia , A. Pramesh Rao , V. Balasubramanian

We present here the results from an extensive scintillation study of twenty pulsars in the dispersion measure (DM) range 3 - 35 pc cm^-3 carried out using the Ooty Radio Telescope, to investigate the distribution of ionized material in the…

Astrophysics · Physics 2009-10-30 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao

A sample of 123 radio sources that exhibit significant variations at 1.4 GHz on a seven year base-line has been created using FIRST VLA B-array data from 1995 and 2002 on a strip at dec=0 near the south Galactic cap. This sample spans the…

Astrophysics · Physics 2009-11-10 W. H. de Vries , R. H. Becker , R. L. White , D. J. Helfand

The RadioAstron space radio telescope provides a unique opportunity to study the extreme brightness temperatures ($\mathrm{T_B }$) in AGNs with unprecedented long baselines of up to 28 Earth diameters. Since interstellar scintillation (ISS)…

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

Several radio-wave scintillation phenomena exhibit properties which are difficult to accommodate within the standard propagation model based on distributed Kolmogorov turbulence in the ionised ISM; here we discuss one such phenomenon,…

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

We present a fitting function to describe the statistics of flux modulations caused by interstellar scintillation. The function models a very general quantity: the cross-correlation of the flux observed from a compact radio source of finite…

Astrophysics · Physics 2009-11-13 J. Goodman , R. Narayan

Extreme scattering events (ESEs) in the interstellar medium (ISM) were first observed in regular flux measurements of compact extragalactic sources. They are characterized by a flux variation over a period of weeks, suggesting the passage…

Variability of radio-emitting active galactic nuclei can be used to probe both intrinsic variations arising from shocks, flares, and other changes in emission from regions surrounding the central supermassive black hole, as well as…

High Energy Astrophysical Phenomena · Physics 2015-01-21 Hayley Bignall , Steve Croft , Talvikki Hovatta , Jun Yi Koay , Joseph Lazio , Jean-Pierre Macquart , Cormac Reynolds

We report the discovery of fast, frequency-dependent intensity variations from the scintillating intra-day variable quasar J1819+3845 at a wavelength of 21cm which resemble diffractive interstellar scintillations observed in pulsars. The…

Astrophysics · Physics 2009-11-11 Jean-Pierre Macquart , Ger de Bruyn

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

Pulsars are the only cosmic radio sources known to be sufficiently compact to show diffractive interstellar scintillations. Images of the variance of radio signals in both time and frequency can be used to detect pulsars in large-scale…

Instrumentation and Methods for Astrophysics · Physics 2016-08-17 S. Dai , S. Johnston , M. E. Bell , W. A. Coles , G. Hobbs , R. D. Ekers , E. Lenc

Ionospheric scintillation is the rapid change in the phase and/or the amplitude of a radio signal as it passes through small scale plasma density irregularities in the ionosphere. These scintillations not only can reduce the accuracy of…

Atmospheric and Oceanic Physics · Physics 2012-08-10 S. Priyadarshi , A. K. Singh

We present the interstellar scintillation analysis of fast radio burst (FRB) 20220912A during its extremely active episode in 2022 using data from the Five-hundred-meter Aperture Spherical Radio Telescope (FAST). We detect a scintillation…

Keane et al. (2016) have recently reported the discovery of a new fast radio burst, FRB150418, with a promising radio counterpart at 5.5 and 7.5 GHz -- a rapidly decaying source, falling from 200-300 $\mu$Jy to 100 $\mu$Jy on timescales of…

High Energy Astrophysical Phenomena · Physics 2016-06-08 Kazunori Akiyama , Michael D. Johnson
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