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Related papers: The Microarcsecond Sky and Cosmic Turbulence

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We develop the theory of interstellar scintillation as caused by an irregular plasma having a power-law spatial density spectrum with a spectral exponent of 4 corresponding to a medium with abrupt changes in its density. An ``outer scale''…

Astrophysics · Physics 2009-10-31 Hendrik Lambert , Barney Rickett

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

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 study the propagation of radio waves through a medium possessing density fluctuations that are elongated along the ambient magnetic field and described by an anisotropic Goldreich-Sridhar power spectrum. We derive general formulas for…

Astrophysics · Physics 2009-11-07 B. D. G. Chandran , D. C. Backer

Recently, there have been reports of six bright, dispersed bursts of coherent radio emission found in pulsar surveys with the Parkes Multi-beam Receiver. Not much is known about the progenitors of these bursts, but they are…

High Energy Astrophysical Phenomena · Physics 2013-09-10 T. E. Hassall , E. F. Keane , R. P. Fender

An observer, situated several thousand light-years away from a radio pulsar, finds himself embedded in the diffraction pattern resulting from the propagation of the radio waves through the irregular interstellar medium. The observer's…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Redouane Fakir

We demostrate that the measurement of fluctuations of polarization due to the galactic interstellar scintillations may be used to study the structure of the radiation field at compact radio sources. We develop a mathematical formalism and…

Astrophysics · Physics 2009-10-31 Mikhail V. Medvedev

The SKA will be a state of the art radiotelescope optimized for both large area surveys as well as for deep pointed observations. In this paper we analyze the impact that the SKA will have on Galactic studies, starting from the immense…

We discuss optimal detection of fast radio transients from astrophysical objects while taking into account the effects of propagation through intervening ionized media, including dispersion, scattering and scintillation.Our analysis applies…

Astrophysics · Physics 2009-11-07 J. M. Cordes , M. A. McLaughlin

The Square Kilometer Array will have the sensitivity, spatial resolution, and frequency resolution to provide new scientific knowledge of evolved stars. Four basic areas of scientific exploration are enhanced by the construction of the SKA:…

Astrophysics · Physics 2009-11-10 Kevin Marvel

High resolution X-ray imaging offers a unique opportunity to probe the nature of dust in the z ~< 2 universe. Dust grains 0.1- 1 um in size will scatter soft X-rays, producing a diffuse "halo" image around an X-ray point source, with a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Lia Corrales , Frits Paerels

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

Supplemented with suitable buffering techniques, the low-frequency part of the SKA can be used as an ultra-precise detector for cosmic-ray air showers at very high energies. This would enable a wealth of scientific applications: the physics…

Instrumentation and Methods for Astrophysics · Physics 2015-01-09 T. Huege , J. D. Bray , S. Buitink , R. Dallier , R. D. Ekers , H. Falcke , C. W. James , L. Martin , B. Revenu , O. Scholten , F. G. Schröder

We study three quasar radio sources (B1257-326, B1519-273, and J1819+385) that show large amplitude intraday and annual scintillation variability produced by the Earth's motion relative to turbulent-scattering screens located within a few…

Astrophysics · Physics 2009-11-13 Jeffrey L. Linsky , Barney J. Rickett , Seth Redfield

The circumgalactic medium (CGM) is poorly constrained at the sub-parsec scales relevant to turbulent energy dissipation and regulation of multi-phase structure. Fast radio bursts (FRBs) are sensitive to small-scale plasma density…

Astrophysics of Galaxies · Physics 2025-07-25 S. K. Ocker , M. Chen , S. P. Oh , P. Sharma

Absorption or emission against the cosmic microwave background radiation (CMB) may be observed in the redshifted 21cm line if the spin temperature of the neutral intergalactic medium prior to reionization differs from the CMB temperature.…

Astrophysics · Physics 2009-12-10 Tiziana Di Matteo , Rosalba Perna , Tom Abel , Martin J. Rees

Diffuse soft X-ray line emission is commonly used to trace the thermal and chemical properties of the hot interstellar medium, as well as its content, in nearby galaxies. Although resonant line scattering complicates the interpretation of…

Astrophysics of Galaxies · Physics 2018-07-25 Yang Chen , Q. Daniel Wang , Gao-Yuan Zhang , Shuinai Zhang , Li Ji

Deep surveys with the SKA1-MID array offer for the first time the opportunity to systematically explore the polarization properties of the microJy source population. Our knowledge of the polarized sky approaching these levels is still very…

The propagation of radio waves from distant compact radio sources through turbulent interstellar plasma in our Galaxy causes these sources to twinkle, a phenomenon called interstellar scintillation. Such scintillations are a unique probe of…