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Related papers: On Frequency-Dependent Dispersion Measures and Ext…

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We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand…

Astrophysics · Physics 2011-02-11 W. H. de Vries , S. S. Olivier , S. J. Asztalos , L. J. Rosenberg , K. L. Baker

The distribution of baryons in the Universe remains a fundamental open question in astronomy, and the dispersion measure (DM) of Fast Radio Bursts (FRBs) serves as a valuable tool for probing this cosmic gas. We investigate the impact of…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-05 Maryam Hussaini , Liam Connor , Ralf M. Konietzka , Vikram Ravi , Jakob Faber , Kritti Sharma , Myles Sherman

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

Pulsar dynamic spectra exhibit high visibility fringes arising from interference between scattered radio waves. These fringes may be random or highly ordered patterns, depending on the nature of the scattering or refraction. Here we…

Astrophysics · Physics 2009-11-10 Mark Walker , Dan Stinebring

We apply a pulsed-light interferometer to measure both the intensity and the phase of light that is transmitted through a strongly scattering disordered material. From a single set of measurements we obtain the time-resolved intensity,…

Disordered Systems and Neural Networks · Physics 2009-11-10 I. M. Vellekoop , P. Lodahl , A. Lagendijk

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

This paper considers scattering screens that have arbitrary spatial variations of scattering strength transverse to the line of sight, including screens that are spatially well confined, such as disks and filaments. We calculate the…

Astrophysics · Physics 2009-10-31 J. M. Cordes , T. Joseph W. Lazio

High precision cosmology with weak gravitational lensing requires a precise measure of the Point Spread Function across the imaging data where the accuracy to which high spatial frequency variation can be modelled is limited by the stellar…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Catherine Heymans , Barnaby Rowe , Henk Hoekstra , Lance Miller , Thomas Erben , Thomas Kitching , Ludovic Van Waerbeke

Turbulence is a vital part of the interstellar medium (ISM) of galaxies, contributing significantly to galaxy energy budgets and acting as a regulator of star formation. Despite this, little is understood about ISM turbulence empirically.…

Astrophysics of Galaxies · Physics 2021-07-26 Dana Simard , Vikram Ravi

Fast radio bursts are radio transients observed mainly around 1.5 GHz. Their peak frequency decreases at a rate of 100 ~ 500 MHz/s and some of them have a broader pulse with an exponentially decaying tail. Common assumptions for fast radio…

High Energy Astrophysical Phenomena · Physics 2017-08-30 Qiwu Song , Yu Huang , Hengqiang Feng , Lei Yang , Tuanhui Zhou , Qingyu Luo , Tengfei Song , Xuefei Zhang , Yu Liu , Guangli Huang

In this paper we introduce a new Python package, the Pulsar Signal Simulator, or PsrSigSim, which is designed to simulate a pulsar signal from emission at the pulsar, through the interstellar medium, to observation by a radio telescope, and…

High Energy Astrophysical Phenomena · Physics 2021-03-31 Brent J. Shapiro-Albert , Jeffrey S. Hazboun , Maura A. McLaughlin , Michael T. Lam

Temporal broadening is a commonly observed property of fast radio bursts (FRBs), associated with turbulent media which cause radiowave scattering. Similarly to dispersion, scattering is an important probe of the media along the line of…

Fast Radio Bursts (FRBs) are intense radio flashes from the sky that are characterized by millisecond durations and Jansky-level flux densities. We carried out a statistical analysis on FRBs discovered. Their mean dispersion measure, after…

High Energy Astrophysical Phenomena · Physics 2017-02-01 LongBiao Li , YongFeng Huang , ZhiBin Zhang , Di Li , Bing Li

Frequency-dependent brightness fluctuations of radio sources, the so-called extreme scattering events (ESEs), have been observed over the last three decades. They are caused by Galactic plasma structures whose geometry and origin are still…

Astrophysics of Galaxies · Physics 2018-09-12 Lingyi Dong , Maria Petropoulou , Dimitrios Giannios

We examine the proposal that the dispersion measures (DMs) and Faraday rotation measures (RMs) of extragalactic linearly-polarized fast radio bursts (FRBs) can be used to probe the intergalactic magnetic field (IGMF) in filaments of…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-29 Takuya Akahori , Dongsu Ryu , B. M. Gaensler

Observations of far-infrared (FIR) and submillimeter (SMM) polarized emission are used to study magnetic fields and dust grains in dense regions of the interstellar medium (ISM). These observations place constraints on models of molecular…

Astrophysics · Physics 2009-03-19 John E. Vaillancourt

This paper presents the analysis and characterization of the surface scattering process for both specular and diffused components. The study is focused on the investigation of various building materials each having a different roughness, at…

Signal Processing · Electrical Eng. & Systems 2017-10-17 Angelos A. Goulianos , Alberto L. Freire , Tom Barratt , Evangelos Mellios , Peter Cain , Moray Rumney , Andrew Nix , Mark Beach

Fast radio bursts (FRB) will become important cosmological tools, as the number of observed FRBs is increasing rapidly with more surveys being carried out. A large sample of FRBs with dispersion measures (DM) and rotation measures (RM) can…

Astrophysics of Galaxies · Physics 2024-10-02 Timea Orsolya Kovacs , Sui Ann Mao , Aritra Basu , Yik Ki Ma , Laura G. Spitler , Charles R. H. Walker

We present evidence of an extreme scattering event (ESE) toward PSR J2313+4253 using high-cadence observations taken with the Green Bank Observatory 20m telescope. The high density of observations in time allow for detailed tracking of the…

Diffusive Radiation is a new type of radiation predicted to occur in randomly inhomogeneous media due to the multiple scattering of pseudophotons. This theoretical effect is now observed experimentally. The radiation is generated by the…