English
Related papers

Related papers: Interferometric Visibility of a Scintillating Sour…

200 papers

To date, the search for radio technosignatures has focused on sky location as a primary discriminant between technosignature candidates and anthropogenic radio frequency interference (RFI). In this work, we investigate the possibility of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-19 Bryan Brzycki , Andrew P. V. Siemion , Imke de Pater , James M. Cordes , Vishal Gajjar , Brian Lacki , Sofia Sheikh

We are undertaking a large-scale 5 GHz VLA survey of the northern sky to search for rapid intra-day variability (IDV). Over four observing epochs we found that 56% of the sources showed variability on timescales of hours to several days.…

Diffractive and refractive magnetospheric scintillations may allow a direct testing of the plasma inside the light cylinder. Unusual electrodynamics of the strongly magnetized electron-positron plasma allow separation of the magnetospheric…

Astrophysics · Physics 2009-10-31 Maxim Lyutikov

We use cyclic spectroscopy to perform high frequency-resolution analyses of multi-hour baseband Arecibo observations of the millisecond pulsar PSR B1937+21. This technique allows for the examination of scintillation features in far greater…

We conducted a very long baseline interferometric observation of 5 nearby pulsars and did not resolve the scattering disks of any of these sources. Using our upper limits on the angular diameters of these scattering disks and published…

Astrophysics · Physics 2018-07-18 M. C. Britton , C. R. Gwinn , M. J. Ojeda

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

Visibility scintillation resulting from wave propagation through the turbulent ionosphere can be an important sources of noise at low radio frequencies ($\nu\lesssim 200$ MHz). Many low frequency experiments are underway to detect the power…

Instrumentation and Methods for Astrophysics · Physics 2016-03-16 H. K. Vedantham , L. V. E. Koopmans

The observed interstellar scintillation pattern of an intra-day variable radio source is influenced by its source structure. If the velocity of the interstellar medium responsible for the scattering is comparable to the earth's, the vector…

Astrophysics · Physics 2009-11-07 J-P Macquart , D. L. Jauncey

While sensing in high temporal resolution is necessary for wide range of application, it is still limited nowadays due to cameras sampling rate. In this work we try to increase the temporal resolution beyond the Nyquist frequency, which is…

Signal Processing · Electrical Eng. & Systems 2022-11-28 Khen Cohen , Dan Raviv , David Mendlovic

Scintillation of compact radio sources results from the interference between images caused by multipath propagation, and probes the intervening scattering plasma and the velocities of the emitting source and scattering screen. In…

High Energy Astrophysical Phenomena · Physics 2021-11-23 R. A. Main , G. H. Hilmarsson , V. R. Marthi , L. G. Spitler , R. S. Wharton , S. Bethapudi , D. Z. Li , H. -H. Lin

Surveys for transient and variable phenomena can be confounded by the presence of extrinsic variability such as refractive interstellar scintillation (RISS). We have developed an all-sky model for RISS which can predict variability on a…

Astrophysics of Galaxies · Physics 2019-07-26 P. J. Hancock , E. G. Charlton , J-P. Macquart , N. Hurley-Walker

Radio waves propagating from distant pulsars in the interstellar medium (ISM), are refracted by electron density inhomogeneities, so that the intensity of observed pulses fluctuates with time. The theory relating the observed pulse…

Astrophysics · Physics 2009-11-10 Stanislav Boldyrev , Carl R. Gwinn

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 dynamic and secondary spectra of many pulsars show evidence for long-lived, aligned images of the pulsar that are stationary on a thin scattering sheet. One explanation for this phenomenon considers the effects of wave crests along…

Astrophysics of Galaxies · Physics 2018-05-16 Dana Simard , Ue-Li Pen

Backscatter limits many interferometric measurements, including gravitational wave detectors, by creating spurious interference. We describe an experimental method to directly and quantitatively measure the backscatter interference. We…

Optics · Physics 2022-04-29 Michal Was , Eleonora Polini

If identical photons meet at a semi-transparent mirror they appear to leave in the same direction, an effect called "two-photon interference". It has been known for some time that this effect should occur for photons generated by dissimilar…

Quantum Physics · Physics 2010-06-07 A. J. Bennett , R. B. Patel , C. A. Nicoll , D. A. Ritchie , A. J. Shields

The temporal smearing of impulsive radio events at cosmological redshifts probes the properties of the ionized Inter-Galactic Medium (IGM). We relate the degree of temporal smearing and the profile of a scattered source to the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Jean-Pierre Macquart , Jun-Yi Koay

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

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…

We present the results of flux density monitoring of PSR B0329+54 at the frequency of 4.8 GHz using the 32-meter TCfA radiotelescope. The observations were conducted between 2002 and 2005. The main goal of the project was to find…

Astrophysics of Galaxies · Physics 2015-05-28 Wojciech Lewandowski , Jaroslaw Kijak , Yashwant Gupta , Krzysztof Krzeszowski
‹ Prev 1 4 5 6 7 8 10 Next ›