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Related papers: Imaging pulsar echoes at low frequencies

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The LOw FRequency ARray - LOFAR is a new radio telescope that is moving the science of radio pulsars and transients into a new phase. Its design places emphasis on digital hardware and flexible software instead of mechanical solutions.…

Instrumentation and Methods for Astrophysics · Physics 2012-07-03 Maciej Serylak , Aris Karastergiou , Chris Williams , Wes Armour , LOFAR Pulsar Working Group

Scintillation of pulsar radio signals caused by the interstellar medium can in principle be used for interstellar interferometry. Changes of the dynamic spectra as a function of pulsar longitude were in the past interpreted as having…

Intensity scintillations of cosmic radio sources are used to study astrophysical plasmas like the ionosphere, the solar wind, and the interstellar medium. Normally these observations are relatively narrow band. With Low Frequency Array…

Pulsar Timing Arrays use a set of millisecond pulsars in an attempt to directly detect nanohertz gravitational waves. For this purpose, high precision timing of the pulsars is essential and ultimately a precision of the order of ~100 ns is…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Lina Levin

The Low Frequency Array (LOFAR) is an ideal instrument to conduct deep extragalactic surveys. It has a large field of view and is sensitive to large scale and compact emission. It is, however, very challenging to synthesize thermal noise…

We present a novel, straightforward method for spatiotemporal characterization of ultra-short laser pulses. The method employs far-field interferometry and inverse Fourier transform spectroscopy, built on the theoretical basis derived in…

Interferometric scattering microscopy has been a very promising technology for highly sensitive label-free imaging of a broad spectrum of biological nanoparticles from proteins to viruses in a high-throughput manner. Although it can reveal…

Optics · Physics 2021-08-11 Celalettin Yurdakul , Haonan Zong , Yeran Bai , Ji-Xin Cheng , M. Selim Unlu

The parabolic structure of the secondary or conjugate spectra of pulsars is often the result of isolated one-dimensional (or at least highly anisotropic) lenses in the ISM. The curvature of these features contains information about the…

Instrumentation and Methods for Astrophysics · Physics 2023-07-11 Daniel Baker , Walter Brisken , Marten H. van Kerkwijk , Robert Main , Ue-Li Pen , Tim Sprenger , Olaf Wucknitz

In this work we adopted a CLEAN-based method to determine the scatter time, $\tau$, from archived pulsar profiles under both the thin screen and uniform medium scattering models and to calculate the scatter time frequency scale index…

High Energy Astrophysical Phenomena · Physics 2017-01-23 Jr-Wei Tsai , John H. Simonetti , Michael Kavic

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

Exoplanets orbiting M dwarf stars are a prime target in the search for life in the Universe. M dwarf stars are active, with powerful flares that could adversely impact prospects for life, though there are counter-arguments. Here, we turn…

Earth and Planetary Astrophysics · Physics 2018-02-28 William B. Sparks , Richard L. White , Roxana E. Lupu , Holland C. Ford

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

Radio waves are imprinted with propagation effects from ionized media through which they pass. Owing to electron density fluctuations, compact sources (pulsars, masers, and compact extragalactic sources) can display a wide variety of…

Astrophysics · Physics 2009-11-10 T. Joseph W. Lazio , J. M. Cordes , A. G. de Bruyn , J. -P. Macquart

Optical diffraction tomography is an indispensable tool for studying objects in three-dimensions due to its ability to accurately reconstruct scattering objects. Until now this technique has been limited to coherent light because spatial…

Planets reflect and linearly polarize the radiation that they receive from their host stars. The emergent polarization is sensitive to aspects of the planet atmosphere such as the gas composition and the occurrence of condensates and their…

Earth and Planetary Astrophysics · Physics 2018-02-28 Antonio García Muñoz

Signals from radio pulsars show a wavelength-dependent delay due to dispersion in the interstellar plasma. At a typical observing wavelength, this delay can vary by tens of microseconds on five-year time scales, far in excess of signals of…

The aim of our work was to study the spatial structure of inhomogeneities of interstellar plasma in the directions of five pulsars: B0823+26, B0834+06, B1237+25, B1929+10, and B2016+28. Observations of these pulsars were made with…

A real-time ranging lidar with 0.1 Mega Hertz update rate and few-micrometer resolution incorporating dispersive Fourier transformation and instantaneous microwave frequency measurement is proposed and demonstrated. As time-stretched…

Signal Processing · Electrical Eng. & Systems 2020-08-06 Lijie Zhao , Haiyun Xia , Yihua Hu , Tengfei Wu , Zhen Zhang , Jibo Han , Yunbin Wu , Tiancheng Luo

Observations of interplanetary scintillation (IPS - the scintillation of compact radio sources due to density variations in the solar wind) enable the velocity of the solar wind to be determined, and its bulk density to be estimated,…

Solar and Stellar Astrophysics · Physics 2022-10-06 R. A. Fallows , K. Iwai , B. V. Jackson , P. Zhang , M. M. Bisi , P. Zucca

We show the results of our analysis of the pulse broadening phenomenon in 25 pulsars at several frequencies using the data gathered with GMRT and Effelsberg radiotelescopes. Twenty two of these pulsars were not studied in that regard before…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Wojciech Lewandowski , Marta Dembska , Jaroslaw Kijak , Magdalena Kowalinska
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