相关论文: Scattering model of scintillation arcs in pulsar s…
Pulsar dynamic spectra sometimes show organised interference patterns; these patterns have been shown to have power spectra which often take the form of parabolic arcs, or sequences of inverted parabolic arclets whose apexes themselves…
Our theory relates the secondary spectrum, the 2D power spectrum of the radio dynamic spectrum, to the scattered pulsar image in a thin scattering screen geometry. Recently discovered parabolic arcs in secondary spectra are generic features…
We introduce a novel analysis technique for pulsar secondary spectra. The power spectrum of pulsar scintillation (referred to as the "secondary spectrum") shows differential delays and Doppler shifts due to interference from multi-path…
Radio waves propagating through the interstellar medium are influenced by variations in plasma density. For spatially localised plasma structures along the line of sight, time-delay Doppler analyses of pulsars often reveal scintillation…
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…
Context. Pulsars scintillate. Dynamic spectra show brightness variation of pulsars in the time and frequency domain. Secondary spectra demonstrate the distribution of fluctuation power in the dynamic spectra. Aims. Dynamic spectra strongly…
The parabolic arc phenomenon visible in the Fourier analysis of the scintillation spectra of pulsars provides a new method of investigating the small scale structure in the ionized interstellar medium (ISM). We report archival observations…
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…
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…
We have made high-resolution, high-sensitivity dynamic spectra of a sample of strong pulsars at 430 MHz with the Arecibo radiotelescope. For 4 pulsars we find faint but sharply delineated features in the secondary spectra. These are…
In this work we study variations in the parabolic scintillation arcs of the binary millisecond pulsar PSR J1643-1224 over five years using the Large European Array for Pulsars (LEAP). The 2D power spectrum of scintillation, called the…
Intensity scintillations of radio pulsars are known to originate from interference between waves scattered by the electron density irregularities of interstellar plasma, often leading to parabolic arcs in the two-dimensional power spectrum…
We observed the scintillation pattern of nine bright pulsars at 324 MHz and three at 1.68 GHz and analyzed the wavenumber spectrum which is related to electron density variations of the plasma turbulence of the interstellar medium. For all…
Extreme Scattering Events and pulsar secondary spectra have highlighted fundamental problems in our understanding of the dynamics of interstellar turbulence. We describe some of these problems in detail and present the theory behind the…
Scattering of resonant radiation in a dense two-level medium is studied theoretically with account for local field effects and renormalization of the resonance frequency. Intrinsic optical bistability is viewed as switching between…
We employ a scalar model to exemplify the use of contour deformations when solving Lorentz-invariant integral equations for scattering amplitudes. In particular, we calculate the onshell 2 -> 2 scattering amplitude for the scalar system.…
Pulsar scintillation allows a glimpse into small-scale plasma structures in the interstellar medium, if we can infer their properties from the scintillation pattern. With Very Long Baseline Interferometry and working in delay-delay rate…
Context. The spatially coherent multipath propagation of pulsar radiation leads to a temporal and spectral interference patterns called scintillation. It is caused by density variations in the ionized interstellar medium, which often take…
Interference of randomly scattered classical waves naturally leads to familiar speckle patterns, where the wave intensity follows an exponential distribution while the wave field itself is described by a circularly symmetric complex normal…
Using data from the Large European Array for Pulsars (LEAP), and the Effelsberg telescope, we study the scintillation parameters of the millisecond pulsar J0613-0200 over a 7 year timespan. The "secondary spectrum" -- the 2D power spectrum…