Related papers: Determination of Electromagnetic Source Direction …
Radio photons interact with anisotropic density fluctuations in the heliosphere, which can alter their trajectory and influence properties deduced from observations. This is particularly evident in solar radio observations, where…
We have analysed radio type IV bursts in the interplanetary (IP) space at decameter-hectometer (DH) wavelengths, to find out their source origin and a reason for the observed directivity. We used radio dynamic spectra from the instruments…
Electromagnetic wave scattering off density inhomogeneities in the solar corona is an important process which determines both the apparent source size and the time profile of radio bursts observed at 1 AU. Here we model the scattering…
I analyse and numerically evaluate the radiation field generated by an experimentally realized embodiment of an electric polarization current whose rotating distribution pattern moves with linear speeds exceeding the speed of light in…
Astrophysical radio sources are embedded in turbulent magnetised environments. In the 1 MHz sky, solar radio bursts are the brightest sources, produced by electrons travelling along magnetic field lines from the Sun through the heliosphere.…
We present a polarization catalog of 533 extragalactic radio sources with 2.3 GHz total intensity above 420 mJy from the S-band Polarization All Sky Survey, S-PASS, with corresponding 1.4 GHz polarization information from the NRAO VLA Sky…
The study of impulsive astrophysical radio emission makes it possible to probe the intervening plasma between the emission source and the Earth. In cold electron-ion plasmas, the circular propagating wave modes primarily alter the linear…
We report multi-wavelength observations of four solar flares on 2014 July 07. We firstly select these flares according to the soft X-ray (SXR) and extreme ultraviolet (EUV) emissions recorded by the Extreme Ultraviolet Variability…
Polarization measurements at low radio frequencies allow detection of small Faraday rotation measures caused by regular magnetic fields in galaxies and in the foreground of the Milky Way. The galaxy M31 was observed in two overlapping…
The inverse electromagnetic source scattering problem from multi-frequency sparse electric far field patterns is considered. The underlying source is a combination of electric dipoles and magnetic dipoles. We show that the locations and the…
Linearly polarized emission is described, in general, in terms of the Stokes parameters $Q$ and $U$, from which the polarization intensity and polarization angle can be determined. Although the polarization intensity and polarization angle…
One of the most commonly observed solar radio sources in the metric and decametric wavelengths is the solar noise storm. These are generally associated with active regions and are believed to be powered by the plasma emission mechanism.…
Super-sensitive observations of bright pulsars by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) have revealed weak radio emission continuously emerged in the rotation phases between the main pulse and interpulse of an…
We present results from a combined radio polarization and emission line study of five type 2 quasars at $z<0.2$ with the Karl G. Jansky Very Large Array (VLA) B-array at 5 GHz and Hubble Space Telescope (HST) [O III] observations. These…
Type III radio bursts are radio emissions associated with solar flares. They are considered to be caused by electron beams traveling from the solar corona to the solar wind. Magnetic reconnection is a possible accelerator of electron beams…
We discuss the localization of radiation sources whose number and other relevant parameters are not known in advance. The data collection is ensured by an autonomous mobile robot that performs a survey in a defined region of interest…
Solar radio bursts (SRBs), are emitted by electrons propagating through the corona and interplanetary space. Tracking such bursts is key to understanding the properties of accelerated electrons and radio wave propagation as well as the…
Context. The origin of coronal type-II radio bursts and of their band-splitting are still not fully understood. Aims. To make progress in solving this problem on the basis of one extremely well observed solar eruptive event. Methods. The…
Source imaging of solar radio bursts can be used to track energetic electrons and associated magnetic structures. Here we present a combined analysis of data at different wavelengths for an eruption associated with a moving type-IV (t-IVm)…
Simultaneous $\gamma$-ray measurements of gamma-ray burst (GRB) spectra and polarization offer a unique way to determine the underlying emission mechanism(s) in these objects as well as probing the particle acceleration mechanism(s) that…