Related papers: Deducing Electron Properties From Hard X-Ray Obser…
X-ray polarimetry is a fine tool to probe the accretion geometry and physical processes operating in the proximity of compact objects, black holes and neutron stars. Recent discoveries made by the Imaging X-ray Polarimetry Explorer put our…
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…
Solar flares are sudden energy release events in the solar corona, resulting from magnetic reconnection, that accelerates particles and heats the ambient plasma. During a flare, there are often multiple, temporally and spatially separated…
We investigate the X-ray and UV emission detected by RHESSI and TRACE in the context of a solar flare on the 16th November 2002 with the goal of better understanding the evolution of the flare. We analysed the characteristics of the X-ray…
Radiative polarization of electrons and positrons through the Sokolov-Ternov effect is important for applications in high-energy physics. Radiative spin-polarization is a manifestation of quantum radiation reaction affecting the…
A deep understanding of molecular photo-transformations is challenging because of the complex interaction between the configurations of electrons and nuclei. An initial optical excitation dissipates energy into electronic and structural…
The angular distribution of the emitted electrons, following the two-photon ionization of the hydrogen-like ions, is studied within the framework of second order perturbation theory and the Dirac equation. Using a density matrix approach,…
Free-electron laser hard X-ray light sources can provide high fluence, femtosecond pulses, enabling the time-resolved probing of structural dynamics and elementary relaxation processes in molecules. Traditional X-ray elastic scattering from…
Gamma-rays and neutrons are the only sources of information on energetic ions present during solar flares and on properties of these ions when they interact in the solar atmosphere. The production of {\gamma}-rays and neutrons results from…
Understanding nonthermal particle generation, transport, and escape in solar flares requires detailed quantification of the particle evolution in the realistic 3D domain where the flare takes place. Rather surprisingly, apart of standard…
Based on the drift-kinetic theory, we develop a model for particle acceleration and transport in solar flares. The model describes the evolution of the particle distribution function by means of a numerical simulation of the drift-kinetic…
Magnetars are believed to host the strongest magnetic fields in the present universe ($B\gtrsim10^{14}$ G) and the study of their persistent emission in the X-ray band offers an unprecendented opportunity to gain insight into physical…
We demonstrate that the angular distribution of electrons knocked out from an atom by a fast charge particle is determined not only by dipole but also by quadrupole transitions, the contribution of which can be considerably enhanced as…
The core theme of X-ray crystallography is reconstructing the electron density distribution of crystals under the constraints of observed diffraction data. Nevertheless, the reconstruction of electron density distribution by straightforward…
Aims. The H-alpha emission of solar flare kernels and associated hard X-ray (HXR) emission often show similar time variations but their light curves are shifted in time by energy transfer mechanisms. We searched for fast radiative response…
Particle acceleration mechanisms in supermassive black hole jets, such as shock acceleration, magnetic reconnection, and turbulence, are expected to have observable signatures in the multi-wavelength polarization properties of blazars. The…
Radiation emitted by unpolarized high-energy electrons penetrating crystals may be linearly polarized. This occurs when the particle velocity makes an angle, with respect to some major crystal axis, being sufficiently larger than the…
Understanding the relationship among different emission components plays an essential role in the study of particle acceleration and energy conversion in solar flares. In flares where gradual and impulsive emission components can be readily…
The toolbox for imaging molecules is well-equipped today. Some techniques visualize the geometrical structure, others the electron density or electron orbitals. Molecules are many-body systems for which the correlation between the…
Short-pulse intense lasers have the potential to model extreme astrophysical environments in laboratories. Although there are diagnostics for energetic electrons and ions resulting from laser-plasma interactions, the diagnostics to measure…