Related papers: Sunspot seismic halos generated by fast MHD wave r…
Radio observations discovered large scale non thermal sources in the central Mpc regions of dynamically disturbed galaxy clusters (radio halos). The morphological and spectral properties of these sources suggest that the emitting electrons…
The WMAP haze is an excess in the 22 to 93 GHz frequency bands of WMAP extending about 10 degrees from the galactic center. We show that synchrotron emission from electron-positron pairs injected into the interstellar medium by the galactic…
One of the mechanisms proposed for heating the corona above solar active regions is the damping of magnetohydrodynamic (MHD) waves. Continuing on previous work, we provide observational evidence for the existence of high-frequency MHD waves…
Absorbtion of Alfven waves is considered to be the main mechanism of heating in the solar corona. It is concluded that the sharp increase of the plasma temperature by two orders of magnitude is related to a self-induced opacity with respect…
Starburst galaxies are undergoing intense episodes of star formation. In these galaxies, gas is ejected into the surrounding environment through winds created by the effect of hot stars and supernova explosions. When interacting with the…
Transverse MHD waves permeate the solar atmosphere and are a candidate for coronal heating. However, the origin of these waves is still unclear. In this work, we analyse coordinated observations from \textit{Hinode}/SOT and \textit{IRIS} of…
Oscillations in coronal loops are usually interpreted in terms of uncoupled magnetohydrodynamic (MHD) waves. Examples of these waves are standing transverse motions, interpreted as the kink MHD modes, and propagating slow modes, commonly…
In the solar wind electron velocity distributions reveal two counter-moving populations which may induce electromagnetic (EM) beaming instabilities known as heat flux instabilities. Depending on plasma parameters two distinct branches of…
We present a detailed quantitative description of the recently proposed "slingshot effect" [Fiore, Fedele, De angelis 2014]. Namely, we determine a broad range of conditions under which the impact of a very short and intense laser pulse…
The use of acoustic holography in the high-frequency $p$-mode spectrum can resolve the source distributions of enhanced acoustic emissions within halo structures surrounding active regions. In doing so, statistical methods can then be…
The goal of this research is to investigate how magnetic field affects the dynamics of granular convection and excitation of solar oscillations by means of realistic numerical simulations. We have used a 3D, compressible, non-linear…
We introduce a physically-motivated model of the matter power spectrum, based on the halo model and perturbation theory. This model achieves 1\% accuracy on all $k-$scales between $k=0.02h\,\mathrm{Mpc}^{-1}$ to $k=1h\,\mathrm{Mpc}^{-1}$.…
Small-scale, cyclic, transverse motions of plasma threads are usually seen in solar prominences, which are often interpreted as magnetohydrodynamic (MHD) waves. Here, we observed small-scale decayless transverse oscillations in a quiescent…
Pulsar halos are extended gamma-ray structures generated by electrons and positrons escaping from pulsar wind nebulae (PWNe), considered a new class of gamma-ray sources. They are ideal indicators for cosmic-ray propagation in localized…
Solar eruptions are the leading driver of space weather, and it is vital for space weather forecast to understand in what conditions the solar eruptions can be produced and how they are initiated. The rotation of sunspots around their…
Observational aspects of solar flares relevant to the acceleration process of electrons and protons are reviewed and it is shown that most of these observations can be explained by the interaction with flare plasma of a power law energy…
Although high-resolution N-body simulations make robust empirical predictions for the density distribution within cold dark matter halos, these studies have yielded little physical insight into the origins of the distribution. We…
We present a model of magnetohydrodynamic (MHD) turbulence in the extended solar corona that contains the effects of collisionless dissipation and anisotropic particle heating. Measurements made by UVCS/SOHO have revived interest in the…
A phenomenological relationship between oscillations in a sunspot and quasi-periodic pulsations in flaring energy releases at an active region above the sunspot, is established. The analysis of the microwave emission recorded by the…
We discuss a possible mechanism for heating the solar atmosphere by the ensemble of thermal waves, generated by the photospheric dynamo and propagating upwards with increasing magnitudes. These waves are self-sustained and amplified due to…