A5065357584- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Dust and Plasma Wave Phenomena
- Geophysics and Gravity Measurements
- Dark Matter and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Geomagnetism and Paleomagnetism Studies
- Atmospheric Ozone and Climate
- Cosmology and Gravitation Theories
- Statistical Mechanics and Entropy
- Magnetic confinement fusion research
- Planetary Science and Exploration
- Solar Radiation and Photovoltaics
- Fractional Differential Equations Solutions
- Fluid Dynamics and Turbulent Flows
- Gas Dynamics and Kinetic Theory
- Spacecraft and Cryogenic Technologies
- Advanced Battery Technologies Research
- Earthquake Detection and Analysis
- Laser-induced spectroscopy and plasma
- Particle accelerators and beam dynamics
Ruhr University Bochum
2015-2024
University of Wisconsin–Madison
2021-2022
Institut de Recherche sur les Lois Fondamentales de l'Univers
2022
Université Paris-Saclay
2022
Universität Innsbruck
2022
Dutch Institute for Fundamental Energy Research
2022
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2022
Eindhoven University of Technology
2022
CEA Paris-Saclay
2022
Mansoura University
2018
The Sun moves through the local interstellar medium, continuously emitting ionized, supersonic solar wind plasma and carving out a cavity in space called heliosphere. recently launched Interstellar Boundary Explorer (IBEX) spacecraft has completed its first all-sky maps of interaction at edge heliosphere by imaging energetic neutral atoms (ENAs) emanating from this region. We found bright ribbon ENA emission, unpredicted prior models or theories, that may be ordered magnetic field...
The Interstellar Boundary Explorer (IBEX) is a small explorer mission that launched on 19 October 2008 with the sole, focused science objective to discover global interaction between solar wind and interstellar medium. IBEX designed achieve this by answering four fundamental questions: (1) What strength structure of termination shock, (2) How are energetic protons accelerated at (3) properties flow beyond shock in heliotail, (4) does interact heliosphere heliopause? answers these questions...
What's Happening in the Heliosphere The influence of Sun is felt well beyond orbits planets. solar wind a stream charged particles emanating from that carves bubble interstellar space known as heliosphere and shrouds entire system. edge heliosphere, region where interacts with space, largely unexplored. Voyager 1 2 crossed this boundary 2004 2007, respectively, providing detailed but only localized information. In issue (see cover), McComas et al. (p. 959 , published online 15 October),...
Context. The generally accepted representation of κ-distributions in space plasma physics allows for two different alternatives, namely assuming either the temperature or thermal velocity to be κ-independent.
Cosmogenic Isotopes are produced in the Earth's atmosphere due to interaction of galactic cosmic rays with nuclei atmospheric atoms. Among others, 10 Be concentration ice cores depends on ray flux outside magnetosphere and provides therefore a unique tool investigate solar modulation over very long time periods. In this study we importance different local interstellar proton spectra often used literature obtained magnetosphere. order parameterize heliospheric apply force‐field solution using...
Context. Suprathermal populations are ubiquitous in the solar wind, indicating plasma states out of thermal equilibrium, and an excess free energy expected to enhance kinetic instabilities. However, recent endeavors disclose effects these on electromagnetic instabilities driven by temperature anisotropy do not confirm this expectation, but mainly show that inhibited suprathermals.
Two of the paradigms in modeling transport galactic cosmic rays are that modulation boundary is heliopause and local interstellar spectra identical to ray spectra. Here we demonstrate proton spectrum already modulated due an altered diffusion outer heliosheath as a consequence heliospheric "obstacle" flow. The main effect however adiabatic energy losses during "confinement time" inside heliosphere.
The multitude of recent multi-point spacecraft observations solar energetic particle (SEP) events has made it possible to study the longitudinal distribution SEPs in great detail. SEPs, even those accelerated during impulsive events, show a much wider than expected extent, bringing into question processes responsible for their transport perpendicular local magnetic field. In this paper, we examine some aspects by including diffusion numerical SEP model that simulates propagation impulsively...
For various plasma applications the so-called (non-relativistic) κ -distribution is widely used to reproduce and interpret suprathermal particle populations exhibiting a power-law distribution in velocity or energy. Despite its reputation standard as concept still disputable, mainly due moments M l which make macroscopic characterization possible, but whose existence restricted only low orders . In fact, definition of itself conditioned by moment order = 2 ( i.e. , kinetic temperature)...
Context. Recent studies on Kappa distribution functions invoked in space plasma applications have emphasized two alternative approaches which may assume the temperature parameter either dependent or independent of power-index $\kappa$. Each them can obtain justification different scenarios involving Kappa-distributed plasmas, but direct evidences supporting any these alternatives with measurements from laboratory natural plasmas are not available yet. Aims. This paper aims to provide more...
Understanding the configuration of galactic magnetic fields is essential for interpreting feedback processes in galaxies. Despite their importance, exact structure these fields, particularly halos, remains unclear. Accurate descriptions are crucial understanding interaction between star formation and halo magnetisation. By systematically analysing polarisation patterns halos nearby galaxies, we aim to deepen interplay processes. Here, focus on process magnetising halo. Furthermore, provide...
The heliospheric modulation of galactic and Jovian electrons is studied using a fully three‐dimensional, steady state model based on Parker's transport equation including the source. low‐energy handy tool to establish construct suitable diffusion tensor assure compatibility between computations observations from Ulysses spacecraft. This because electron responds directly energy dependence coefficients below ∼500 MeV in contrast protons which experience large adiabatic losses this energy....
During the latest Ulysses out-of-ecliptic orbit solar wind density, pressure, and magnetic field strength have been lowest ever observed in history of space exploration. Since cosmic ray particles respond to heliospheric expanding its turbulence, weak as well low plasma density pressure are expected cause smallest modulation since 1970s. In contrast this expectation, galactic (GCR) proton flux at 2.5 GV measured by 2008 does not exceed one 1990s significantly, while GCR electron intensity...
Results from a newly developed hybrid cosmic ray (CR) modulation model are presented. In this approach, the transport of CRs is computed by incorporating plasma flow magnetohydrodynamic for heliospheric environment, resulting in representative CR transport. The applied to beyond heliopause (HP) and we show that (1) persists HP, so it unlikely Voyager spacecraft will measure pristine local interstellar spectra galactic when crossing HP. (2) outer heliosheath could maintain solar-cycle-related...
We extend a two-component model for the evolution of fluctuations in solar wind plasma so that it is fully three-dimensional (3D) and also coupled self-consistently to large-scale magnetohydrodynamic (MHD) equations describing background wind. The two classes considered are high-frequency parallel-propagating wave-like piece low-frequency quasi-two-dimensional component. For both components, nonlinear dynamics dominanted by quasi-perpendicular spectral cascades energy. Driving fluctuations,...
Galactic transport models for cosmic rays involve the diffusive motion of these particles in interstellar medium. Due to large-scale structured galactic magnetic field this diffusion is anisotropic with respect local direction. We included effect along continuous loss processes a quantitative model propagation ray protons which based on stochastic differential equations. calculated energy spectra at different positions Sun's orbit and compared them isotropic case. The results show that...
The propagation of charged cosmic rays through the Galactic environment influences all aspects observation at Earth. Energy spectrum, composition and arrival directions are changed due to deflections in magnetic fields interactions with interstellar medium. Today transport is simulated different simulation methods either based on solution a equation (multi-particle picture) or an motion (single-particle picture). We developed new module for publicly available software CRPropa 3.1, where we...
This review paper compiles recent results obtained by the present group of authors describing effects suprathermal populations in space plasmas (up to a few keVs) on temperature anisotropy instabilities. Of particular interest are electromagnetic cyclotron and firehose excitations, which play major role limiting anisotropy, resulting, for instance, from adiabatic expansion solar wind. Relying rigorous modeling interpretation observed velocity distributions, both theoretical models numerical...
Abstract Energetic particles represent an important component of the plasma in heliosphere. They range from accelerated at impulsive events solar corona and large scale structures interplanetary medium, to anomalous cosmic rays boundaries In-situ satellite observations, numerical simulations theoretical models have advanced, often a cooperative way, our knowledge on acceleration processes involved. In this paper we review recent developments particle acceleration, with major emphasis shock...
The solar wind (SW) and local interstellar medium (LISM) are turbulent media. Their interaction is governed by complex physical processes creates heliospheric regions with significantly different properties in terms of particle populations, bulk flow turbulence. Our knowledge the turbulence \nature dynamics mostly relies on near-Earth near-Sun observations, has been increasingly improving recent years due to availability a wealth space missions, including multi-spacecraft missions. In...
Often invoked to explain solar radio bursts is the standard model of plasma systems with electron beams and their Langmuir wave excitations, although parameterization favorable these excitations very narrow. Here we use first-principle kinetic theory numerical simulations prove a direct as well an indirect involvement electrostatic electron-beam waves in generation emissions. At first sight, primary frequency below do not conform nonlinear decays model. However, at origin are denser or...
Space plasmas in various astrophysical setups can often be both very hot and dilute, making them highly susceptible to waves fluctuations, which are generally self-generated maintained by kinetic instabilities. In this sense, we have situ observational evidence from the solar wind planetary environments, reveal not only wave fluctuations at scales of electrons protons but also non-equilibrium distributions particle velocities. This paper reports on progress made achieving a consistent...
In the last few years it has been demonstrated, both by data analysis and numerical simulations, that transport of energetic particles in presence magnetic turbulence can be superdiffusive rather than normal diffusive (Gaussian). The term ‘superdiffusive’ refers to mean square displacement particle positions growing superlinearly with time, as compared linear growth. so-called anomalous transport, which general comprises subdiffusion superdiffusion, gained attention during two decades many...