82 citations · 1.3k across the 57 of their papers we have counts for
28 papers · 1 filter
On the properties of 0.11 keV to 344 MeV ion spectra in the inner heliosheath using regularized -distributions
Klaus Scherer, Kostas Dialynas, Horst Fichtner +2
The shape of the ion energy spectra plays a critical role toward determining the ion energetics, the acceleration mechanisms and the possible sources of different plasma and suprat…
Revisiting the Ulysses electron data with a triple fit of velocity distributions
Klaus Scherer, Edin Husidic, Marian Lazar +1
Given their uniqueness, the Ulysses data can still provide us with valuable new clues about the properties of plasma populations in the solar wind, and, especially, about their var…
Modelling O-star astrospheres with different relative speeds between the ISM and the star: 2D and 3D MHD model comparison
L. R. Baalmann, K. Scherer, J. Kleimann +3
Context. State of the art simulations of astrospheres are modelled using three-dimensional (3D) magnetohydrodynamics (MHD). An astrospheric interaction of a stellar wind (SW) with…
An Exact, Time-dependent Analytical Solution for the Magnetic Field in the Inner Heliosheath
Christian Röken, Jens Kleimann, Horst Fichtner
We derive an exact, time-dependent analytical magnetic field solution for the inner heliosheath, which satisfies both the induction equation of ideal magnetohydrodynamics in the li…
Transport coefficients enhanced by suprathermal particles in nonequilibrium heliospheric plasmas
Edin Husidic, Marian Lazar, Horst Fichtner +2
In heliospheric plasmas the transport of energy and particles is governed by various fluxes (e.g., heat flux) triggered by different forces, electromagnetic fields, and gradients i…
Generalized anisotropic -cookbook: 2D fitting of Ulysses electron data
Klaus Scherer, Edin Husidic, Marian Lazar +1
Observations in space plasmas reveal particle velocity distributions out of thermal equilibrium, with anisotropies (e.g., parallel drifts or/and different temperatures, $T_\paralle…
The -cookbook: a novel generalizing approach to unify -like distributions for plasma particle modeling
Klaus Scherer, Edin Husidic, Marian Lazar +1
In the literature different so-called -distribution functions are discussed to fit and model the velocity (or energy) distributions of solar wind species, pickup ions or magneto…
On the Diversity of M-Star Astrospheres and the Role of Galactic Cosmic Rays Within
Konstantin Herbst, Klaus Scherer, Stefan E. S. Ferreira +7
With upcoming missions such as the James Webb Space Telescope (JWST), the European Extremely Large Telescope (ELT), and the Atmospheric Remote-sensing Infrared Exoplanet Large-surv…
A new class of discontinuous solar wind solutions
Bidzina M. Shergelashvili, Velentin N. Melnik, Grigol Dididze +6
A new class of one-dimensional solar wind models is developed within the general polytropic, single-fluid hydrodynamic framework. The particular case of quasi-adiabatic radial expa…
MHD-shock structures of astrospheres: Cephei-like astrospheres
K. Scherer, L. R. Baalmann, H. Fichtner +5
The interpretation of recent observations of bow shocks around O-stars and the creation of corresponding models require a detailed understanding of the associated (magneto-)hydrody…
Skymaps of observables of three-dimensional MHD astrosphere models
L. R. Baalmann, K. Scherer, H. Fichtner +3
Three-dimensional models of astrospheres have recently become of interest. However, comparisons between these models and observations are non-trivial because of the two-dimensional…
An empirical model of Energetic Neutral Atom imaging of the heliosphere and its implications for future heliospheric missions at great heliocentric distances
Andre Galli, Peter Wurz, Horst Fichtner +2
Several concepts for heliospheric missions operating at heliocentric distances far beyond Earth orbit are currently investigated by the scientific community. The mission concept of…
The interaction of multiple stellar winds in stellar clusters: potential flow
Klaus Scherer, Alexander Noack, Jens Kleimann +2
While several studies have investigated large-scale cluster winds resulting from an intra-cluster interaction of multiple stellar winds, as yet they have not provided details of th…
On Aspects Pertaining to the Perpendicular Diffusion of Solar Energetic Particles
R. D. Strauss, H. Fichtner
The multitude of recent multi-point spacecraft observations of solar energetic particle (SEP) events have made it possible to study the longitudinal distribution of SEPs in great d…
An Improved Analytical Model of the Local Interstellar Magnetic Field: The Extension to Compressibility
J. Kleimann, C. Röken, H. Fichtner
A previously published analytical magnetohydrodynamic model for the local interstellar magnetic field in the vicinity of the heliopause (Röken et al. 2015) is extended from incompr…
Generalized multi-polytropic Rankine-Hugoniot relations and the entropy condition
Klaus Scherer, Horst Fichtner, Hans Jörg Fahr +2
The study aims at a derivation of generalized \RH relations, especially that for the entropy, for the case of different upstream/downstream polytropic indices and their implication…
A generalized two-component model of solar wind turbulence and ab initio diffusion mean free paths and drift lengthscales of cosmic rays
Tobias Wiengarten, Sean Oughton, Eugene Engelbrecht +3
We extend a two-component model for the evolution of fluctuations in the solar wind plasma so that it is fully three-dimensional (3D) and also coupled self-consistently to the larg…
Shock structures of astrospheres
Klaus Scherer, Horst Fichtner, Jens Kleimann +3
The interaction between a supersonic stellar wind and a (super-)sonic interstellar wind has recently been viewed with new interest. We here first give an overview of the modeling,…
Toward more realistic analytic models of the heliotail: Incorporating magnetic flattening via distortion flows
Jens Kleimann, Christian Röken, Horst Fichtner +1
Both physical arguments and simulations of the global heliosphere indicate that the tailward heliopause is flattened considerably in the direction perpendicular to both the incomin…
On the Geometry of the IBEX Ribbon
Adama Sylla, Horst Fichtner
The Energetic Neutral Atom (ENA) full-sky maps obtained with the Interstellar Boundary Explorer (IBEX) show an unexpected bright narrow band of increased intensity. This so-called…
Parameter estimation of superdiffusive motion of energetic particles upstream of heliospheric shocks
Silvia Perri, Gaetano Zimbardo, Frederic Effenberger +1
In-situ spacecraft observations recently suggested that the transport of energetic particles accelerated at heliospheric shocks can be anomalous, i.e. the mean square displacement…
Implementing turbulence transport in the CRONOS framework and application to the propagation of CMEs
Tobias Wiengarten, Horst Fichtner, Jens Kleimann +1
We present the implementation of turbulence transport equations in addition to the Reynolds-averaged MHD equations within the Cronos framework. The model is validated by comparison…
An exact analytical solution for the interstellar magnetic field in the vicinity of the heliosphere
Christian Röken, Jens Kleimann, Horst Fichtner
An analytical representation of the interstellar magnetic field in the vicinity of the heliosphere is derived. The three-dimensional field structure close to the heliopause is calc…
Cosmic Ray Transport in Heliospheric Magnetic Structures: I. Modeling Background Solar Wind Using the CRONOS MHD Code
Tobias Wiengarten, Jens Kleimann, Horst Fichtner +4
The transport of energetic particles such as Cosmic Rays is governed by the properties of the plasma being traversed. While these properties are rather poorly known for galactic an…