62 citations · 624 across the 31 of their papers we have counts for
31 papers
Magnetohydrodynamic turbulence and the associated spatial diffusion tensor of cosmic rays in dynamical galactic halos
J. Kleimann, H. Fichtner, M. Stein +3
A detailed understanding of cosmic-ray transport in galactic halos is essential for explaining various observations, such as the radio continuum measurements of synchrotron radiati…
CHANG-ES XXXIV: Magnetic Field Structure in Edge-On Galaxies Characterising large-scale magnetic fields in galactic halos
M. Stein, J. Kleimann, B. Adebahr +12
Understanding galactic magnetic fields is essential for interpreting feedback processes in galaxies. Despite their importance, the exact structure of these fields, particularly in…
Modeling the astrosphere of LHS~1140
K. Scherer, K. Herbst, N. E. Engelbrecht +3
The cosmic ray (CR) flux, as well as the hydrogen flux into the atmosphere of an exoplanet, can change the composition of the atmosphere. Here, we present the CR and hydrogen flux…
Turbulence in the outer heliosphere
Federico Fraternale, Laxman Adhikari, Horst Fichtner +9
The solar wind (SW) and local interstellar medium (LISM) are turbulent media. Their interaction is governed by complex physical processes and creates heliospheric regions with sign…
An exact analytical solution for the weakly magnetized flow around an axially symmetric paraboloid, with application to magnetosphere models
Jens Kleimann, Christian Röken
Rotationally symmetric bodies with longitudinal cross sections of parabolic shape are frequently used to model astrophysical objects, such as magnetospheres and other blunt objects…
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…
Simulating observable structures due to a perturbed interstellar medium in front of astrospheric bow shocks in 3D MHD
Lennart R. Baalmann, Klaus Scherer, Jens Kleimann +3
Context. While the shapes of many observed bow shocks can be reproduced by simple astrosphere models, more elaborate approaches have recently been used to explain differing observa…
On the Generation of Compressible Mirror-mode Fluctuations in the Inner Heliosheath
Horst Fichtner, Jens Kleimann, Peter H. Yoon +3
Measurements made with the Voyager 1 spacecraft indicate that significant levels of compressive fluctuations exist in the inner heliosheath. Some studies have already been performe…
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…
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…
Cosmic-ray propagation around the Sun: investigating the influence of the solar magnetic field on the cosmic-ray Sun shadow
Julia Becker Tjus, Paolo Desiati, Niklas Döpper +4
The cosmic-ray Sun shadow, which is caused by high-energy charged cosmic rays being blocked and deflected by the Sun and its magnetic field, has been observed by various experiment…
Solenoidal Improvements for the JF12 Galactic Magnetic Field Model
Jens Kleimann, Timo Schorlepp, Lukas Merten +1
The popular JF12 analytic model by Jansson & Farrar provides a quantitative description of the Galaxy's large-scale magnetic field, which is widely used in various astrophysical ap…
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…
The CRONOS Code for Astrophysical Magnetohydrodynamics
R. Kissmann, J. Kleimann, B. L. Krebl +1
We describe the magnetohydrodynamics (MHD) code CRONOS, which has been used in astrophysics and space physics studies in recent years. CRONOS has been designed to be easily adaptab…
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…
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…
Cosmic rays in astrospheres
Klaus Scherer, Ausgusts van der Schyff, Dominik Bomans +7
Cosmic rays passing through large astrospheres can be efficiently cooled inside these "cavities" in the interstellar medium. Moreover, the energy spectra of these energetic particl…
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…