Browsing by Author "Kopp, A."
Now showing items 1-11 of 11
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Comparative time-series analysis of MeV electron data by Ulysses and Pioneer 10/11 in the Jovian magnetosphere
Dunzlaff, P.; Kopp, A.; Potgieter, M.S.; Heber, B. (Copernicus Publications, 2013)The dynamics of the Jovian magnetosphere is dominated by the planet’s fast rotation with a period of 10 h.Within the magnetosphere, this periodicity can in particular be seen in the temporal variation of the spectral index ... -
Glow-in-the-dark globular clusters: modelling their multiwavelength lanterns
Venter, C.; Büsching, I.; De Jager, O.C.; Kopp, A.; Clapson, A-C. (South African Institute of Physics, 2012)Globular clusters (GCs) are astronomical tapestries embroidered with an abundance of exotic stellar-type objects, including ancient metal-poor stars, planetary nebulae, white dwarfs (WDs), low-mass X-ray binaries (LMXRBs), ... -
Modeling the modulation of galactic and jovian electrons by stochastic processes
Strauss, R.D.; Potgieter, M.S.; Büsching, I.; Kopp, A. (IOP Publishing, 2011)We present a newly developed numerical modulation model to study the transport of galactic and Jovian electrons in the heliosphere. The model employs stochastic differential equations (SDEs) to solve the corresponding ... -
Modelling heliospheric current sheet drift in stochastic cosmic ray transport models
Strauss, R.D.; Potgieter, M.S.; Büsching, I.; Kopp, A. (Springer, 2012)Drifts are one of the major cosmic ray modulation mechanisms in the heliosphere. Three types of drifts occur in the background heliospheric magnetic field, namely curvature, gradient and current sheet drifts. The last ... -
Modulation of galactic cosmic ray protons and electrons during an unusual solar minimum
Heber, B.; Potgieter, M.S.; Ferreira, S.E.S.; Kopp, A.; Gieseler, J. (IOP Publishing, 2009)During the latest Ulysses out-of-ecliptic orbit the solar wind density, pressure, and magnetic field strength have been the lowest ever observed in the history of space exploration. Since cosmic ray particles respond to ... -
Multi-wavelength modeling of globular clusters: the millisecond pulsar scenario
Kopp, A.; Venter, C.; Büsching, I.; De Jager, O.C. (IOP Publishing, 2013)The potentially large number of millisecond pulsars (MSPs) in globular cluster (GC) cores makes these parent objects ideal laboratories for studying the collective properties of an ensemble of MSPs. Such a population is ... -
On the propagation times and energy losses of cosmic rays in the heliosphere
Strauss, R.D.; Potgieter, M.S.; Kopp, A.; Büsching, I. (American Geophysical Union, 2011)We present calculations of the propagation times and energy losses of cosmic rays as they are transported through the heliosphere. By calculating these quantities for a spatially 1D scenario, we benchmark our numerical ... -
A stochastic approach to galactic proton propagation: influence of the spiral arm structure
Kopp, A.; Büsching, I.; Potgieter, M.S.; Strauss, R.D. (Elsevier, 2014)A newly developed numerical code solving Fokker–Planck type transport equations in currently four dimensions (space plus momentum or energy) and time by means of stochastic differential equations (SDEs) is applied to the ... -
A stochastic approach to the modelling of cosmic rays in the heliosphere
Raath, Jan Louis (North-West University (South Africa), 2020)A spatially three-dimensional numerical modulation model based on solving a set of stochastic differential equations, corresponding to the Parker transport equation, is employed to study the galactic proton spectra measured ... -
A stochastic differential equation code for multidimensional Fokker-Planck type problems
Kopp, A.; Büsching, I.; Strauss, R.D.; Potgieter, M.S. (Elsevier, 2012)We present a newly developed numerical code that integrates Fokker–Planck type transport equations in four to six spatial dimensions (configuration plus momentum space) and time by means of stochastic differential equations. ... -
The effects of magnetic field modifications on the solar modulation of cosmic rays with a SDE-based model
Raath, J.L.; Potgieter, M.S.; Strauss, R.D.; Kopp, A. (Elsevier, 2016)A numerical model for the solar modulation of cosmic rays, based on the solution of a set of stochastic differential equations (SDEs), is used to illustrate the effects of modifying the heliospheric magnetic field, ...