Now showing items 1-19 of 19

    • Aspects of the time-dependent modulation of galactic cosmic rays throughout a three-dimensional heliosphere 

      Mohlolo, Selwana Timothy (North-West University (South Africa), 2021)
      A dominant feature in the heliosphere is the heliospheric current sheet, separating regions of opposite polarity of the heliospheric magnetic field. This structure is dependent on solar activity through the tilt angle, ...
    • Modelling of cosmic ray modulation in the heliosphere by stochastic processes 

      Strauss, Roelf du Toit (North-West University, 2013)
      The transport of cosmic rays in the heliosphere is studied by making use of a newly developed modulation model. This model employes stochastic differential equations to numerically solve the relevant transport equation, ...
    • Modelling of galactic and jovian electrons in the heliosphere 

      Moeketsi, Daniel Mojalefa (North-West University, 2004)
      A three-dimensional (3D) steady-state electron modulation model based on Parker (1965) transport equation is applied to study the modelling of – 7 MeV galactic and Jovian electrons in the inner heliosphere. The latter ...
    • Modelling of galactic cosmic ray electrons in the heliosphere 

      Nndanganeni, Rendani Rejoyce (North-West University, 2012)
      The Voyager 1 spacecraft is now about 25 AU beyond the heliospheric termination shock and soon it should encounter the outer boundary of the heliosphere, the heliopause. This is set to be at 120 AU in the modulation model ...
    • Modelling of the heliosphere and cosmic ray transport 

      Snyman, Jasper Lodewyk (North-West University, 2007)
      A two dimensional hydrodynamic model describing the solar wind interaction with the local interstellar medium, which surrounds the solar system, is used to study the heliosphere both as a steady-state- and dynamic structure. ...
    • Modelling the evolution of pulsar wind nebulae 

      Vorster, Michael Johannes (2014)
      This study focusses on modelling important aspects of the evolution of pulsar wind nebulae using two different approaches. The first uses a hydrodynamic model to simulate the morphological evolution of a spherically-symmetric ...
    • The modulation of galactic cosmic rays over a solar cycle 

      Mohlolo, Selwana Timothy (North-West University (South Africa), 2016)
      This work studied the modulation of galactic cosmic rays in the heliosphere by using a well-established, time dependent numerical modulation model to calculate cosmic ray transport inside the heliosphere over a solar ...
    • Novel radar and optical observations of black auroras in the upper atmosphere 

      Nel, Amoré Elsje (North-West University (South Africa), 2019)
      Black auroras show a significant reduction in optical brightness, i.e. reduced flux of particle precipitation, compared to the surrounding diffuse aurora. This phenomenon also exhibits lower mean energy than the surrounding ...
    • Numerical modeling of the evolution of stellar wind cavities and supernova remnants 

      Van der Schyff, Augusts Eric (North-West University, Potchefstroom Campus, 2016)
      An astrosphere is a low density cavity that results from an outflowing supersonic wind. Of particular interest in this study is the effect of radiative cooling on the computed evolution of astrospheres created by O and ...
    • Numerical modelling of Astrospheres 

      Light, J. (North-West University (South Africa)North-West University, 2020)
      A stellar wind creates a cavity in the interstellar medium, which is known as an astrophere. In this work, radiative cooling is included in a standard 2D magneto-hydrodynamic numerical model to simulate the evolution of ...
    • Numerical modelling of stellar winds for supernova progenitors 

      Van den Heever, Stefanus Petrus (North-West University, 2011)
      A two-dimensional hydrodynamic numerical model is extended and applied to simulate the interaction between stellar winds and the interstellar medium (ISM). In particular, the stellar wind evolution of O- and B-type stars ...
    • The numerical simulation of astrospheric evolution in different interstellar environments 

      Marais, Andrea (North-West University (South Africa), 2023)
      The interaction between the interstellar medium (ISM) and a stellar wind leads to the formation of an astrosphere. In this study, the evolution of astrospheres is simulated with a two-dimensional spherical hydrodynamic ...
    • On the development and applications of a three–dimensional ab initio cosmic–ray modulation model 

      Engelbrecht, Nicholas Eugéne (North-West University, 2012)
      A proper understanding of the effects of turbulence on the diffusion and drift of cosmic-rays in the heliosphere is imperative for a better understanding of cosmic-ray modulation. This study presents an ab initio model ...
    • Particle acceleration at travelling shocks in the heliosphere 

      Prinsloo, Phillip Lourens (North-West University (South Africa), 2020)
      The acceleration of energetic protons from the solar wind (SW) distribution by traveling interplanetary shocks is investigated. The SW velocity distribution is represented using kappa functions, which are transformed in ...
    • 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 study of cosmic ray anisotropies in the heliosphere 

      Nkosi, Godfrey Sibusiso (North-West University, 2006)
      The three-dimensional (3D) steady-state electron modulation model of Ferreira (2002), based on Parker (1965) transport equation, is used to study the modulation of the 7 MeV galactic and Jovian electron anisotropies in ...
    • A study of the time-dependent modulation of cosmic rays in the inner heliosphere 

      Magidimisha, Edwin (North-West University, 2010)
      A two-dimensional (2-D) time-dependent cosmic ray modulation model is used to calculate the modulation of cosmic-ray protons and electrons for 11-and 22-year modulation cycles using a compound approach to describe solar ...
    • A study of the time-dependent modulation of galactic cosmic rays in the heliosphere 

      Ndiitwani, Dzivhuluwani Christopher (North-West University, 2005)
      Time-dependent cosmic ray modulation in the heliosphere is studied by using a two-dimensional time dependent modulation model. To compute realistic cosmic ray modulation a compound approach is used, which combines the ...
    • Time–dependent modulation of cosmic rays in the outer heliosphere 

      Manuel, Rex (North-West University, 2013)
      The time-dependent modulation of galactic cosmic rays in the heliosphere is studied by computing intensities using a two-dimensional, time-dependent modulation model. The compound approach of Ferreira and Potgieter (2004), ...