Lecturer: Andreas Ekenbäck (IRF) Date: 2008-09-26 10:00 Place: Aula
Numerical modelling of ENAs from stellar wind interactions
Andreas Ekenbäck
Swedish Institute of Space Physics
PhD defense.
The opponent is Dr Michael R. Collier (NASA/Goddard Space Flight Center, Greenbelt, Maryland, USA).
The grading committee is Professor Sandra C. Chapman (University of Warwick, UK), Professor Stefan Buehler (LTU), and Docent Hans Nilsson (IRF).
Numerical modeling of ENAs from stellar wind interactions, Andreas Ekenbäck, IRF Scientific Report 297, August 2008 (ISBN 978-91-977255-5-2) [PDF, 1 MB]Included papers
Abstract
Energetic neutral atoms (ENAs) are produced whenever a stellar wind encounters a neutral atmosphere. If a stellar wind proton comes sufficiently close to a neutral a charge-exchange reaction may take place, transforming the proton into an ENA. Unaffected by magnetic and electric fields, ENAs provide an opportunity for global imaging of stellar wind interactions.
This thesis presents methods and results of numerical modelling of stellar wind interactions. In particular it treats in depth production of ENAs at comets, Mars and the extrasolar planet HD 209458b.
Sufficiently accurate numerical models of stellar wind interactions require extensive computations. Parallel computing has therefore been used throughout the work, both for fluid and particle simulations of space plasmas. This thesis describes the use of a general simulation tool, providing parallel computing for space plasma simulations.
The thesis presents estimations of the magnitude and morphology of the ENA production at comets and HD 209458b. It compares the results obtained with observations and analyzes them in the light of ENA production at similar objects. Also, simulated ENA images for Mars were produced and compared to observations.
Created 2008-08-13 14:35:35 by Mats Holmström Last changed 2008-09-25 23:40:00 by Mats Holmström
