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1	Helioseismické inverze toků plazmatu a poruch rychlosti zvuku / Helioseismic inversions of plasma flows and sound-speed perturbations Korda, David January 2020 (has links) Local helioseismology consists of methods which study the propagation of the waves through the solar interior. The properties of the waves encode conditions in the plasma along their propagation trajectories. Local helioseismology allows us to learn about these conditions. The principal method utilised in this thesis is the time-distance local helioseismology. The time-distance method is based on measurements of travel times of the waves, hence it is sensitive especially to plasma flows and sound-speed perturbations, to which we focus. We utilised the inverse modelling, mainly using subtractive optimally localised averaging method with a minimisation of the cross-talk. This method was modified to allow for a simultaneous inversion of vector flows and sound-speed perturbation. This combination makes use of both the difference and the mean point-to-annulus averaging geometries of wave travel times in both the ridge and the phase-speed filtering approaches. The combined inversion provides us with more information about the inverted quantities. Moreover, the user can control the cross-talk and other important mathematical properties of the objects involved. The modified methodology was thoroughly tested. The main results may be summarised in five points. First, for successful inversions of the sound-speed...
2	Helioseismické inverze toků plazmatu a poruch rychlosti zvuku / Helioseismic inversions of plasma flows and sound-speed perturbations Korda, David January 2020 (has links) Local helioseismology consists of methods which study the propagation of the waves through the solar interior. The properties of the waves encode conditions in the plasma along their propagation trajectories. Local helioseismology allows us to learn about these conditions. The principal method utilised in this thesis is the time-distance local helioseismology. The time-distance method is based on measurements of travel times of the waves, hence it is sensitive especially to plasma flows and sound-speed perturbations, to which we focus. We utilised the inverse modelling, mainly using subtractive optimally localised averaging method with a minimisation of the cross-talk. This method was modified to allow for a simultaneous inversion of vector flows and sound-speed perturbation. This combination makes use of both the difference and the mean point-to-annulus averaging geometries of wave travel times in both the ridge and the phase-speed filtering approaches. The combined inversion provides us with more information about the inverted quantities. Moreover, the user can control the cross-talk and other important mathematical properties of the objects involved. The modified methodology was thoroughly tested. The main results may be summarised in five points. First, for successful inversions of the sound-speed...
3	Analysis of time series of solar-like oscillations - Applications to the Sun and HD52265 / Zeitreihenanalyse sonnenähnlicher Oszillationen Anwendung auf Beobachtungen der Sonne und HD52265 Stahn, Thorsten 05 October 2010 (has links) No description available. 520 Astronomie Physics Asteroseismologie Helioseismologie sonnenähnliche Schwingungen Rotation Zeitreihenanalyse sonnenähnliche Sterne einzelne Sterne: HD52265 Sonne CoRoT SoHO/VIRGO Asteroseismology helioseismology solar-like oscillations rotation time series analysis solar-type stars individual stars: HD52265 Sun CoRoT SoHO/VIRGO 39.22 THO 000: Asteroseismologie Oszillation {Sterne} THE 400: Rotation Eigenbewegung {Astronomie: Sterne} TGC 600: Helioseismologie Sonnenschwingungen {Astronomie}

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