The influence of coronal radiation on solar prominence plasma

QB Astronomy;QC Physics

Brown, Gerrard Martyn ; Labrosse, Nicolas

University:University of Glasgow

Department:School of Physics and Astronomy

关键词: Sun, solar, prominence, corona, radiation, radiative transfer;   

Others  :  http://theses.gla.ac.uk/7067/7/2015BrownPhD.pdf

来源: University of Glasgow

【 摘 要 】

Solar prominences are structures located within the solar corona. The flow ofenergy within them is through radiative processes and this needs to be studied usingradiative transfer, which is dependent upon the radiation entering the prominence. Fora full understanding of the radiative processes within the prominence we need to fullyaccount for all the radiation that originates outwith the prominence but still influencesit. Previous studies have only looked at the radiation from the disc, this thesis willadd to this the radiation from the corona and investigate the effects of this. Chapter1 introduces the Sun and prominences, to explain the conditions prominences occurin. In chapter 2 radiative transfer is discussed, it is shown where the 1-D form ofthe radiative transfer equation and the statistical equilibrium equation comes from.Previous studies of prominences using radiative transfer are discussed, and we explainthe radiative transfer code which will be modified to include the coronal radiation. Toadd the radiation from the corona it is necessary to know what the coronal radiationwould be visible to the prominence as spectra observed from outside the corona wouldnot be suitable for the light an object within the corona receives and so in chapter 3the radiation that a prominence within the corona would receive is calculated. Themethods for determining the radiation from the corona which would be visible to theprominence are explained. The results for this at various heights are shown, andthis shows that there would be sufficient difference between the radiation receviedby prominencies at different heights to justify recalculating the coronal radiation fordifferent heights. The coronal radiation is added to the incident radiation below 912 ̊Ain chapter 4. The radiative transfer code is modified so that it can receive the lightfrom either individual lines or from many lines averaged over a wavelength range. Itis demonstrated that different lines will have different degrees of influence over theionisation of the prominence by moving an individual test line and so when we addiiradiation from lines average over wavelength ranges we take this into account. It isshown that the effects of coronal radiation on the hydrogen in the prominence for iso-thermal iso-baric slabs, and for slabs with a PCTR (Prominence to Corona TransitionRegion). The coronal radiation is then added to the helium continua in chapter 5.The effects of the coronal radiation on the helium in the prominence for iso-thermaliso-baric slabs and for slabs with a PCTR are shown. The coronal radiation has asignificant effect on the condition and emissions of a prominence, and must be takeninto account to fully understand the radiative processes of a prominence.