The influence of coronal radiation on solar prominence plasma

Brown, Gerrard Martyn (2015) The influence of coronal radiation on solar prominence plasma. PhD thesis, University of Glasgow.

Abstract

Solar prominences are structures located within the solar corona. The flow of
energy within them is through radiative processes and this needs to be studied using
radiative transfer, which is dependent upon the radiation entering the prominence. For
a full understanding of the radiative processes within the prominence we need to fully
account for all the radiation that originates outwith the prominence but still influences
it. Previous studies have only looked at the radiation from the disc, this thesis will
add to this the radiation from the corona and investigate the effects of this. Chapter
1 introduces the Sun and prominences, to explain the conditions prominences occur
in. In chapter 2 radiative transfer is discussed, it is shown where the 1-D form of
the radiative transfer equation and the statistical equilibrium equation comes from.
Previous studies of prominences using radiative transfer are discussed, and we explain
the radiative transfer code which will be modified to include the coronal radiation. To
add the radiation from the corona it is necessary to know what the coronal radiation
would be visible to the prominence as spectra observed from outside the corona would
not be suitable for the light an object within the corona receives and so in chapter 3
the radiation that a prominence within the corona would receive is calculated. The
methods for determining the radiation from the corona which would be visible to the
prominence are explained. The results for this at various heights are shown, and
this shows that there would be sufficient difference between the radiation recevied
by prominencies at different heights to justify recalculating the coronal radiation for
different heights. The coronal radiation is added to the incident radiation below 912 ̊A
in chapter 4. The radiative transfer code is modified so that it can receive the light
from either individual lines or from many lines averaged over a wavelength range. It
is demonstrated that different lines will have different degrees of influence over the
ionisation of the prominence by moving an individual test line and so when we addii
radiation from lines average over wavelength ranges we take this into account. It is
shown 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 Transition
Region). 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-thermal
iso-baric slabs and for slabs with a PCTR are shown. The coronal radiation has a
significant effect on the condition and emissions of a prominence, and must be taken
into account to fully understand the radiative processes of a prominence.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Sun, solar, prominence, corona, radiation, radiative transfer
• Subjects: Q Science > QB Astronomy; Q Science > QC Physics
• Colleges/Schools: College of Science and Engineering > School of Physics and Astronomy
• Supervisor's Name: Labrosse, Dr. Nicolas
• Date of Award: 2015
• Depositing User: Gerrard Brown
• Unique ID: glathesis:2015-7067
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 05 Feb 2016 16:23
• Last Modified: 26 Jul 2016 07:45
• URI: https://theses.gla.ac.uk/id/eprint/7067