PREDNASAJUCI / LECTURER :

Pavol Schwartz

Astronomical Institute, Slovak Academy of Sciences,
059 60 Tatranská Lomnica

NAZOV / TITLE :

Modelling of solar filaments and prominences using their
observations in hydrogen spectral lines and non-LTE
radiative transfer in 1D and 2D geometry

ABSTRAKT / ABSTRACT :

I present a review of modelling of solar prominences and
filaments observed spectroscopically in the Lyman line
series of hydrogen and in H_alpha using detailed non-LTE
radiative transfer (RTE) from the year 2006 up to date.
The so-called `forward modelling’ was used, it means that
extended catalogues of synthetic profiles were calculated
and the best model was searched by chi-square minimization
between synthetic and observed spectral line profiles.
The modelling was made for diagnostics of hydrogen plasma
of both quiescent and active prominences/filaments to
understand better their nature and also physical processes
leading to their possible activation. Prominence/filament
was approximated by a geometrically simple slab.
A possibility of increase of temperature towards the slab
edges – so called prominence-corona transition regions
(PCTRs) –  were also introduced into the modelling, because
their occurrence in peripheral parts of filaments/prominences
is evident from observations. We started with the modelling
in 1D geometry, but in the year 2010 we realized a necessity
of 2D geometry, because profiles from peripheral parts of
filaments/prominences could not be fitted reliably when the
slab in the 1D geometry is irradiated from the solar surface
only at its bottom. On the other hand, 2D slab is irradiated
both from its bottom and sides. Later, magnetohydrostatic
equilibrium and fine structure (multi-slabs) was applied in
the modelling of solar prominences. Now, we are addopting
the 2D-slab codes also for modelling of eruptive prominences
and we are calculating grids of models containing synthetic
Lyman-alpha intensities which will be later compared with
observations in the Lyman_alpha channel made by the METIS
coronograph on board of the Solar Orbiter satellite.