Title: Statistical spectroscopic analysis of a quiescent prominence
observed in hydrogen Lyman lines by SoHO/SUMER and MgII h&k lines by
IRIS

Authors: P. Schwartz 1, S. Gunár 2, J. Koza 1, P. Heinzel 2

 1 Astronomical Institute of Slovak Academy of Sciences, Tatranská
Lomnica, Slovakia

 2 Astronomical Institute, Czech Academy of Sciences, Ondřejov, Czech
Republic

Abstract:
A quiescent prominence was observed on October 22, 2013 at NW limb
quasi- simultaneously and nearly co-spatially by the space
spectrographs: in the Lyman line series of hydrogen by SoHO/SUMER and in
the MgII h&k UV lines by IRIS. Only a dense and compact structure of the
prominence was analyzed, because this part is quiet and therefore
suitable for quasi-static non-LTE modeling. This part of the prominence
is also well visible in H_alpha filtergram images. Spectroscopic
analysis of the hydrogen Lyman and MgII h&k line profiles is done
firstly by studying of statistical occurrence of profiles of different
types – one-, two-, three-, four-and-more-peak profiles and peculiar
profiles (which cannot be assigned to any of the previous four types)
– within the analysed part of the prominence. Then, statistical
analysis of characteristics of observed profiles was done. Profile
characteristics commonly used in our non-LTE modelling of the prominence
fine structure – integral intensities, depth of the central reversal
and asymmetry of the peaks – are defined only for profiles with one
peak (purely emissive) or double-peaked. Thus, only one- and two-peak
profiles were included into analysis by the three profile
characteristics and their statistical distributions are represented by
histograms. Results of the statistical analysis of observed data are to
be soon compared with the analogous analysis made with synthetic
profiles obtained using the 2D non-LTE models of the fine structure of
prominence. The non-LTE models are already prepared; for hydrogen the
model was already used for modelling of several different quiescent
prominences, computer code of the MgII 2D model was finished recently.
It was just necessary to develop the sophisticated method for
construction of the incident radiation for arbitrary date (date of the
prominence observations) used as a boundary condition of the
radiative-transfer calculations for both hydrogen and MgII lines taking
into account variations with solar cycle; this was completely done now
as you learnt from the previous talk of Julius Koza.