Hot Erupting Prominence in the Core of a CME: Analysis of SOHO/UVCS L-alpha and SOHO/LASCO Visible-Light Observations
Sonja Jejcic (Faculty of Mathematics and Physics, University of Ljubljana, Slovenia)
Abstract. In our study we concentrate on determination of the physical parameters of erupting prominences embedded in the core of Coronal Mass Ejections (CMEs), using the hydrogen Lyman α line (Lα) and visible light (VL) detected at large altitudes, typically larger than 0.6 solar radii above the limb. Contrary to the solar corona, in cool structures like prominences the Lα line is strong and can be optically thick. The proper analysis requires rather complex non-LTE radiative-transfer modelling. We explore SOHO/UVCS and SOHO/LASCO C2 data of one particular CME event of August 2, 2000. Our statistics of a large number of pixels shows that about one half of them exhibits high temperatures around 100000 K, while the other one shows much lower temperatures. Hot plasma is strongly ionized and its emission is thus weaker and mostly optically thin. We also show how the plasma filling factor affects the plasma diagnostics using UVCS and LASCO data. Because METIS onboard the Solar Orbiter will cotemporary observe the coronal structures in VL and in UV (Lα), it will be possible to derive, with a technique similar to what is shown here, important information on the erupting prominence plasmas embedded in the core of CMEs and crossing the instrument field of view.
Contributed Talk
