Plasma velocity field of two quiescent prominences with different morphology
Abstract
We processed by means of the automated microdensitometer MDM6 Joyce Loebl of the Institute of Astronomy of BAS series of H-alpha prominence spectrograms taken with the Large Coronagraph of the Astronomical Institute of Wroclaw University. The spectrograms were taken from two quiescent prominence at various locations of the spectrograph slit against the prominences bodies. The spectra represent a small part (of about 15 AA) of the prominences spectra centered at H-alpha. The corresponding range of the spectrum of the terrestrial atmosphere is supperimposed on the spectrograms. Some of the atmospheric lines have been used for determination of the wavelenght-pixel ratio and a point of eparture, necessary in the procedure of computation of the H-alpha emission location, H-alpha line profiles and the line-of-light velocity components of the prominence plasma in the observed spectral range. In the sequences of the H-alpha slit jaw filtegrams, taken simultaneosly with the spectra, the slit position against the prominence body is clearly seen. We got a good correspondence between the prominence structural elements identified in the H-alpha filtegrams and the corresponding spectral cuts. This permits us to construct isomaps of the prominences line-of-sight velocity component. The obtained isomaps are used for the analysis of the prominence plasma kinematics. Some peculiarities in the velocity picture near the prominences surface is explained as a result of the momentum transmission by the surface wave modes of the supporting large scal local magnetic field.
- Publication:
-
Joint European and National Astronomical Meeting
- Pub Date:
- 1997
- Bibcode:
- 1997jena.confE..52P