FILAMENT OBSERVATIONS WITH SOHO SUMER CDS - THE BEHAVIOR OF HYDROGEN LYMAN LINES/

On 21 September 1996, a filament close to an area of enhanced network was observed with the Solar Ultraviolet Measurements of Emitted Radiat ion (SUMER) spectrometer and Coronal Diagnostic Spectrometer (CDS). CD S provided intensity, Doppler shift and linewidth maps of the region i n six lines whose temperature range covers 10(4) to 10(6) It. SUMER ob servations consisted of maps of the region in four hydrogen Lyman line s (L delta, L epsilon, L-6, L-7) and a S VI line (944 Angstrom). In al l the Lyman lines we detect a central absorption and an asymmetry in t he intensity of the two peaks. First NLTE computations indicate that s uch reversed Lyman profiles and their absolute intensities can be repr oduced with the existing filament models provided that we take into ac count a prominence-corona transition region (PCTR). We discuss the Lym an lines' asymmetry in terms of macroscopic flows by comparison with t he He I line Doppler shifts observed with CDS.