Magnetic support and dynamics of a prominence observed by THEMIS and IRIS
|Auteur(s) supplémentaire(s)||Tian H. 2, Lopez-Ariste A.3, Kucera T.4, Dalmasse K. 5, Mein P.1, Golub L.2|
|Institution(s) supplémentaire(s)||2. SAO, Cambridge, MS, USA, 3. IRAP, Toulouse 4. NASA,GSFC,MD, USA, 5. NCAR Boulder USA|
In September 2013 several prominences were observed with the IRIS spectrograph during a 60 day-long international program. We will present one set of observations obtained using multiple instruments on September 24.SDO/AIA and IRIS slit-jaws provided images of the prominence corresponding to different physical conditions of the transition region between the cool plasma and the corona.
The vector magnetic field was derived from THEMIS (Tenerife) observations using the He D3 depolarisation due to the magnetic field. The inversion code (PCA ) takes into account the Hanle and the Zeeman effects. Movies from SDO/AIA in 304 A and Hinode/SOT in Ca II show the dynamics of the fine structures in the plane of the sky. From Mg II and Si IV lines observed by IRIS and H-alpha observed by the Multi-channel subtractive spectrograph (MSDP) in the Meudon solar tower we derived the Dopplershifts of the fine structures. The profiles of the Mg II lines are narrow
(FHWM=0.15 A) and not reversed, contrary to the predictions of the theoretical models (Paletou et al 1993). We could resolve the velocity of several structures along the LOS with Dopplershifts as high as 60 km/s.