Plasma physical parameters of a prominence embedded in the core of a Coronal Mass Ejection
Abstract
We determine the plasma physical parameters of an erupting prominence embedded in the core of a CME, combininging visible light coronagraphic images from SOHO/LASCO with UV spectra acquired by SOHO/UVCS. Strong UV emissions were detected in the hydrogen Lyman-α and Lyman-β lines and C III line. Visible light and UV intensities have been used to estimate the projected thickness and velocity of the prominence, together with the effective plasma temperature, microturbolent velocity, and column density. These parameters have been used to constrain 1D NLTE modeling of the erupting plasma, taking into account the effects of large flow velocities (Doppler dimming). Roughly one-half of considered points in the prominence body show a non-negligible Lyman-α optical thickness. Comparison between the calculated and the measured intensities of the two Lyman lines was also used to derive the geometrical filling factor. Results show that the erupting prominence plasma is relatively hot, with a low electron density, a wide range of effective thicknesses, a rather narrow range of radial flow velocities, and a microturbulence of about 25 km/s. This analysis provides a basis for future diagnostics of prominences using the METIS coronagraph on board the Solar Orbiter mission.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E.267B