Properties and evolution of Active Region outflows in the intermediate corona
- Submitted by: Luca Zangrilli, INAF - Osservatorio Astrofisico di Arcetri
- Authors: L. Zangrilli and G. Poletto
- Session: Monday morning posters.
Our purpose is to study the evolution of Active Region outflows from the time an AR first forms, through the time it dies, after several transits at the solar limb. We analyze data acquired by SOHO/UVCS, at altitudes ranging from 1.5 to 2.3 solar radii, at mid latitudes. Outflow speeds and electron densities of fluxes from the Active Region have been inferred by means of the Doppler dimming technique applied to UVCS spectra, that include the H I Ly alpha line and the O VI doublet lines at 1031.9 and 1037.6Å, over several rotations of the Sun. We also studied changes in the silicon abundance, where AR outflows are found, by analysing the intensity of the second order line Si 520Å in O VI channel spectra. Our results support ARs as sources of slow wind.