| Presenter: | Clementina Sasso |
| Affiliation: | Max Planck Institute for Solar System Research |
| Title: | The He~{\sc{i}} 10830~{\AA} multiplet: analysis of the Stokes vector in a flaring region |
| Authors: | C. Sasso, A. Lagg, S. K. Solanki, R. Aznar Cuadrado, L. Teriaca, M. Collados |
| Form: | poster |
| Abstract: | We analyze observations of a flaring active region made in the chromospheric He~{\sc{i}} 10830~{\AA} multiplet. Full Stokes vector data were recorded with the new Tenerife Infrared Polarimeter (TIP-II) at the German Vacuum Tower Telescope (VTT). While scanning the region, a flare of class C2.0 erupted in the west part of the active region NOAA 10763. A filament and the flare ribbons were visible in the H$\alpha$ slit jaw camera images. The analysis of the He Stokes profiles reveals huge differences in the profile shapes. The majority of the profiles show multiple atmospheric components in the chromospheric He lines which are strongly blue- and/or redshifted, resulting in unusually broad Stokes I absorptions and complex Stokes $V$ signatures. We obtained maps of the line-of-sight velocities and the magnetic field vector in the chromosphere by applying a Milne-Eddington based inversion code to the He~{\sc{i}} lines. Results show supersonic downflows and upflows associated with the different components, but only a single magnetic field component associated with any given pixel. We also investigate the connection between the flare at coronal heights and what we observe at chromospheric levels by comparing TRACE 171~{\AA} data with the He 10830 observation. |
| Session: | 2. Polarization physics in magnetized media |
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