Fast downflows in a chromospheric filament. Issue Volume 15:Issue S354(2019) (June 2019)

• Record Type: Journal Article
• Authors: Sowmya, K.; Lagg, A.; Solanki, S. K.; Castellanos Durán, J. S.
• Editors: Kosovichev, Alexander; Strassmeier, Klaus; Jardine, Moira
• Is Part Of: Proceedings of the International Astronomical Union. Volume 15:Issue S354(2019)
• Page Start: 454
• Page End: 457
• Publication Date: 2019-06
• Subjects: Sun: filaments, -- Sun: chromosphere, -- Sun: magnetic fields; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S174392131900992X
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: An active region filament in the upper chromosphere is studied using spectropolarimetric data in He i 10830 Å from the GREGOR telescope. A Milne-Eddingon based inversion of the Unno-Rachkovsky equations is used to retrieve the velocity and the magnetic field vector of the region. The plasma velocity reaches supersonic values closer to the feet of the filament barbs and coexist with a slow velocity component. Such supersonic velocities result from the acceleration of the plasma as it drains from the filament spine through the barbs. The line-of-sight magnetic fields have strengths below 200 G in the filament spine and in the filament barbs where fast downflows are located, their strengths range between 100 - 700 G.