Astronomy and Astrophysics – Astrophysics
Scientific paper
Dec 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997aas...19112004z&link_type=abstract
American Astronomical Society, 191st AAS Meeting, #120.04; Bulletin of the American Astronomical Society, Vol. 29, p.1402
Astronomy and Astrophysics
Astrophysics
1
Scientific paper
Although it is generally accepted that quiescent filaments have strong horizontal axial magnetic field (Leroy,1984) the field configuration in the legs (``barbs'' or ``feet'') is controversial. Previous observations indicate both rising and falling Doppler motions in such appendages, at speeds less than ``free-fall'' (Dunn,1960; Yi et al,1991; Zirker et al, 1994). Such observations could be consistent with the presence of horizontal magnetic fields that are slowly drifting up and down carrying plasma with them. However the H alpha fine-structure strongly suggests the presence of vertical or highly inclined magnetic field lines. Without vector field observations it is difficult to choose between these alternatives. In an attempt to clarify the issue, H alpha observations of a quiescent filament were made during its passage across the disk, from 12 to 20 April, 1993 at the Big Bear Observatory. Remarkable high-speed flows (of order 20 km/s ) were seen along the axial "spine" of the filament. Substantially slower motions were detected in the barbs. The paradox of non-free-fall motions in the predominantly vertically directed threads of barbs, will be discussed briefly. Bommier,V., Landi Degli'Innocenti,E., Leroy, J-L., and Sahal-Brechot, S.: 1994, Solar Phys. 154,231 Dunn, R.B.,1960, Ph D Thesis, Harvard University Engvold,O.: 1976,Solar Phys.49,283. Leroy,J-L. Bommier,V. nd Sahal Brechot,S.:1984, Astronomy and Astrophysics, 131,33. Yi,Z.,Engvold,O. and Keil,S.L.: 1991, Solar Phys. 132,63. Zirker,J.B.,Engvold,O.and Yi,Z. 1994, Solar Phys. 150,81.
Engvold Odbjørn
Martin Sara F.
Zirker Jack B.
No associations
LandOfFree
Plasma Streaming as Indicator of Field Topology in a Quiescent Filament does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Plasma Streaming as Indicator of Field Topology in a Quiescent Filament, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plasma Streaming as Indicator of Field Topology in a Quiescent Filament will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1178541