Study of an Extended EUV Filament Using SoHO/SUMER Observations of the Hydrogen Lyman Lines. II. Lyman α Line Observed During a Multi-wavelength Campaign

0386865 - ASÚ 2013 RIV NL eng J - Journal Article
Schwartz, Pavol - Schmieder, B. - Heinzel, Petr - Kotrč, Pavel
Study of an Extended EUV Filament Using SoHO/SUMER Observations of the Hydrogen Lyman Lines. II. Lyman α Line Observed During a Multi-wavelength Campaign.
Solar Physics. Roč. 281, č. 2 (2012), s. 707-728. ISSN 0038-0938. E-ISSN 1573-093X
R&D Projects: GA ČR GAP209/10/1680; GA ČR GAP209/10/1706
Grant - others:SAV(SK) VEGA 2/0108/12
Institutional research plan: CEZ:AV0Z10030501
Keywords : prominences * models * quiescent
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 3.256, year: 2012

We found that the width of the filament depends on the wavelength in which the filament is observed (around 15 arcsec in Hα, 30 arcsec in Lα, and 60 arcsec in EUV). In Lα the filament is wider than in Hα because cool plasma, not visible in Hα, is optically thick at the Lα line center, and its presence blocks the coronal emission. We have derived physical plasma properties of this filament fitting the Lyman spectra and Hα profiles by using a 1D isobaric NLTE model. We have estimated the geometrical filling factor in the filament channel. Its low value indicates the presence of multi-threads.
Permanent Link: http://hdl.handle.net/11104/0217795