First Results from the SOHO Ultraviolet Coronagraph Spectrometer
In: The First Results from SOHO ISBN: 9789401062046; (1997)
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Zugriff:
The SOHO Ultraviolet Coronagraph Spectrometer (UYCS/SOHO) is being used to observe the extended solar corona from 1.25 to 10 R from Sun center. Initial observations of polar coronal holes and equatorial streamers are described. The observations include measurements of spectral line profiles for H I Lα and Lβ, O VI 1032 A and 1037 A, Mg × 625 A, Fe XII 1242 A and several others. Intensities for Mg × 610 A, Si XII 499 A, and 520 A, S × 1196 A, and 22 others have been observed. Preliminary results for derived H0, O5+, Mg9+, and Fe11+ velocity distributions and initial indications of outflow velocities for O5+ are described. In streamers, the H0 velocity distribution along the line of sight (specified by the value at e-1, along the line of sight) decreases from a maximum value of about 180 km s-1 at 2 R to about 140 km s-1 at 8 R. The value for O5+ increases with height reaching a value of 150 km s-1 at 4.7 R. In polar coronal holes, the O5+ velocity at e-1 is atout equal to that of H0 at 1.7 R and significantly larger at 2.1 R. The O5+ in both streamers and coronal holes were found to have amsotropic velocity distributions with the smaller values in the radial direction.
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First Results from the SOHO Ultraviolet Coronagraph Spectrometer
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Autor/in / Beteiligte Person: | Ciaravella, Angela ; Panasyuk, Alexander ; Michels, J. ; Raymond, John C. ; Noci, Giancarlo ; Poletto, Giannina ; Pernechele, Claudio ; Huber, M. C. E. ; Strachan, Leonard ; Tondello, Giuseppe ; Naletto, Giampiero ; Gardner, L. D. ; Siegmund, O. H. W. ; Antonucci, Ester ; Giordano, S. ; Benna, Carlo ; Cranmer, Steven R. ; Spadaro, Daniele ; Nicolosi, Piergiorgio ; Fineschi, Silvano ; Romoli, Marco ; Martin, Randall V. ; Karovska, Margarita ; Smith, P. L. ; Modigliani, A. ; Kohl, J. L. |
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Quelle: | The First Results from SOHO ISBN: 9789401062046; (1997) |
Veröffentlichung: | Springer Netherlands, 1997 |
Medientyp: | unknown |
ISBN: | 978-94-010-6204-6 (print) |
DOI: | 10.1007/978-94-011-5236-5_34 |
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