Solar Physics

, Volume 175, Issue 2, pp 613–644

First Results from the Soho Ultraviolet Coronagraph Spectrometer

  • J. L. Kohl
  • G. Noci
  • E. Antonucci
  • G. Tondello
  • M. C. E. Huber
  • L. D. Gardner
  • P. Nicolosi
  • L. Strachan
  • S. Fineschi
  • J. C. Raymond
  • M. Romoli
  • D. Spadaro
  • A. Panasyuk
  • O. H. W. Siegmund
  • C. Benna
  • A. Ciaravella
  • S. R. Cranmer
  • S. Giordano
  • M. Karovska
  • R. Martin
  • J. Michels
  • A. Modigliani
  • G. Naletto
  • C. Pernechele
  • G. Poletto
  • P. L. Smith
Article

DOI: 10.1023/A:1004903206467

Cite this article as:
Kohl, J.L., Noci, G., Antonucci, E. et al. Sol Phys (1997) 175: 613. doi:10.1023/A:1004903206467

Abstract

The SOHO Ultraviolet Coronagraph Spectrometer (UVCS/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 HI Lα and Lβ, Ovi 1032 Å and 1037 Å, Mgx 625 Å, Fexii 1242 Å and several others. Intensities for Mgx 610 Å, Sixii 499 Å, and 520 Å, Sx 1196 Å, 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 about 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 anisotropic velocity distributions with the smaller values in the radial direction.

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • J. L. Kohl
    • 1
  • G. Noci
    • 2
  • E. Antonucci
    • 3
  • G. Tondello
    • 4
  • M. C. E. Huber
    • 5
  • L. D. Gardner
    • 1
  • P. Nicolosi
    • 4
  • L. Strachan
    • 1
  • S. Fineschi
    • 1
  • J. C. Raymond
    • 1
  • M. Romoli
    • 2
  • D. Spadaro
    • 6
  • A. Panasyuk
    • 1
  • O. H. W. Siegmund
    • 7
  • C. Benna
    • 9
  • A. Ciaravella
    • 5
  • S. R. Cranmer
    • 1
  • S. Giordano
    • 9
  • M. Karovska
    • 1
  • R. Martin
    • 10
  • J. Michels
    • 1
  • A. Modigliani
    • 2
  • G. Naletto
    • 4
  • C. Pernechele
    • 4
  • G. Poletto
    • 8
  • P. L. Smith
    • 1
  1. 1.Harvard-Smithsonian Center for AstrophysicsCambridgeU.S.A.
  2. 2.Università di FirenzeFirenzeItaly
  3. 3.Osservatorio Astronomico di TorinoPino TorineseItaly
  4. 4.Università di PadovaPadovaItaly
  5. 5.Space Science Dept., ESA/ESTECNoordwijkThe Netherlands
  6. 6.Osservatorio Astrofisico di CataniaCataniaItaly
  7. 7.Space Sciences LaboratoryUniversity of CaliforniaBerkeleyU.S.A.
  8. 8.Osservatorio Astrofisico di ArcetriFirenzeItaly
  9. 9.Università di TorinoTorinoItaly
  10. 10.Institut d'Astrophysique SpatialeOrsayFrance