Abstract
We present results derived from the analysis of an equatorial streamer structure as observed by the UVCS instrument aboard SOHO. From observations of the H I Lyα and Lyβ lines we infer the density and temperature of the plasma. We develop a preliminary axisymmetric, magnetostatic model of the corona which includes the effects of gas pressure gradients on the magnetic structure. We infer a coronal plasma β > 1 in the closed field regions and near the cusp of the streamer. We add to the model a parallel velocity field assuming mass flux conservation along magnetic flux tubes. We then compute the Lyα emissivity and the line-of-sight integrals to obtain images of Lyα intensity, taking into account projection effects and Doppler dimming. The images we obtain from this preliminary model are in good general agreement with the UVCS observations, both qualitatively and quantitatively.
Similar content being viewed by others
References
Cranmer, S. R., et al.: 1999, Astrophys. J., 511, 481.
Kohl, J. L., et al.: 1995, Solar Phys., 162, 313.
Li, J., Raymond, J. C., and Acton, L. W.: 1998, Solar Phys., submitted.
Noci, G., et al.: 1993, Solar Phys., 147, 73.
Raymond, J. C., et al.: 1997, Solar Phys., 175, 645.
Wang, A. H., et al.: 1998, J. Geophys. Res., 103, 1913.
Withbroe, G. L., Kohl, J. L., and Weiser, H.: 1982, Space Science Rev., 33, 17.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Vásquez, A.M., Raymond, J.C. & Van Ballegooijen, A.A. UVCS Observations and Modeling of Streamers. Space Science Reviews 87, 335–338 (1999). https://doi.org/10.1023/A:1005106131009
Issue Date:
DOI: https://doi.org/10.1023/A:1005106131009