Abstract
Additional observations of He ii (304 Å) and Si xi (303 Å) were obtained from a high resolution rocket spectrograph flown on 30 August, 1973 and 20 January, 1975. The profile of the He ii (304 Å) line is everywhere clearly non-gaussian across the solar disk, except in bright active areas. Near the limb, the profile is distinctly reversed. The profile of the Si xi (303 Å) line is essentially gaussian for all regions across the solar disk. Measurements of the He ii/Si xi intensity ratio indicate that the average value of this ratio across the disk depends markedly on solar activity, being about 10∶1 for a moderate level of activity and 30∶1 for a quiet Sun.
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References
Cushman, G. W. and Rense, W. A.: Astrophys. J. 207, L61.
Cushman, G. W., Farewell, L., Godden, G., and Rense, W. A.: 1975, J. Geophys. Res. 80, 482.
Jacobs, V. L., Davis, J., Kepple, P. C., and Blaha, M.: 1977, Astrophys. J. 215, 690.
Jordan, C.: 1969, Monthly Notices Roy. Astron. Soc. 142, 501.
Levine, R. H., Altschuler, M. D., Harvey, J. W., and Jackson, B. V.: 1977, Astrophys. J. 215, 636.
Nolte, J. T., Kreiger, A. S., Timothy, A. F., Vaiana, G. S., and Zombeck, M. V.: 1976, Solar Phys. 46, 291.
Pneuman, G. W. and Kopp, R. A.: 1978, Solar Phys. 57, 49.
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Cushman, G.W., Rense, W.A. Solar Heii(304 Å) and Si xi(303 Å) line profiles. Sol Phys 58, 299–305 (1978). https://doi.org/10.1007/BF00157275
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DOI: https://doi.org/10.1007/BF00157275