Coronal Hole Properties Observed with Sumer
We analyze SUMER spectra of 14 lines belonging to 12 ions, obtained on both sides of the boundary of polar coronal holes as well as at other locations along the limb. We compare line intensities, shifts and widths in coronal holes with values obtained in the quiet Sun. We find that with increasing f...
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Published in | Space science reviews Vol. 87; no. 1-2; pp. 315 - 318 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Dordrecht
Springer Nature B.V
01.01.1999
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Online Access | Get full text |
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Summary: | We analyze SUMER spectra of 14 lines belonging to 12 ions, obtained on both sides of the boundary of polar coronal holes as well as at other locations along the limb. We compare line intensities, shifts and widths in coronal holes with values obtained in the quiet Sun. We find that with increasing formation temperature, spectral lines show an increasingly stronger blueshift in coronal holes relative to the quiet Sun at an equal heliospheric angle. The width of the lines is generally larger (by a few km/s) inside the coronal hole. Intensity measurements show the presence of the coronal hole in Ne VIII lines as well as in Fe XII, with evidence for a slightly enhanced emission in polar coronal holes for lines formed below 10 super(5) K. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 SourceType-Scholarly Journals-2 ObjectType-Feature-2 ObjectType-Conference Paper-1 SourceType-Conference Papers & Proceedings-1 ObjectType-Article-3 ObjectType-Article-1 |
ISSN: | 0038-6308 1572-9672 |
DOI: | 10.1023/A:1005145828283 |