A Method for Characterizing Rotation Rates in the Soft X-Ray Corona
Differential rotation rates of soft X-ray features in the solar corona are quantified by a method of harmonic filtering using the Lomb-Scargle periodogram. This approach leads reasonably to a quantitative discrimination between uncertainty estimates and spectral leakage of the fundamental rotation f...
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Published in | Solar physics Vol. 189; no. 2; pp. 271 - 288 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Dordrecht
Springer Nature B.V
01.11.1999
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Subjects | |
Online Access | Get full text |
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Summary: | Differential rotation rates of soft X-ray features in the solar corona are quantified by a method of harmonic filtering using the Lomb-Scargle periodogram. This approach leads reasonably to a quantitative discrimination between uncertainty estimates and spectral leakage of the fundamental rotation frequency due to the presence of multiple rotating tracers. Mean rotation rates as a function of latitude and year are calculated for the years 1992-1997 (roughly the declining phase of the last solar activity cycle). The corona is found to have a small but measurable latitudinal gradient in rotation rate. The presence of multiple features places a lower bound of 1-2% on the relative uncertainties with which a `mean' rotation rate can be measured. The results are compared with autocorrelation estimates and found to agree within 1σ.[PUBLICATION ABSTRACT] |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0038-0938 1573-093X |
DOI: | 10.1023/A:1005243924098 |