The redshifted footpoints of coronal loops
The physics of coronal loops holds the key to understanding coronal heating and the flow of mass and energy in the region. However, the energy source, structure maintenance and mass balance in coronal loops are not yet fully understood. Observations of blue- and redshifted emissions have repeated...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2008-10-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/26/2955/2008/angeo-26-2955-2008.pdf |
| _version_ | 1811218157381091328 |
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| author | I. E. Dammasch W. Curdt B. N. Dwivedi B. N. Dwivedi S. Parenti |
| author_facet | I. E. Dammasch W. Curdt B. N. Dwivedi B. N. Dwivedi S. Parenti |
| author_sort | I. E. Dammasch |
| collection | DOAJ |
| description | The physics of coronal loops holds the key to understanding coronal heating and
the flow of mass and energy in the region. However, the energy source,
structure maintenance and mass balance in coronal loops are not yet fully understood.
Observations of blue- and redshifted emissions have repeatedly been used in the
construction of loop models. But observations and interpretations of
line shifts have been widely debated. Here we present detailed SUMER observations,
which clearly show a steady downflow in both footpoints of coronal loops
observed at transition region (TR) and lower corona temperatures.
We also show and quantify a correlation existing between this
Doppler shift and the spectral radiance. Our results indicate a strong
correlation which holds from the chromosphere to the lower corona. We suggest that
the downflow in the footpoints may be a common phenomenon on all scales, which could
explain, why on a statistical basis bright pixels tend to be more redshifted.
We conclude by presenting interpretation of such results and their implications in
the light of a viable coronal loop model. The observation of steady downflow
in redshifted footpoints seems to be in conflict with impulsive heating. |
| first_indexed | 2024-04-12T07:05:58Z |
| format | Article |
| id | doaj.art-59aa827709dc489a8a0e59b069038b8a |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-12T07:05:58Z |
| publishDate | 2008-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-59aa827709dc489a8a0e59b069038b8a2022-12-22T03:42:48ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762008-10-01262955295910.5194/angeo-26-2955-2008The redshifted footpoints of coronal loopsI. E. Dammasch0W. Curdt1B. N. Dwivedi2B. N. Dwivedi3S. Parenti4Royal Observatory of Belgium, Brussels, BelgiumMax-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, GermanyMax-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, GermanyDepartment of Applied Physics, Banaras Hindu University, Varanasi, IndiaRoyal Observatory of Belgium, Brussels, BelgiumThe physics of coronal loops holds the key to understanding coronal heating and the flow of mass and energy in the region. However, the energy source, structure maintenance and mass balance in coronal loops are not yet fully understood. Observations of blue- and redshifted emissions have repeatedly been used in the construction of loop models. But observations and interpretations of line shifts have been widely debated. Here we present detailed SUMER observations, which clearly show a steady downflow in both footpoints of coronal loops observed at transition region (TR) and lower corona temperatures. We also show and quantify a correlation existing between this Doppler shift and the spectral radiance. Our results indicate a strong correlation which holds from the chromosphere to the lower corona. We suggest that the downflow in the footpoints may be a common phenomenon on all scales, which could explain, why on a statistical basis bright pixels tend to be more redshifted. We conclude by presenting interpretation of such results and their implications in the light of a viable coronal loop model. The observation of steady downflow in redshifted footpoints seems to be in conflict with impulsive heating.https://www.ann-geophys.net/26/2955/2008/angeo-26-2955-2008.pdf |
| spellingShingle | I. E. Dammasch W. Curdt B. N. Dwivedi B. N. Dwivedi S. Parenti The redshifted footpoints of coronal loops Annales Geophysicae |
| title | The redshifted footpoints of coronal loops |
| title_full | The redshifted footpoints of coronal loops |
| title_fullStr | The redshifted footpoints of coronal loops |
| title_full_unstemmed | The redshifted footpoints of coronal loops |
| title_short | The redshifted footpoints of coronal loops |
| title_sort | redshifted footpoints of coronal loops |
| url | https://www.ann-geophys.net/26/2955/2008/angeo-26-2955-2008.pdf |
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