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| Titel |
Relationship between extreme ultraviolet microflares and small-scale magnetic fields in the quiet Sun |
| VerfasserIn |
Fayu Jiang, Jun Zhang, Shuhong Yang |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250124311
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| Publikation (Nr.) |
 EGU/EGU2016-3729.pdf |
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| Zusammenfassung |
| Microflares are small dynamic signatures observed in X-ray and extreme-ultraviolet channels.
Because of their impulsive emission enhancements and wide distribution, they are thought to
be closely related to coronal heating. By using the high resolution 171 Å images from the
Atmospheric Imaging Assembly and the lines-of-sight magnetograms obtained by the
Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we trace
10794 microflares in a quiet region near the disk center with a field of view of 960′′× 1068′′
during 24 hr. The microflares have an occurrence rate of 4.4 × 103 hr−1 extrapolated over
the whole Sun. Their average brightness, size, and lifetime are 1.7 I0 (of the quiet Sun), 9.6
Mm2, and 3.6 min, respectively. There exists a mutual positive correlation between the
microflares’ brightness, area and lifetime. In general, the microflares distribute
uniformly across the solar disk, but form network patterns locally, which are similar to
and matched with the magnetic network structures. Typical cases show that the
microflares prefer to occur in magnetic cancellation regions of network boundaries. We
roughly calculate the upper limit of energy flux supplied by the microflares and
find that the result is still a factor of ∼15 below the coronal heating requirement. |
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