Spectroscopic far ultraviolet observations of transition zone instabilities and their possible role in a pre-flare energy build-up
| Autor: | V. E. Scherrer, Guenter E. Brueckner, N. P. Patterson |
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| Rok vydání: | 1976 |
| Předmět: |
Physics
Solar flare Astrophysics::High Energy Astrophysical Phenomena Astronomy Astronomy and Astrophysics Astrophysics Solar physics law.invention Loop (topology) Space and Planetary Science Atomic electron transition law Ionization Transition zone Astrophysics::Solar and Stellar Astrophysics Line (formation) Flare |
| Zdroj: | Solar Physics. 47:127-146 |
| ISSN: | 1573-093X 0038-0938 |
| DOI: | 10.1007/bf00152250 |
| Popis: | (1) Highly flare-productive new emerging active regions are characterized by numerous small low-lying loops which frequently show a chaotic pattern. (2) Flare activity in such a region subsides as the chaotic loop structures relax and expand into a bipolar configuration. (3) The transition zone in such an active region is highly unstable as shown by broadened and shifted non-thermal line profiles of medium ionized elements like Si iii, Si iv, C iv, etc. (4) These transition zone instabilities which occur as isolated events in active regions of low flare productivity are often observed prior to flares. (5) Transition zone instabilities can be traced to the footpoints of active loops, and seem to be accompanied by heating of the loop. (6) The loops vary in size and show differing degrees of activity, with the brightest and most compact ones seemingly being in a pre-flare state which results in the catastrophic energy release along the loop during a flare. |
| Databáze: | OpenAIRE |
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