Flare Expansion to a Magnetic Rope Accompanied by Rare Radio Bursts
| Autor: | Zemanová, Alena, Karlický, Marian, Kašparová, Jana, Dudík, Jaroslav |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | 2020ApJ...905..111Z |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/1538-4357/abc424 |
| Popis: | We present multispectral analysis (radio, H$\alpha$, UV/EUV, and hard X-ray) of a confined flare from 2015 March 12. This flare started within the active region NOAA 12 297 and then it expanded into a large preexisting magnetic rope embedded with a cold filament. The expansion started with several brightenings located along the rope. This process was accompanied by a group of slowly positively drifting bursts in the 0.8--2 GHz range. The frequency drift of these bursts was 45 -- 100 MHz s$^{-1}$. One of the bursts had an S-like form. During the brightening of the rope we observed an unique bright EUV structure transverse to the rope axis. The structure was observed in a broad range of temperatures and it moved along the rope with the velocity of about 240 km s$^{-1}$. When the structure dissipated, we saw a plasma further following twisted threads in the rope. The observed slowly positively drifting bursts were interpreted considering particle beams and we show that one with the S-like form could be explained by the beam propagating through the helical structure of the magnetic rope. The bright structure transverse to the rope axis was interpreted considering line-of-sight effects and the dissipation-spreading process, which we found to be more likely. Comment: 24 pages, 11 figures |
| Databáze: | arXiv |
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