Flare Expansion to a Magnetic Rope Accompanied by Rare Radio Bursts. (arXiv:2101.08633v1 [astro-ph.SR])

Flare Expansion to a Magnetic Rope Accompanied by Rare Radio Bursts. (arXiv:2101.08633v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Zemanova_A/0/1/0/all/0/1">Alena Zemanov&#xe1;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Karlicky_M/0/1/0/all/0/1">Marian Karlick&#xfd;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kasparova_J/0/1/0/all/0/1">Jana Ka&#x161;parov&#xe1;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dudik_J/0/1/0/all/0/1">Jaroslav Dud&#xed;k</a>

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.

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.

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