2020/12/01 by Alena Zemanová, Marian Karlický, Jana Kašparová +1
Physics and Astronomy · #Flare #Ionosphere and magnetosphere dynamics #Magnetic field #Magnetic reconnection #Pulsars and Gravitational Waves Research #Rope #Solar and Space Plasma Dynamics #Solar flare #Transverse plane #Ultraviolet #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/abc424
published as 2020ApJ...905..111Z · 24 pages, 11 figures
openalex publication_date 2020/12/01 · openalex created_date 2021/01/05 · arxiv created 2021/01/21 · arxiv updated 2021/01/22 · openalex updated_date 2026/08/06
Abstract We present multispectral analysis (radio, H α , ultraviolet (UV)/extreme ultraviolet (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 a 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.