The fine dynamics in homologous and recurrent jets induced by persistent rising loops and mini-filaments

Abstract

Jets are common eruptive phenomena in the solar atmosphere which may occur repeatedly. Many studies of their fine dynamics have been conducted. However, the fine dynamics of persistent interactions among various features that drive recurrent coronal jets have not been studied in detail. In this paper, we use observations from the Solar Orbiter to report persistent interactions between rising loops/mini-filaments and a fan-spine-like structure, which produced more than 22 ejections. Many loops and mini-filaments under the fan-spine-like structure rose with speeds of $8 - 58\,\mathrm{km~s^{-1}}$ and an average of $27\,\mathrm{km~s^{-1}}$. These rising loops and mini-filaments interacted with the fan-spine-like structure successively, producing ejections with speeds ranging from 25 to 186\,\rm km\,s$^{-1}$ and an average at $80\,\rm km~s^{-1}$. We observed the fine dynamics of the drivers of these recurrent jets in detail, including partial eruption of mini-filaments, formation of a new mini-filament by contraction of remaining threads from the partially-erupted mini-filament, and interaction between rising loops (or mini-filaments) and the fan-spine-like structure. Brightenings appeared near the footpoint of these rising structures, followed by the formation of current sheets. Some arcades at the outflow region contracted with speeds of around $10\,\rm km~s^{-1}$, and the outflow region moved at around $8\,\rm km~s^{-1}$ toward the opposite direction. Bright blobs were observed in the current sheets, and they propagated at speeds averaging at $21\,\rm km\,s^{-1}$ and had an average width of 296\,km. We emphasize the vital roles of persistent rising loops and/or mini-filaments in producing recurrent jets by interacting with the fan-like structure, and show their detailed dynamics with unprecedentedly-high-resolution observations.

Figures (4)

• Figure 1: Overview of the region of interest. (a) The whole field of view of EUI at 20:27:24 UT. The red rectangle encircles the region we studied. (b) The zoomed-in snapshot of the region in red rectangle at the same time. The snapshot in (b) is rotated 90 degrees counter-clockwise. The red dashed rectangle in (b) marks the region used to produce the animation. (c) The relative position of the Sun, Earth and SolO. The evolution of the studied region (marked by red dashed rectangle in (b)) from 19:59:56 UT to 23:55:08 UT can be found in the associated animation. The black arrows in the animation point to the structures associated with trigger processes of the jets and the white arrows in the animation mark the jets.
• Figure 2: The snapshots of the region of interest taken by EUI at 20:02:20 UT, 20:06:36 UT, 20:08:44 UT, 20:09:32 UT, 20:40:44 UT, 22:18:52 UT, 22:26:36 UT and 22:29:32 UT. The dashed lines in (a) - (f) show the slits along which we obtain the intensity distributions. The black arrows in (d) & (f) point to the ejected threads originating from the bright blobs and parallel to the jets. The black arrows in (g) & (h) point to the boomerang-like structures at the outflow region of the reconnection. Panels (a1) - (f1) show the intensity distribution along the slits in (a) - (f) respectively. All the snapshots are rotated 90 degrees counter-clockwise as same as Figure \ref{['fig:ove']} (b).
• Figure 3: Evolution of "jet5". (a) - (s) The snapshots of EUI at 20:17:32 UT, 20:19:40 UT, 20:20:28 UT, 20:20:44 UT, 20:21:00 UT, 20:21:16 UT, 20:21:32 UT, 20:21:48 UT, 20:22:52 UT, 20:23:56 UT, 20:24:28 UT 20:25:00 UT, 20:25:16 UT, 20:25:48 UT, 20:26:04 UT, 20:26:52 UT, 20:28:28 UT, 20:29:00 UT and 20:29:16 UT. The blue and red dashed lines in (a) outline two sheared arcades. The green dashed line "S1" in (a) shows the trajectory where we make the time-distance plot shown in (t). The black and white arrows in (b) point to the outflow and post-reconnected loops. The black arrows in (c) - (g) marked with "filament" points to the rising mini-filament. The black arrows in (e) - (h) marked with "thread1" and "thread2" point to different threads of the rising mini-filament and the blue arrow in (h) points to the brightening at the top of the fan-like structure. The red dashed line "S2" in (h) shows the trajectory where we obtain the time-distance plot shown in (u). The black arrows in (i) - (j) point to the contracted threads. The black arrows marked with "filament" in (k) - (p) point to the newly-formed mini-filament. The black arrows marked with "brightening" in (m) and (n) point to the brightenings at the bottom of the jet. The black arrows marked with "ejection" in (m) - (s) point to the ejections originating from the brightenings. The red arrows in (q) and (s) point to the structures at the bottom of the ejections. (t) and (u) show the time-distance plots along "S1" and "S2". All the snapshots are rotated 90 degrees counter-clockwise as same as Figure \ref{['fig:ove']} (b).
• Figure 4: Evolution of "jet18". Panels (a) - (j) show the snapshots of EUI at 22:22:20 UT, 22:23:08 UT, 22:23:24 UT, 22:23:40 UT, 22:23:56 UT, 22:24:12 UT, 22:24:44 UT, 22:25:00 UT, 22:26:36 UT and 22:27:24 UT. The black rectangles in all panels show the region where we enlarged. The black arrow in (a) points to the first rising loop. The black arrows in (b) - (e) point to the first and second rising loops. The green dashed line "S3" in (c) shows the trajectory where we make the time-distance plot shown in (k). The blue arrows in (d) & (f) point to the brightenings occurred when the rising loops encountered the fan-spine-like structure. The red arrows in (d) - (f) point to the brightening near the rising loop. The black arrows marked with "thread" in (e) & (f) point to the thread that appeared during the brightening. The black arrows marked with "nloop1" and "nloop2" in (f) & (g) point to loops that appeared during the brightening. The red line in (f) shows the trajectory of the second rising loop. The white arrow in (f) points to "jet17". The black arrows in (h) & (i) marked with "loop" point to the post-reconnected loops. The green arrows in (g) - (i) point to the bright thin sheet which may be the flare current sheet in breakout model. The white arrows in (g) - (i) point to "jet18". The black arrows marked with "arcade" in (i) & (j) point to contracted arcade under the FCS. The red dashed line "S4" in (j) shows the trajectory where we make the time-distance plot shown in (l). Panels (k) - (l) show the time-distance plots along "S3" and "S4". All the snapshots are rotated 90 degrees counter-clockwise as same as Figure \ref{['fig:ove']} (b).