Fine Magnetic Structure and Origin of Counter-Streaming Mass Flows in a Quiescent Solar Prominence

TL;DR

This study uses high-resolution observations to analyze the magnetic structure and dynamics of a quiescent solar prominence, revealing the role of magnetic reconnection and pressure imbalance in counter-streaming mass flows.

Contribution

It provides a detailed magnetic topology model of the prominence and links dynamic flows to magnetic reconnection and pressure differences, advancing understanding of prominence stability.

Findings

The prominence consists of a horizontal spine, and vertical and horizontal feet supported by magnetic structures.

Counter-streaming flows are driven by magnetic reconnection and pressure imbalance.

The vertical foot's bubble structure oscillates and is associated with flare-like activity.

Abstract

We present high-resolution observations of a quiescent solar prominence which was consisted of a vertical and a horizontal foot encircled by an overlying spine, and counter-streaming mass flows were ubiquitous in the prominence. While the horizontal foot and the spine were connecting to the solar surface, the vertical foot was suspended above the solar surface and supported by a semicircular bubble structure. The bubble first collapsed and then reformed at a similar height, finally, it started to oscillate for a long time. We find that the collapsing and oscillation of the bubble boundary were tightly associated with a flare-like feature located at the bottom of the bubble. Based on the observational results, we propose that the prominence should be composed of an overlying horizontal spine encircling a low-lying horizontal and a vertical foot, in which the horizontal foot was consisted of shorter field lines running partially along the spine and with the both ends connecting to the solar surface, while the vertical foot was consisted of piling-up dips due to the sagging of the spine fields and supported by a bipolar magnetic system formed by parasitic polarities (i.e., the bubble). The upflows in the vertical foot were possibly caused by the magnetic reconnection at the separator between the bubble and the overlying dips, which intruded into the persistent downflow field and formed the picture of counter-streaming mass flows. In addition, the counter-streaming flows in the horizontal foot were possibly caused by the imbalanced pressure at the both ends.