Description
The slow solar wind has long been believed to be driven by interchange reconnection between open and closed flux at pseudo and helmet streamers. While recent work now suggests that the Alfvénic fast wind may also be the result of interchange reconnection occurring at a multitude of small, network bipoles inside coronal holes. Here, we present observations of the post-eruption relaxation phase of a large pseudostreamer, as captured by Metis onboard the Solar Orbiter on October 12, 2022, during its perihelion passage. Utilizing total brightness data, we observe the outward propagation of helical features up to 3 solar radii along a radial column that appears to correspond to the stalk of the pseudostreamer. The helical structures persisted for more than 3 hours following a jet-like eruption. A notable trend is revealed: the inclination of these features decreases as their polar angle and height increase. We find that the Metis helical structure may be interpreted as a consequence of twist (nonlinear torsional Alfvén waves) and plasma liberated by interchange reconnection. A comparison was performed of the inclination angle as outlined by fine-scale outflow features with those obtained from synthetic white-light images derived from a high-resolution MHD simulation of interchange reconnection in a jet topology. A remarkable similarity between the simulation derived images and the observations was found. We conclude that these Metis observations represent the upper end in spatial and energy scale of the physical process responsible for the slow and potentially also the fast Alfvénic solar wind.
