Patchy Reconnection in a Y-Type Current Sheet

TL;DR

This paper models the evolution of magnetic fields in a Y-type current sheet following localized reconnection, explaining observed coronal downflows as retracted reconnected magnetic fields.

Contribution

It provides a simulation-based explanation for the behavior of post-CME downflows, linking localized reconnection to observed coronal phenomena.

Findings

Reconnection produces upward and downward flux tubes.

Downward flux tubes decelerate upon hitting Y-lines and arcade loops.

Simulation results support the retraction hypothesis for coronal downflows.

Abstract

We study the evolution of the magnetic field in a Y-type current sheet subject to a brief, localized magnetic reconnection event. The reconnection produces up- and down-flowing reconnected flux tubes which rapidly decelerate when they hit the Y-lines and underlying magnetic arcade loops at the ends of the current sheet. This localized reconnection outflow followed by a rapid deceleration reproduces the observed behavior of post-CME downflowing coronal voids. These simulations support the hypothesis that these observed coronal downflows are the retraction of magnetic fields reconnected in localized patches in the high corona.