Peristaltic Pumping near Post-CME Supra-Arcade Current Sheets

TL;DR

This paper proposes a model where reconnected flux tubes in solar flares induce plasma flows via peristaltic pumping, explaining observed heating and density changes near current sheets.

Contribution

It introduces a novel mechanism of plasma transport through peristaltic pumping caused by flux tube retraction, extending understanding of plasma dynamics in solar flares.

Findings

Peristaltic pumping can generate shocks in unreconnected field regions.

The model explains high temperatures near current sheets in solar flares.

Plasma flows can cause density depletions and downflows observed in the corona.

Abstract

Measurements of temperature and density near supra-arcade current sheets suggest that plasma on unreconnected field lines may experience some degree of "pre-heating" and "pre-densification" prior to their reconnection. Models of patchy reconnection allow for heating and acceleration of plasma along reconnected field lines but do not offer a mechanism for transport of thermal energy across field lines. Here we present a model in which a reconnected flux tube retracts, deforming the surrounding layer of unreconnected field. The deformation creates constrictions that act as peristaltic pumps, driving plasma flow along affected field lines. Under certain circumstances these flows lead to shocks that can extend far out into the unreconnected field, altering the plasma properties in the affected region. These findings have direct implications for observations in the solar corona, particularly in regard to such phenomena as high temperatures near current sheets in eruptive solar flares and wakes seen in the form of descending regions of density depletion or supra-arcade downflows.