AN ANALYTICAL MODEL FOR RECONNECTION OUTFLOW JETS INCLUDING THERMAL CONDUCTION

We develop a model that predicts the velocity, density, and temperature of coronal reconnection jets in the presence of thermal conduction. Our model is based on the quasi-one-dimensional treatment of reconnecting current sheets developed by B. Somov and V. S. Titov using the magnetohydrodynamics nozzle equations. We incorporate thermal conduction into the Somov-Titov framework using slow-shock jump conditions modified to include losses due the conduction of thermal energy along field lines mapping to the chromosphere. We find that thermal conduction has a significant effect on the fast-mode Mach number of the reconnection outflow, producing Mach numbers possibly as high as 7 for some solar-flare conditions. This value is three times greater than previously calculated. We conclude that these termination shocks are considerably more efficient at producing particle acceleration than previously thought since the efficiency of particle acceleration at shocks increases dramatically with Mach number. We compare this model with numerical simulations by T. Yokoyama and K. Shibata and find good agreement.