Soft X-Ray Imaging of Magnetopause Reconnection Outflows Under Low Plasma-$\beta$ Solar Wind Conditions

TL;DR

This study uses simulations to analyze soft X-ray emissions from Earth's magnetopause during reconnection events, especially under low plasma-beta conditions, revealing how X-ray intensity reflects plasma outflows.

Contribution

It demonstrates that low plasma-beta solar wind conditions enable visualization of mesoscale magnetopause reconnection sites via X-ray emissions.

Findings

X-ray emission brightness reaches ~6 x 10^{-6} eV cm^{-3} s^{-1} during reconnection.

X-ray intensity correlates with plasma outflows under low plasma-beta conditions.

Simulation results suggest potential for observing reconnection sites in the solar corona.

Abstract

We examined soft X-ray emission by the solar wind charge-exchange process around the Earth's magnetosphere using a global magnetohydrodynamic simulation model. The dayside magnetopause reconnection heats and accelerates the plasma whereby the X-ray emission becomes as bright as $\sim 6 \times 10^{-6} {\rm\ eV}\ {\rm cm}^{-3}\ {\rm s}^{-1}$ under the southward interplanetary magnetic field conditions. In particular, under low plasma-$\beta$ solar wind conditions, we found that the X-ray intensity reflects the bulk motion of outflows from the reconnection region. We propose that this particular solar wind condition would allow visualization of the mesoscale magnetopause reconnection site, as observed in the solar corona.