A possible mechanism of energy dissipation in the front of a shock wave driven ahead of a coronal mass ejection

TL;DR

This paper investigates the energy dissipation mechanism in CME-driven shock fronts, suggesting that up to 5 solar radii, the dissipation is primarily collisional due to the shock front's thickness being comparable to the proton mean free path.

Contribution

The study provides observational evidence that collisional processes dominate energy dissipation in CME shock fronts within 5 solar radii.

Findings

Shock front thickness is about the proton mean free path up to 5 R_sun.

Energy dissipation mechanism is collisional at these distances.

Supports previous theoretical predictions about shock dissipation mechanisms.

Abstract

Mark 4 and LASCO C2, C3 coronagraph data analysis shows that, up to the distance $R\sim$ 5 R$_\odot$ from the center of the Sun, the thickness of a CME-generated shock front may be of order of the proton mean free path. This means that the energy dissipation mechanism in a shock front at these distances is collisional.