Coronal Pseudostreamers: Source of Fast or Slow Solar Wind?

TL;DR

This paper investigates how the magnetic structure of coronal pseudostreamers influences whether they produce fast or slow solar wind, emphasizing the importance of 3D magnetic expansion factors.

Contribution

It provides a detailed analysis of the magnetic configurations of pseudostreamers and their impact on solar wind speed, highlighting the role of filament channels and complex magnetic expansion.

Findings

Filament channels at pseudostreamer bases lead to slower solar wind.

Expansion factors vary non-monotonically with distance, depending on overall magnetic configuration.

Magnetic field complexity influences solar wind speed from pseudostreamers.

Abstract

We discuss observations of pseudostreamers and their 3D magnetic configuration as reconstructed with potential field source surface (PFSS) models to study their contribution to the solar wind. To understand the outflow from pseudostreamers the 3D expansion factor must be correctly estimated. Pseudostreamers may contain filament channels at their base in which case the open field lines diverge more strongly and the corresponding greater expansion factors lead to slower wind outflow, compared with pseudostreamers in which filament channels are absent. In the neighborhood of pseudostreamers the expansion factor does not increase monotonically with distance from the sun, and doesn't simply depend on the height of the pseudostreamer null point but on the entire magnetic field configuration.