Characterization of the slow wind in the outer corona

TL;DR

This paper analyzes the slow solar wind in the outer corona during solar cycle 22 minimum, using UV spectroscopy and magnetic modeling to identify its source regions along streamer boundaries.

Contribution

It combines spectroscopic data with 3D magnetic models to precisely locate the origins of the slow solar wind in the corona.

Findings

Slow wind sources are confirmed along streamer boundaries.

Spectroscopic analysis infers plasma parameters in the extended corona.

Magnetic topology helps define the source regions.

Abstract

The study concerns the streamer belt observed at high spectral resolution during the minimum of solar cycle 22 with the Ultraviolet Coronagraph Spectrometer (UVCS) onboard SOHO. On the basis of a spectroscopic analysis of the O VI doublet, the solar wind plasma parameters are inferred in the extended corona. The analysis accounts for the coronal magnetic topology, extrapolated through a 3D magneto-hydrodynamic model, in order to define the streamer boundary and to analyse the edges of coronal holes. The results of the analysis allow an accurate identification of the source regions of the slow coronal wind that are confirmed to be along the streamer boundary in the open magnetic field region.