The Lyman-α line from the solar wind acceleration region: Results from an eight-moment approximation two-fluid solar wind model



We investigate neutral hydrogen in an eight-moment, two-fluid, high speed solar wind model. In this model the proton heat flux decreases rapidly in the solar wind acceleration region, and extended coronal heating of the proton gas leads to high coronal proton temperatures and large solar wind flow speeds. The properties of the Lyman-α line from the neutral hydrogen in two such models are studied. We show that the temperature maximum in the corona inferred from the observed Lyman-α line may be more than 20% lower than the proton temperature maximum.