Nonradial and nonpolytropic astrophysical outflows. VII. Fitting ULYSSES solar wind data during minimum

Christophe Sauty (1) , J. J. G. Lima (2) , Nicolas Iro (3, 4) , K. Tsinganos (5)

1 LUTH (UMR_8102) - Laboratoire Univers et Théories
2 Universidade do Porto = University of Porto
3 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
4 Pôle Planétologie du LESIA
5 IASA and Section of Astrophysics, Astronomy, and Mechanics, Department of Physics, University of Athens

Exact axisymmetric analytical solutions of the governing MHD equations for magnetized and rotating outflows are applied to the solar wind during solar minimum as observed by ULYSSES. Using the spacecraft data, the latitudinal dependences of physical quantities such as the density, velocity, magnetic field and temperature are analytically described. The self-similar solutions are then compared to the global structure of the wind from one solar radius to 5 AU and beyond, including consistently the rotation of the outflow. The model makes it possible to describe the initial flaring of the magnetic dipolar structure, reproducing in a satisfactory way the observed profiles of the velocity, density and temperature with heliocentric distance. Finally, this model is in agreement with the conjecture that the solar wind should not be collimated at large distances, even close to its rotational axis.

Domaines: Astrophysique [astro-ph]

Christophe Sauty, J. J. G. Lima, Nicolas Iro, K. Tsinganos. Nonradial and nonpolytropic astrophysical outflows. VII. Fitting ULYSSES solar wind data during minimum. Astronomy and Astrophysics - A&A, 2005, 432, pp.687-698. ⟨10.1051/0004-6361:20041606⟩. ⟨hal-03786270⟩