Fig. 4

a Temperature anisotropy (T_⊥/T_∥ − 1, where T_⊥ and T_∥ are the perpendicular and parallel temperature), b the ratio between the electron plasma frequency (f_pe) and the electron cyclotron frequency (f_ce), c the ratio between the hot electron density (N_H) and the cold electron density (N_c), d the cold electron density in the equatorial plane, e the magnitude of the magnetic field, and f the gradient of the magnetic field along a field line at T = 169 min (2:49). The Sun is to the left