Fig. 8

Phase speed diagram of the observed fluctuations as a function of the phase speeds parallel (the vertical axis) and perpendicular (the horizontal axis) to the large-scale magnetic field. The phase speeds are normalized to the Alfvén speed. The gray curves indicate the phase speeds of the Alfvén mode (inner circles) and the fast most (outer circle). The error bars are shown at the bottom right corner, representing the flow speed variation