MMS data of two events with MHs in the solar wind. The left panels show a MH with LW activity, and the right panels show MH without LW activity. (a and e) Magnetic field components (black, blue, and red) and magnitude (green) in the solar wind around a MH, with the density plotted on the right axis. (b and f) High-resolution electric field, showing LW activity in the MH on the left and little to no LW activity in the MH to the right. (c and g) Reduced electron distribution function around a MH. The velocity component parallel to the magnetic field is on the y-axis. (d and h) Pitch angle distribution at energies close to the strahl component (50−200 eV). The MH with LW activity shows more strahl scattering than the MH without LW activity.