Fig. 3
From: Density response to magnetic field fluctuation in the foreshock plasma
Slope of the linear relation between the density fluctuation and the squared magnetic field fluctuation plotted as a function of the beta-tilde parameter (\(\tilde{\beta }= c_{\mathrm {s}}^2/V_{\mathrm {A}}^2\)). The slope is evaluated using the density fluctuation and the total magnetic field fluctuation (including both linear fluctuations and nonlinear fluctuations) by subtracting by the mean magnetic field, \(\delta B_{\mathrm {t}}^2 = B^2 - B_0^2\). The slope values are derived from the least square fitting: single response group in black, separate response group in diamond and gray, and overlapped response group in triangle and gray. Error bars indicated three-sigma for a confidence interval of about 95% both in the beta-tilde parameter and the slope estimates