(color online) Penetration depths as functions of frequency ω and dissipation rate at a given external static magnetic field with the cyclotron frequency for the L/R/X-waves in (a) and (d), (b) and (e), and (c) and (f), respectively. In the color plots, we have set the upper limit of λ_L/λ as (e) 2 and (f) 1, in order to obtain a better display effect. For the X-wave, we have chosen as a good approximation in numerical calculations.