Fig. 4
From: Nonlinear wave growth theory of whistler-mode chorus and hiss emissions in the magnetosphere
Linear dispersion relation. Linear dispersion relation of a plasma consisting of cold electrons, cold ions, and minor hot electrons (\(n_{\text{h}}/n_{\text{c}} = 2\times 10^{-3}\)). A subtracted Maxwellian for the energetic electrons is assumed with \(\beta = 0.3\), \(\rho = 1.0\), \(U_{t \parallel } = 0.25 c\), and \(U_{t \perp } = 3.0 c\). The frequencies and linear growth rates for different wave normal directions \(\theta =\) 0, 15, 30, 45, 60, 75 degrees are shown in the same colors, respectively