2006MNRAS.366..557V

In this paper, an attempt is made to integrate the propeller ejection of material by the fast rotating white dwarf in AE Aquarii with the highly transient thermal and non-thermal emission in a single unifying model. It has been shown that the violent interaction between the fast rotating magnetosphere and a clumpy fragmented stream, in AE Aquarii specifically, may result in the growth of unstable modes of the Kelvin-Helmholtz instability and associated turbulence over length scales comparable to the stream radius on time-scales τ_K–H∼t_dyn(∼ 600s). For all conversion efficiencies of magnetohydrodynamic (MHD) power to mechanical energy ε≥ 0.1, these instabilities result in the effective azimuthal acceleration of the gas parcels to the escape velocity over time-scales t_acc≤ 1000 s (∼t_dyn). Further, it has been shown that the turbulence in the flow will cascade down to the dissipative level over time-scales τ_cas∼ 3 h. If released through dissipative shocks, this reservoir can drive a luminosity of L∼ 10³³erg/s, which can significantly contribute to the total emission when blobs collide in the exit stream, resulting in shock heating and associated flares. During the propeller process, particles can also be accelerated to high energies, which may be the driving mechanism behind the non-thermal radio to mid-infrared emission. The confluence of these ejected magnetized clouds may result in radio remnant surrounding AE Aquarii, which is optically thin between frequencies ν≥ 100 MHz-1 GHz.