The paper you mentioned made me harvest Wiki pages.
Plasma Wakefield acceleration
(I love when they get the "Fluid" part right.)A plasma consists of fluid of positive and negative charged particles...
The illustration they use in the Wiki page is what I see happening inside the Sun when it spits out the string of planets. When you scale that up to the size of the Sun you have planets rather than an electron beam emerge. The mention of "Whistler" made me harvest various Wiki pages that mention it.
Electromagnetic electron wave
http://en.wikipedia.org/wiki/Electromag ... ctron_wave
X-rays from lightning
Van Allen radiation belt
When I think of "Whistler" or "whistles" I think of the Cavity Magnetron and how they take low frequency and turn it into high frequency, the same way a toy whistle works.
http://en.wikipedia.org/wiki/Klystron Plasma oscillation
http://en.wikipedia.org/wiki/Whistle It's all Fluid Mechanics, and everything scales up.