The Role of Pressure Anisotropy in Cosmic-Ray Hydrodynamics
Zweibel, Ellen G., The Role of Pressure Anisotropy in Cosmic-Ray Hydrodynamics, ApJ, 890, 67 (2020) (ADS)
(click on the image for a larger version)
A technical cartoon illustrating a calculation of the effects of
cosmic-ray pressure anisotropy.
This is for non-solar applications, of course, since cosmic-ray
pressure does not usually play a structural role in the inner
heliosphere.
But we are still curious about the propagation of
cosmic rays near the Sun,
since these dominate its γ-ray emission at all times, and have
many other interesting properties during
solar particle events.
Here the upper panel shows the distortion of a flux tube with lower
Alfvén speed from a cosmic-ray source to the left.
Generally the heliosphere presents a region of increasing Alfvén speed
as GCRs enter it, but there is considerable structure due to streamers
and active regions that will perturb the "flow" of the cosmic-ray "fluid" -
that's the kind of language that people use, believe it or not.
The perspective representation looks a little bit off here.
The idea was to increase the cosmic-ray pressure in one thin flux tube
(colored) which can then expand into its surrounding flux tubes.
But the top layer of this bundle looks eccentric to the Archivist.
A technical cartoon illustrating a calculation of the effects of cosmic-ray pressure anisotropy. This is for non-solar applications, of course, since cosmic-ray pressure does not usually play a structural role in the inner heliosphere. But we are still curious about the propagation of cosmic rays near the Sun, since these dominate its γ-ray emission at all times, and have many other interesting properties during solar particle events. Here the upper panel shows the distortion of a flux tube with lower Alfvén speed from a cosmic-ray source to the left. Generally the heliosphere presents a region of increasing Alfvén speed as GCRs enter it, but there is considerable structure due to streamers and active regions that will perturb the "flow" of the cosmic-ray "fluid" - that's the kind of language that people use, believe it or not.
The perspective representation looks a little bit off here. The idea was to increase the cosmic-ray pressure in one thin flux tube (colored) which can then expand into its surrounding flux tubes. But the top layer of this bundle looks eccentric to the Archivist.