The physical solution to the Parker model of solar wind has this property and a vanishing pressure at infinity. For 10 points each:
[10m] Name this property of flow that can be achieved with a de Laval nozzle when it is choked at its throat. A description is acceptable.
ANSWER: transonic [or transsonic; or answers that indicate crossing the speed of sound; accept supersonic or answers that indicate going faster than the speed of sound]
[10e] Transonic nozzle flow can be used to analyze the formation of these collimated structures. These structures consist of a beam of plasma accelerated beyond the speed of sound of the surrounding interstellar medium.
ANSWER: astrophysical jets
[10h] Herbig–Haro objects, which are series of knots in jets that originate from young stellar objects, may be associated with these regions in the jet, which are coupled with a bow shock at the working surface. In jet engines, these glowing eponymous regions are associated with the formation of shock diamonds.
ANSWER: Mach disks [prompt on normal shocks; prompt on jet shocks]
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