What mechanism transforms a minor density fluctuation into a much larger trailing wave pattern?
Answer
Swing Amplification
Maintaining global spiral waves against dissipative effects requires mechanisms capable of sustaining and growing initial disturbances over billions of years. Swing Amplification is a proposed mechanism that addresses this need. It demonstrates how a small, pre-existing density fluctuation within the stellar disk, when subjected to the combined effects of differential rotation and the epicyclic motion inherent to the orbits, can be effectively amplified. This process transforms the initial small perturbation into a much larger, pronounced, trailing wave pattern that can then propagate through the disk.
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