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abstraction > hypothesis > theory > astronomy theory > galaxy theory > spiral density wave

spiral density wave comparison table

Subject	is a kind of	has definition
galaxy theory	astronomy theory
spiral density wave	galaxy theory	A wave, due to a local increase in the gravitational field, that produces a series of alternate compressions and rarefactions as it propagates with fixed angular velocity in a rotating galaxy. The compression also acts on interstellar gas in the galaxy, which is triggered to form stars on the leading edges of the spiral arms. The large-scale structure of spiral galaxies can be understood in this way.

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