One Difficulty with the Density Wave Theory Is That

question 142

Multiple Choice

One difficulty with the density wave theory is that

• A) the theory fails to explain why a given spiral pattern lasts only a small fraction of the lifetime of a galaxy.
• B) the theory fails to provide a mechanism for star formation.
• C) astronomers are unsure of the mechanism that produces the energy output necessary to sustain the density wave.
• D) the theory fails to explain the distribution of Population I and Population II stars in the galaxy.

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