If spiral density waves were the only thing producing spiral arms,what result would be expected?
A)All spiral arms would be gas- and dust-free.
B)All galaxies would have only two smooth spiral arms.
C)The Milky Way would show an irregular pattern of short arms.
D)The halo component of the Milky Way would show spiral arms as well.

Question

Quizplus · Accepted Answer

If spiral density waves were the only thing producing spiral arms, then galaxies would have only two smooth spiral arms. This is because the number and shape of the arms would be determined solely by the properties of the density waves, which are typically observed to have two arms in simulations.

If Spiral Density Waves Were the Only Thing Producing Spiral