What phenomenon is primarily responsible for the persistent appearance of spiral arms in a galactic disk?

Answer

Density waves propagating through the disk

The spiral structure is attributed to density waves moving through the galactic disk. As gas clouds enter these compressed regions, star formation is triggered, making the arms appear bright and defined temporarily.

What phenomenon is primarily responsible for the persistent appearance of spiral arms in a galactic disk?

#Videos

We Can't Explain Spiral Galaxies - The Winding Problem - YouTube

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