Spiral structure can be triggered in a disk galaxy by:
A) the merger of close binary stars
B) a supernova explosion
C) the presence of an active nucleus
D) the gravity of distant galaxies
E) any disturbance to the disk

Question

Quizplus · Accepted Answer

Spiral structure in a disk galaxy can be triggered by any disturbance to the disk, such as the gravitational influence of neighboring galaxies or interactions with gas clouds. These disturbances can cause density waves that propagate through the disk, resulting in the formation of spiral arms. While supernova explosions and the presence of an active nucleus can also affect the behavior of the gas and stars in a disk galaxy, they are not the primary triggers for spiral structure. The merger of close binary stars is not likely to produce the necessary disturbances to generate spiral arms.

Spiral Structure Can Be Triggered in a Disk Galaxy By