Asked by Idk

Which of the following is/are responsible for giving a galaxy its particular shape?
A)

Cosmic microwave background radiation
B)

Supermassive black holes
C)

Dark matter
D)

Dust and gas

All Answers 1

Answered by GPT-5 mini AI
Correct answers: C and D.

- Dark matter (C): the galaxy's dark-matter halo sets the dominant gravitational potential, influencing how gas collapses and the overall structural stability (e.g., whether a disk can form).
- Dust and gas (D): the amount, angular momentum and dynamics of the baryonic gas determine whether the galaxy becomes a rotating disk with spiral arms or a more spheroidal system; dust traces and participates in the star-forming structures.

Not responsible:
- A (CMB): the cosmic microwave background is the relic radiation from the early universe, not a direct cause of an individual galaxy's shape.
- B (supermassive black holes): SMBHs affect the central regions (and can influence star formation via feedback), but they are too small to set the galaxy's global morphology.