What observational evidence supports the galactic fountain model (which describes how gas cycles between the disk of the galaxy and regions high above the disk)?
A)We have discovered a jet of ionized gas shooting out of the bulge of our galaxy.
B)We have discovered that the entire galactic disk is being uniformly "rained on" by cool gas coming from the halo.
C)We see hot gas high above the region of the disk near our solar system,along with cool gas that appears to be raining down from the halo.
D)We have observed a lot of water molecules in the interstellar medium.

Question

Quizplus · Accepted Answer

The presence of both hot gas high above the disk and cool gas raining down from the halo are direct observations that support the galactic fountain model. Option A refers to a different phenomenon, and option B is not entirely accurate - there are localized regions where cool gas is raining down, but not the entire disk uniformly. Option D is unrelated to the galactic fountain model.

What Observational Evidence Supports the Galactic Fountain Model (Which Describes