how are the bars in barred spiral galaxies thought to have formed?
a. slow evolution
b. separation
c. merging
d. primordial collapse
c. merging
which factors are more likely to affect whether a galaxy will evolve by merging with another galaxy? Select two correct answers.
a. its proportion of gas compared to that of the other galaxy
b. its age compared to that of the other galaxy
c. its distance from the other galaxy
d. its size compared to that of the other galaxy
a. its proportion of gas compared to that of the other galaxy
d. its size compared to that of the other galaxy
Under the influence of gravity, over time the dense central part of the galaxy will do what?
a. stay as it is, forces balanced
b. stay the same size but spin more slowly
c. contract
d. expand
c. contract
How do astronomers know about the future collision of Andromeda and the Milky Way?
a. The Milky Way has changed course to head toward Andromeda
b. The two galaxies have collided previously
c. All galaxies will collide at some point
d. Astronomers have observed their movements over time
d. Astronomers have observed their movements over time
Which is a mark of a galaxy formed by collapse?
a. uniformly young stars
b. same age stars
c. abundant gas and dust
d. a mix of young and old stars