Which factor is essential to the initial formation of galaxies, for either of the theories describing galaxy evolution?(1 point)
The factor essential to the initial formation of galaxies, according to both theories describing galaxy evolution, is the presence of dark matter.
Which factor is essential to the initial formation of galaxies, for either of the theories describing galaxy evolution?(1 point)
Responses
Gravity acts on existing material, shaping it into a new form.
Gravity acts on existing material, shaping it into a new form.
Massive gas and dust clouds collapse.
Massive gas and dust clouds collapse.
The force of orbiting stars generates collisions.
The force of orbiting stars generates collisions.
Small lumps of material merge into larger clumps.
Massive gas and dust clouds collapse.
With which type of galaxy is a small galaxy most likely to merge? Select the two correct answers.(1 point)
Responses
an equal-sized galaxy
an equal-sized galaxy
a nearby galaxy
a nearby galaxy
a fast-moving galaxy
a fast-moving galaxy
a much larger galaxy
a nearby galaxy and a much larger galaxy
Which characteristics are considered most typical of an old galaxy in decline?(1 point)
Responses
very bright, relatively small
very bright, relatively small
shrinking in size, high dust content
shrinking in size, high dust content
spiral, abundant planets present
spiral, abundant planets present
low gas content, little star formation