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. Small lumps of material merge into larger clumps. Small lumps of material merge into larger clumps. The force of orbiting stars generates collisions. The force of orbiting stars generates collisions.
Massive gas and dust clouds collapse.
Which characteristics are considered most typical of an old galaxy in decline?(1 point) Responses shrinking in size, high dust content shrinking in size, high dust content very bright, relatively small very bright, relatively small spiral, abundant planets present spiral, abundant planets present low gas content, little star formation
shrinking in size, high dust content low gas content, little star formation
With which type of galaxy is a small galaxy most likely to merge? Select the two correct answers.(1 point) Responses a nearby galaxy a nearby galaxy a much larger galaxy a much larger galaxy a fast-moving galaxy a fast-moving galaxy an equal-sized galaxy
a nearby galaxy a much larger galaxy
The factor essential to the initial formation of galaxies, according to either of the theories describing galaxy evolution, is: Massive gas and dust clouds collapse.
The correct answer is: Massive gas and dust clouds collapse.
To understand why this answer is correct and how it relates to the theories describing galaxy evolution, we need to understand the process of galaxy formation.
According to the prevailing theories of galaxy formation, galaxies form from the gravitational collapse and subsequent cooling of enormous clouds of gas and dust. These clouds contain primordial material left over from the early universe.
Under the influence of gravity, these massive clouds of gas and dust begin to collapse. As the cloud collapses, it starts to spin faster due to the conservation of angular momentum. This spinning motion causes the material to flatten into a rotating disk-like structure, known as a protogalactic disk.
The continued collapse of the gas and dust within the protogalactic disk leads to the formation of more and more concentrated regions called stellar nurseries. In these nurseries, the gas and dust further condense, eventually forming stars.
Over time, these newly formed stars cluster together, merging with other small clumps of material in the process. This merging of small lumps into larger clumps is indeed another factor involved in galaxy formation. However, it is not as essential as the initial collapse of massive gas and dust clouds.
While the force of orbiting stars and the resulting collisions can play a role in shaping galaxies and influencing their evolution, it is not as fundamental as the collapse of massive gas and dust clouds in the early stages of galaxy formation.