Early on, after matter had gained dominance over radiation, there was little more than dispersed, if massive, gas and dust clouds.These gas clouds then began condensing to form the early galaxies known as quasar galaxies.Models have shown that the Magellanic Clouds are destined to merge with the Milky Way because the force of gravity will cause them to collide.
A large gas cloud could have fragmented into smaller condensing regions of many different sizes, some yielding the larger elliptical galaxies and some yielding the comparatively small irregular galaxies, depending on the size and mass of the initial condensing region.
This evidence, therefore, is not singularly beneficial to the bottom-up model of the universe.
After all, if nature exhibits certain behaviors in not one but two major areas of astronomy, who is to say that the same cannot ring true for galaxies?
That being said, there are convincing pieces of evidence that favor the bottom-up model.
They then grew by merging with other galaxies in close proximity through mutual gravitational attraction.
The Hubble Space telescope is able to see galactic mergers that provides strong evidence for this phenomenon.If you notice the same thing, switch to something really hot!The origin of galaxies has remained such an unsolvable mystery because technology has not yet progressed to such a point that it can satisfactorily answer this question.Therefore, some other component must have been in effect to accelerate the process of galaxy formation.This “something” is theorized to be dark matter, a classification of matter which astronomers have only been able to detect by its gravitational effects on the cosmos.However, computer simulations running this event showed that there was not enough time for the galaxies to form given the age of the universe, which is postulated to be around 12 billion years old.