It is highly improbable that clusters of galaxies have been built up by chance encounters of galaxies in the general field. It just takes too long (longer than the age of the universe) to complete the process. Therefore, either that clusters are systems whose member galaxies became gravitationally bound at more or less the same time, or that the clusters represent condensations from pregalaxian material and that subcondensations within them became galaxies.
The shape of a group of galaxies can vary greatly depending on the number and distribution of galaxies within the group. Some may have a more spherical shape, while others may have a more elongated or irregular shape.
The shapes of galaxies within a group are determined by their interactions with one another, as well as the gravitational forces acting on them. Over time, these interactions can cause galaxies to change shape and merge with one another.
No, groups of galaxies can have a wide range of shapes and sizes. Some may contain mostly spiral galaxies, while others may have mostly elliptical galaxies. The shape of a group can also change over time as galaxies continue to interact and merge.
The shape of a group of galaxies can affect their evolution in a number of ways. For example, the shape can determine the rate at which galaxies merge and form new stars, which can impact the overall growth and development of the group.
Yes, the shape of a group of galaxies can change over time as galaxies continue to interact and merge. In fact, the shape of a group can be used as an indicator of its age, with younger groups typically having a more irregular shape compared to older, more mature groups.