A cluster of galaxies refers to a structure in which multiple galaxies come together by gravitational interaction in the universe.
In the universe, galaxies do not exist in isolation, they tend to form clusters of galaxies of various sizes in different ways.
A cluster of galaxies is usually made up of tens to thousands of galaxies that are gravitationally attracted to each other and kept within a smaller area.
Clusters of galaxies
The scale of galaxy clusters is usually between millions and tens of millions of light-years.
In a cluster of galaxies, the gravitational interaction between galaxies causes them to move relative to each other in a common gravitational field.
These relative motions affect the velocity and position of galaxies, forming specific structures.
Some galaxies may be at higher velocities and relative positions, while others may be more stationary.
This distribution of velocity and position forms the dynamical characteristics of galaxy clusters.
There may be some other interactions between galaxies in a galaxy cluster, such as collisions between galaxies, the influence of tidal forces, etc.
These interactions can alter the morphology of galaxies, the distribution of stars within galaxies, and the exchange of gas and matter between galaxies.
By studying galaxy clusters, astronomers can gain insight into the formation and evolution of the structure of the universe.
Observations of galaxy clusters can provide important information about the distribution of dark matter, the rate of expansion of the universe, and cosmological parameters.
The study of galaxy clusters also contributes to the understanding of the mechanisms of galaxy formation and evolution, as well as the interactions and merger processes between galaxies.
Superclusters
Star clusters can be divided into two main types: globular clusters and open clusters.
The stars in globular clusters are dense and closely connected, forming a relatively stable cluster structure.
They usually do not have significant flatness or elliptical shape, and the star density is very high, which results in close proximity between the stars.
This in turn makes globular clusters appear like a bright spot in the sky, rather than individual stars.
Most globular clusters are relatively ancient structures that form in the core region of the Milky Way or in the galactic halo.
They are usually between billions and tens of billions of years old.
The stellar composition of globular clusters is generally more consistent.
This means that their stars have similar ages, chemical compositions, and evolutionary histories.
It turns out that these stars often appear suddenly during the same nebula or cluster formation event.
The stars in globular clusters are usually ancient stars that form lions before other stars.
The gravitational interaction between the stars inside globular clusters allows them to exist in a relatively stable state.
This means that the stars in globular clusters usually remain in a relatively stationary position and do not undergo violent interactions or collisions for a short period of time.
Globular clusters are very interesting and important structures in astronomy, and they provide valuable information for studying star formation, evolution, and the structure of the Milky Way.
By observing the characteristics and distribution of stars in globular clusters, astronomers can understand the nature of star populations, the laws of stellar evolution, and the dynamics of the central region of the Milky Way.
Open clusters are loose structures made up of relatively young stars, often containing tens to thousands of stars.
These star clusters are usually formed in nebulae and are formed due to gravitational collapse.
The interaction between the stars of the open cluster is weak, and they remain relatively stable in the universe for a relatively short period of time.
Open clusters are loose structures made up of relatively young stars, usually containing tens to thousands of stars, which are smaller than globular clusters.
They have a relatively small number of stars, but still form a relatively dense cluster structure.
The stars in the Open Cluster are generally made up of the same nebula, so they are also relatively close in age.
Open star clusters are generally relatively young, typically millions to billions of years old.
Stars in open clusters often have different ages and chemical compositions.
They may have formed in the same nebula, but the formation time may be different, so the stars in the cluster can show different stages of evolution.
Internal media
The internal medium of galaxies mainly consists of gas, stars, interstellar medium, and dark matter.
There is a large amount of gas inside galaxies, mainly composed of hydrogen and other elements.
In the Milky Way, this gas is called an "interstellar cloud", and some of them occur in the universe, such as when stars are formed, and they explode in the universe.
Interstellar dust is a substance composed of tiny particles that scatter and absorb starlight, acting as a shield and shield.
Interstellar matter also includes interstellar magnetic fields and energetic particles in the interstellar medium, among others.
Dark matter does not interact with electromagnetic radiation, so it cannot be directly observed.
However, through the observation of galaxy rotation curves, gravitational lensing effects, and large-scale structures, scientists speculate that there is a large amount of dark matter inside galaxies, which plays an important role in stabilizing the gravitational pull of galaxies.
Stellar distribution
The star distribution of galaxies can take many forms, depending on the type of galaxy and its evolutionary history.
Many galaxies have disk-like structures in which the stars are mostly distributed in a flat disk.
This form of distribution is most common in spiral galaxies, such as our Milky Way.
In the disk of galaxies, the density of stars gradually decreases as the center of the disk increases.
The center of a galaxy is usually a dense region called a galaxy nucleus.
In the nucleus of galaxies, the density of stars is higher and one or more supermassive black holes may be present.
The distribution of stars near the nucleus of galaxies may be more concentrated and compact.
A galactic halo is an outer region of a galaxy and is usually a relatively sparse distribution of stars, with a low density of stars in a galactic halo and a large distance between stars.
Stars in galactic halos may have been formed by the merger of some earlier star clusters or other galaxies.
Some galaxies may not have significant symmetry in their star distribution.
In galaxies, the gravitational pull between star clusters, the interaction force between stars, is always present.
In addition, these forms of stellar distribution are not absolute, and different types of galaxies may have different stellar distribution characteristics. The stellar distribution of galaxies may also be influenced by dynamical processes within galaxies, galaxy evolution, and environmental factors.