How are galaxies made?

By Mohammad Zahedinejad, On 28th January 2021, Under Science and Education
Astronomers aren't certain exactly how galaxies formed. After the Big Bang, space was made up almost entirely of hydrogen and helium. Some astronomers think that gravity pulled dust and gas together to form individual stars, and those stars drew closer together into collections that ultimately became galaxies.

People also ask, how do galaxies work?

A galaxy is a large system of stars, gas (mostly hydrogen), dust and dark matter that orbits a common center and is bound together by gravity -- they've been described as "island universes." Galaxies come in many sizes and shapes.

Beside above, what are the 4 types of galaxies?

In 1936, Hubble debuted a way to classify galaxies, grouping them into four main types: spiral galaxies, lenticular galaxies, elliptical galaxies, and irregular galaxies. More than two-thirds of all observed galaxies are spiral galaxies.

How many galaxies are in the universe?

100 billion galaxies

What galaxy do we live in?

the Milky Way
Zombie galaxy
Hubble observations of the distant galaxy reveal that it hasn't made stars for some 10 billion years. MACS 2129-1 is what's known as a "dead galaxy," because stars no longer form there. The discovery of this galaxy was a head-scratcher.
The Milky Way is a large spiral galaxy. Earth is located in one of the spiral arms of the Milky Way (called the Orion Arm) which lies about two-thirds of the way out from the center of the Galaxy.
The Milky Way is big, but some galaxies, like our Andromeda Galaxy neighbor, are much larger. The universe is all of the galaxies – billions of them! Our Sun is one star among the billions in the Milky Way Galaxy.
Stars are like nuclear reactors. They take a fuel and convert it to something else. Hydrogen is formed into helium, and helium is built into carbon, nitrogen and oxygen, iron and sulfur—everything we're made of. So most of the material that we're made of comes out of dying stars, or stars that died in explosions.
The closest known galaxy to us is the Canis Major Dwarf Galaxy, at 236,000,000,000,000,000 km (25,000 light years) from the Sun. The Sagittarius Dwarf Elliptical Galaxy is the next closest , at 662,000,000,000,000,000 km (70,000 light years) from the Sun.
Stars shine by thermonuclear burning of the gas; of those that die in explosions, some blow the gas back out of the galaxies. In time, any given galaxy begins to run out of recyclable gas. Without gas, it can't form new stars; the old stars live out their lives and die, and eventually the galaxy dies too.
The multiverse. If we define "universe" as "all there is" or "all that exists," then obviously, by definition, there can be only one universe. But if we define "universe" as "all we can ever see" (no matter how large our telescopes) or "space-time regions that expand together," then many universes may indeed exist.
Galaxy origins
Gravity had sculpted the first galaxies into shape by the time the universe turned 400 million years old, or less than 3 percent of its current age. Astronomers now think that nearly all galaxies—with possible exceptions—are embedded in huge haloes of dark matter.
13.7 billion years
What is the Universe made of? The Universe is thought to consist of three types of substance: normal matter, 'dark matter' and 'dark energy'. Normal matter consists of the atoms that make up stars, planets, human beings and every other visible object in the Universe.
Composition. The universe is composed almost completely of dark energy, dark matter, and ordinary matter. Other contents are electromagnetic radiation (estimated to constitute from 0.005% to close to 0.01% of the total mass-energy of the universe) and antimatter.
Bottom line: The sun is about 1/3 the distance from the center of the Milky Way galaxy to its outer edges. It's located in a smaller spiral arm, between two large arms, called the Orion Arm.
One gets a rough idea of the shape of the Milky Way galaxy by just looking around--a ragged, hazy band of light circles the sky. That observation indicates that our Milky Way Galaxy is a flattened disk of stars, with us located somewhere near the plane of the disk. Were it not a flattened disk, it would look different.
According to the current understanding of physics, an object within space-time cannot exceed the speed of light, which means an attempt to travel to any other galaxy would be a journey of millions of earth years via conventional flight.
It was from density fluctuations (or anisotropic irregularities) in this primordial matter that larger structures began to appear. As a result, masses of baryonic matter started to condense within cold dark matter halos. These primordial structures would eventually become the galaxies we see today.
Galaxies come in many sizes. The Milky Way is big, but some galaxies, like our Andromeda Galaxy neighbor, are much larger. The universe is all of the galaxies – billions of them!
When the galaxies collide, it causes vast clouds of hydrogen to collect and become compressed, which can trigger a series of gravitational collapses. A galaxy collision also causes a galaxy to age prematurely, since much of its gas is converted into stars.
Answer: Yes, you can see a few other galaxies without using a telescope! The nearby Andromeda Galaxy, also called M31, is bright enough to be seen by the naked eye on dark, moonless nights. The Andromeda Galaxy is the only other (besides the Milky Way) spiral galaxy we can see with the naked eye.
Galaxies also change over time. The Milky Way is on a collision course with the nearby Andromeda Galaxy, and both will merge in about 4 billion years. Later on, other galaxies in our Local Group — the galaxies closest to us — will eventually combine.