A young galaxy that shocked astronomers
At the center of each of these frames is a newly discovered bright ultraviolet galaxy discovered by NASA's Galaxy Evolution Probe. (Image credit: NASA/JPL-Caltech/John. Hopkins University)
Astronomers have identified 36 bright, young galaxies that go against the general trend of cosmic aging.
Based on current theory, these galaxies, either very close to us or very large, are younger than they should actually be. They look like toddlers or teenagers who astronomers find when observing galaxies across distant distances, and thus date back to the early universe.
"We know there really were huge young galaxies here tens of thousands of years ago, but we all think they've matured into older galaxies, more like our Milky Way." Principal Investigator chris M. Thompson of NASA's Caltech Galaxy Evolution Probe Martin said, ''If these galaxies are indeed all newly formed, then that means that part of the universe is still a hotbed of galaxy birth.' ‘’
It is not entirely unreasonable that galaxies are still forming. Other investigations have found small galaxies forming. But because the universe has been expanding since its inception, material, once squeezed tightly together at an ideal density of star formation, has spread steadily for 13.7 billion years. Nowadays, it is more difficult to build a large galaxy.
When gas collapses below its own weight, stars form. This gas is usually part of a galaxy that uses its weight to attract gas around it, a process that compresses the gas, and stars are born.
A study earlier in those years estimated that star formation in the universe reached its peak about 5 billion years ago, before the sun was born. At that time, collisions of galaxies were more common than they are now, which is also thought to be the cause of star formation.
The newly discovered galaxy is relatively close, 2 billion to 4 billion light-years away. 1 light-year refers to the distance traveled by light in a year, which is about 6 trillion miles (10 trillion kilometers). If anything were 2 billion light-years away, we would think it existed 2 billion years ago.
Astronomers say tuesday the orbital observatory captured light emitted by the galaxies as early as 100 million to 1 billion years ago. Our Milky Way, a mature galaxy, is at least 10 billion years old.
It's a blessing to find developing galaxies so close, because astronomers are able to observe the structure of these galaxies rather than just see faint light from the universe.
''Now we can study the ancestors of galaxies similar to the Milky Way in more detail than ever before.'' ''John. Hopkins University Tim. Heckman said; "It's like a living fossil found in your own backyard." We think that this type of galaxy is extinct, but in fact the newborn galaxies survive very well in the universe. ”
The telescope, launched last year, looked at thousands of galaxies and identified a handful of galaxies that are about 10 times brighter than the Milky Way under ultraviolet light. Intense ultraviolet radiation suggests that these galaxies are filled with young stars. These stars appear to be massive, but their lifespan is very short, and then they explode to form a galaxy using heavier elements that use less massive, longer-lived stars to form stars commonly found in mature galaxies.
The findings will be published in a special issue of the Astrophysical Journal Newsletter.
Related knowledge
Galaxies are gravitationally bound systems of stars, stellar remains, interstellar gas, dust, and dark matter. The word Galaxy is derived from the Greek galaxias (γαλαξ α), which literally means "Milky Way" (see Milky Way). Galaxies range in size from dwarf galaxies with only a few hundred million (108) stars to massive galaxies with trillion (1014) stars[4] orbiting their mass centers. The Milky Way is the galaxy in which the solar system, including Earth, is located. Galaxies outside the Milky Way are collectively known as extragalactic galaxies.
Galaxies are classified as elliptical, spiral, or irregular according to their visual patterns.[7] Many galaxies are thought to have supermassive black holes at their centers. The black hole at the center of the Milky Way, known as Sagittarius A*, is 4 million times more massive than the Sun. As of March 2016, GN-z11 is the oldest and most distant galaxy observed, moving 32 billion light-years from Earth, meaning it existed only 400 million years after the Big Bang.
BY: Robert Roy Britt
FY: Haruka
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