Scientists have discovered a huge spiral galaxy with an ordered structure in the early universe, but cannot explain how it grew so big so quickly.
Using the Webb Space Telescope, astronomers have discovered a spiral galaxy with an ordered structure about 32,000 light-years in diameter. It existed 1.5 billion years after the Big Bang.
But galaxies in the early universe are clumpier and lack an ordered structure. So this discovery has stunned astronomers. The research was published on the preprint server arXiv, Living Science writes.
Astronomers have discovered an unexpectedly large, well-ordered spiral galaxy in the early universe, 32,000 light-years across, called A2744-GDSp-z4. That it existed 1.5 billion years after the Big Bang could change what astronomers know about the formation of galaxies, and spiral galaxies in particular.
In general, the older a galaxy is, the further away it is from Earth. Astronomers can estimate the age of a galaxy and how far away it is by using redshift. When light travels through large areas of space, it shifts toward the red end of the electromagnetic spectrum.
As the universe expands, older stars appear further away. The red part of the spectrum shows the longest wavelength of light, so stars that are very far away appear redder because they are at a redshift. The Webb Space Telescope can see the farthest stars and galaxies in space, which are the oldest.
But astronomers have usually found spiral galaxies closer to us, meaning they are generally younger than the recently discovered galaxy A2744-GDSp-z4. Well-ordered spiral galaxies like this one have two separate spiral arms. Astronomers have previously found very few galaxies with a redshift higher than 3.0, meaning that light from these galaxies has taken about 11.5 billion years to reach us.
But the galaxy A2744-GDSp-z4 has a redshift of 4.03, meaning its light has been traveling to us for more than 12 billion years. According to scientists, calculations show that this galaxy was formed about 1.5 billion years after the Big Bang, or 12.3 billion years ago. At the same time, scientists say the galaxy has grown so big too quickly, although it is still three times smaller than the Milky Way. But for galaxies in the early universe this is a very large size.
A study of the rate at which new stars are formed in the galaxy A2744-GDSp-z4 has shown that the galaxy has gained a mass equivalent to 10 billion solar masses in just a few hundred million years, contradicting the model for the formation of spiral galaxies. galaxies.
Scientists say that spiral galaxies in the early universe were largely clumpy and turbulent. But a spiral galaxy with an orderly structure has been discovered.
Astronomers believe that the galaxy’s rapid growth and orderly structure may be due to the presence of a stellar bar. This is a gaseous structure found in most galaxies that fuels the birth of stars and acts as a conduit for the movement of gas between the inner and outer regions of the galaxy. This movement of gas helps the galaxy grow and shape itself.
The ancient spiral galaxy may have formed from the merger of two smaller galaxies, although this seems less likely given its orderly structure, astronomers say.
