how to measure the size of the universe
Usually when searching for old galaxies with near-infrared instruments, we observe what appears to be a sharp spectral break at the Lyman critical alpha wavelength (0.1216 micrometers; ultraviolet range), known as the “Lyman break”.
The reason for this is that the age of galaxies and the size of the universe can be measured by examining to what extent the spectrum has shifted to longer wavelengths, that is, how much the Lyman critical alpha wavelength has caused a redshift, and obtaining accurate redshift values. Through this, the James Webb Space Telescope team has discovered an old galaxy with a redshift (z) value of 13.20, which was formed less than 400 million years after the Big Bang.
(Link to related article – “James Webb Observes Older, More Distant Galaxies”)
Similarly, the “Balmer cut”, which uses the critical Balmer wavelength (about 364.5 nanometers), is often used to study the masses, ages and cosmic history of galaxies.
A research team found 6 candidate galaxies between 500 and 700 million years old
NASA’s James Webb uses specialized infrared light to see the past and dark space.
Therefore, we observe galaxies that formed only a few hundred million years after the Big Bang, which is only a fraction of the current age of the universe.
An international astronomy research team led by Professor Ivo Labbé at Swinburne University of Technology in Melbourne, Australia, used the James Webb Space Telescope to find galaxies with a redshift of 6 or more that are only about a billion years after the Big Bang. observations.
“Big, massive galaxies that shouldn’t exist” have been discovered. These are 6 galaxies above the gray line (threshold). © Labbé et al. 2023
As a result of observation, the research team found six candidates for galaxies between 500 and 700 million years old with redshift values ranging from 7.4 to 9.1. These galaxies have about 10 to 100 billion times the mass of our Sun.
For reference, it is not easy to find massive galaxies that formed earlier because the Balmer Break region required for an accurate mass estimate is shifted to wavelengths greater than 2.5 micrometers.
Discovery of “massive galaxies that shouldn’t exist”
The problem is that the galaxies found this time are massive galaxies that “shouldn’t exist”.
Concerned that the discovery could destroy what we know about the universe, the research team dubbed it the “Universe Breaker,” and if any of these galaxies turns out to be a galaxy ok, cosmology at its limit has warned that they would run into it
The researchers argue that galaxies should not have had this great right after the universe began, based on current theories. The stars are about 100 times more massive than expected.
Pennsylvania State University astronomer Professor Joel Leja, who modeled the observations, argues that the above objects are much more massive than expected, and that the team will only find baby galaxies for the first time. small, young they will observe. expecting it.
In addition, he added that it is very surprising that a galaxy as mature as ours has been discovered through observations of the early universe, known as “the dawn of the universe.”
“Giant galaxies that shouldn’t exist” have been discovered. It shows six galactic observations. © Labbé et al. 2023
Additional spectroscopy studies are scheduled for the above study, so if the above observation is confirmed as fact by further research, it may be scientific evidence that the above galaxies grew much faster than we thought.
It also suggests that we misunderstand the history of the early universe and that cosmic and galaxy models need to be revised.
Professor Reza also explained that he never expected what would be discovered when exploring the early universe for the first time, and that unexpected discoveries surprise the scientific community.
Possibly a black hole or quasar
However, astronomers claim that some can be identified as supermassive black holes, none of which can be 100% certain of their distance or age.
“Giant galaxies that shouldn’t exist” have been discovered. The featured image shows the spectral energy distribution of six galaxies. © Labbé et al. 2023
Professor Erica Nelson of the University of Colorado Boulder from the research team also predicted that if the object above is not a galaxy, it could be a faint quasar or similar type of object, explaining that any situation is actually surprising big
Further observations and studies are definitely needed.
As explained above, this discovery requires further study of the spectrum of the galaxy.
This allows the age and distance of the galaxy to be accurately determined (eg using Lyman’s brakes), which also provides detailed information about the galaxy’s composition and stars.
Further observations and studies are definitely needed. © Labbé et al. 2023/JWST/NASA
This confirms the theory that galaxies can grow faster than expected. That is why additional spectroscopic studies are absolutely necessary.
Go to the related paper – “A population of red massive candidate galaxies ~600 Myr after the Big Bang”
※ Please understand that the phrase “QUICK PREVIEW ARTICLE” was written in the paper because Nature published an unedited version of the paper to reveal the research results early.
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