Two very old galaxies from 300 to 400 million years after the Bigbang have been found by researchers. Astronomers are questioning what they know about how the universe formed after it was young.
The universe has formed faster and earlier than we thought, according to the principal investigator for a program.
It's believed that the most distant galaxy is 350 million years old. The GLASS-JWST Early Release Science Program (Grism Lens-Amplified Survey from Space) and the Cosmic Evolution Early Release Science Survey (CEERS) helped identify the galaxies. Due to the expansion of the universe, the light coming from some galaxies is shifted to the red end of the spectrum. The older the universe is due to the further the light has traveled before reaching us.
The further the light has traveled, the sooner it will reach us.
Researchers begin to identify the oldest galaxies by looking at images taken by the JWST and selecting the ones they like the most. They look for galaxies that don't show up in the visible light wavelength, but do show up in the IR range. It's possible that a very early galaxy is redshifted so much that it's no longer visible to the naked eye.
There are other reasons that a galaxy might not be seen. Dust can cause optical light to be blocked. We need more data in order to confirm that a galaxy is very old.
When we see emission lines from different elements, it shows us exactly what we are looking at. We need to go towards that gold standard.
The most distant galaxy has been confirmed with data from ALMA. There have been lots of preliminary announcements of even earlier galaxies, and we're still trying We feel good about these two, but not so good about the others.
Researchers have differing opinions about the accuracy of early data from the JWST. The number of galaxies that had redshifts as high as 13 has been refined down to 12.5 with more accurate calibrations. The earliest data was from when the telescope was in space and the more recent data was from when the telescope was out of space. As time goes on, the readings will get more accurate.
Gathering data on these targets will give a more in-depth look at the contents of early galaxies. The fingerprints of the different atomic elements that have different colors in the spectrum of the galaxy can be seen. We get more detailed information about the motions of the gas and the rates of star formation.
Astronomers are rethinking their assumptions about the earliest stars because of the bright early galaxies. It is possible that the early bright galaxies are just full of Population III stars and aren't that big. The idea is that Population III stars have different compositions than the stars we see today. Illingworth said, "This is opening up a whole question about the nature of stars and how they form."
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