(ORDO NEWS) — According to the James Webb Space Telescope observations, the first galaxies could have formed much earlier than previously thought, according to the James Webb Space Telescope observations, which are changing astronomers’ understanding of the early universe.
Researchers using a powerful observatory have published the results. articles in the Astrophysical Journal Letters describing two exceptionally bright and exceptionally distant galaxies based on data collected during the first few days of Webb’s start in July.
First, these galaxies are very massive, with lots of low-mass stars like today’s galaxies, and should have started forming 100 million years after the Big Bang, which happened 13.8 billion years ago.
This is 100 million years earlier than the current end of the so-called cosmic dark age, when the universe contained only gas and dark matter.
The second possibility is that they are composed of “Population III” stars, which have never been observed, but are assumed to have consisted only of helium and hydrogen before the heavier elements appeared.
Because these stars burned so brightly at extreme temperatures, the galaxies made up of them didn’t have to be that massive to account for the brightness observed by Webb, and could start forming later.
“We see such bright, such glowing galaxies at this early time. that we’re really not sure what’s going on here,” Garth Illingworth of UC Santa Cruz told reporters.
The rapid discovery of galaxies also fell short of Webb’s expectation that a larger volume of space is required to find such galaxies.
“Somewhat surprising that so much formed so early,” added astrophysicist Ceyhan Kartaltepe of the Rochester Institute of Technology.
The most distant starlight
Two galaxies are found to definitely have exi about 450 and 350 million years after the Big Bang.
The second of these, called GLASS-z12, now represents the most distant starlight ever observed.
The more distant objects are from us, the longer it takes for their light to reach us, and therefore to look at a distant universe is to look into the deep past.
Because these galaxies are so far from Earth, by the time their light reaches us, it has been stretched out due to the expansion of the universe and shifted to the infrared region of the light spectrum.
Webb can detect infrared light at a much higher resolution than any instrument before him.
Illingworth, who co-authored the paper on GLASS-z12, told AFP that unraveling the two competing hypotheses would be “a real challenge,” though the idea of population III was more appealing to him because it didn’t require turning it on its head. existing cosmological models.
The teams hope to soon use Webb’s powerful spectrographic instruments, which analyze light from objects down to r to reveal their detailed properties to confirm distances to galaxies and better understand their composition.
The Atacama Large Millimeter/Submillimeter Array (ALMA), a ground-based telescope in northern Chile, can also help. weighing the masses of the two galaxies, which would help to choose between the two hypotheses.
“JWST has opened up a new frontier, bringing us closer to understanding how it all began,” summarized Tommaso Treu of the University of California at Los Angeles, principal investigator of one of Webb’s programs.
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