Scientists have spotted an
oxygen signal deep in the universe, suggesting it formed far differently from
how we thought. The new discovery is the most distant oxygen ever seen by a
telescope. And it could change our understanding of how stars and the universe
as we know it came about.
The galaxy is so far away
that we are seeing it as it was when the universe was only 500 million years
away. And even at that age, it is filled with mature stars – suggesting the
process of their formation began only 250 million years after the universe
itself began.
For some time after the big
bang, there was no oxygen in the universe. It did not come about until after
the first stars were formed, being released when they died again.
As such, the oxygen discover
was unexpected because it suggests that had happened even when the universe was
relatively young. That discovery appears to be confirmed by a model that
confirms the current brightness of the universe corresponds with it being
formed when it was only 250 million years old.
Scientists described the
detection of such distant oxygen as a discovery that fundamentally changes our
understanding of the beginnings of the universe, as well as being a major
breakthrough in our technical exploration of it.
"Rather than saying I
was happy, it would be more accurate to say I was thrilled to see the signal of
the most distant oxygen," explains Takuya Hashimoto, the lead author of
the research paper published in the journal Nature and a researcher at Osaka
Sangyo University and the National Astronomical Observatory of Japan. "I
was excited enough that the signal appeared in my dreams and I had difficulty
sleeping that night."
The age of those stars
raises questions about when the very first galaxies emerged from the complete
darkness that initially made up the universe, a moment known by scientists as
the Cosmic Dawn.
"Determining when
cosmic dawn occurred is akin to the Holy Grail of cosmology and galaxy
formation," said Richard Ellis, senior astronomer at UCL and co-author of
the paper. "With these new observations of MACS1149-JD1 we are getting
closer to directly witnessing the birth of starlight! Since we are all made of
processed stellar material, this is really finding our own origins."
It also suggests that
galaxies were forming long before we can actually see them now, making the
process of star formation even more mysterious.
"The mature stellar
population in MACS1149-JD1 implies that stars were forming back to even earlier
times, beyond what we can currently see with our telescopes. This has very
exciting implications for finding 'cosmic dawn' when the first galaxies
emerged," adds Nicolas Laporte, a researcher at University College
London/Université de Toulouse and a member of the research team.
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