- 4535 - EARLIEST GALAXIES - how could they have formed? James Webb telescope confirms the earliest galaxy in the universe is bursting with way more stars than we thought possible. This light from the most distant galaxy in the known universe suggests that there's something off about our current cosmological models. The explanations remain elusive.
------------------------- 4535
- EARLIEST GALAXIES
- how could they have formed?
-
- The JWST
has spotted the earliest galaxy ever seen, and its unusually bright
light is coming from a bizarre frenzy of star formation. Named JADES-GS-z14-0, the galaxy formed at
least 290 million years after the Big Bang, and contains stars that have been
bursting into life since an estimated 200 million years after our universe
began.
-
- Spotted by JWST's Near InfraRed Spectrograph
(NIRSpec) instrument, the mysterious origins and rapid development of the stars
has opened up some fundamental questions about how our universe came to be.
-
- The discovery by JWST of an abundance of
luminous galaxies in the very early Universe suggests that galaxies developed
rapidly, in apparent tension with many standard models. New galaxy formation models will need to
address the existence of such large and luminous galaxies so earliest in
history.
-
- Astronomers aren't certain when the very
first globules of stars began to clump into the galaxies we see today, but
cosmologists previously estimated that the process began slowly within the
first few hundred million years after the Big Bang.
-
- Current theories suggest that halos of dark
matter which is a mysterious and invisible substance believed to make up 85% of
the total matter in the universe combined with gas to form the first seedlings
of galaxies. One billion to 2 billion years into the universe's life, these
early protogalaxies reached adolescence, forming into dwarf galaxies that began
devouring one another to grow into ones like our own.
-
- But discoveries made by the JWST confounded
this view. In February 2023, a group of astronomers analyzing data from the
telescope discovered a group of six gargantuan galaxies, aged between 500 to
700 million years after the Big Bang, that were so massive they were in tension
with 99% of cosmological models.
-
- James Webb telescope has also found carbon
at the dawn of the universe, challenging our understanding of when life could
have emerged. The light from
JADES-GS-z14-0 is similarly puzzling. In the new research, the light detected
by NIRSpec finds its origins in an enormous halo of young stars surrounding the
galaxy's core, which have been burning for at least 90 million years before the
point of its observation. The galaxy is also crammed with unusually high
quantities of dust and oxygen, which suggests its history of star birth and
death may be even longer.
-
- This finding shows that ultra-bright
galaxies in the early universe are not just the product of active black holes
gobbling up matter, as is often assumed to be the case. The new observations
show that runaway star formation is also a viable explanation for the
surprising brightness of these ancient galaxies.
-
- So how did galaxies like JADES-GS-z14-0
produce so many stars, so quickly? Answers to this cosmic mystery remain
elusive, but it's unlikely they will break our current understanding of
cosmology. Instead, astronomers are toying with explanations that include the
earlier-than-anticipated appearance of giant black holes; supernova feedback;
or even dark energy to understand why these ancient stars were able to form so
rapidly.
-
-
August 12, 2024 4535
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--------------------- --- Wednesday, August 14,
2024
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