Far out cosmology: finding first stars (Introduction)

by David Turell @, Monday, January 30, 2023, 21:18 (661 days ago) @ David Turell

Another view:

https://www.nationalgeographic.com/magazine/article/nasa-jwst-most-ancient-galaxies-in-...

“'JWST has absolutely changed our definition of high-z,” writes Guido Roberts-Borsani of the University of California, Los Angeles, in an email. In 2015, he says, the most distant galaxies known had redshift values of 8 or 9. But then the Hubble Space Telescope spotted a galaxy later named GN-z11 around redshift 11 and pushed the first galaxies even further back in time.

“'Now JWST has eclipsed that,” Roberts-Borsani says, and the redshift frontier has been moved to values of 12 or 13, equating to about 13.3 or 13.4 billion years ago.

***

“'We’ve shifted into a completely new regime—this is the first time we’ve got confirmation of anything further away than Hubble could see, and this is just the beginning,” Curtis-Lake, a member of the JWST Advanced Deep Extragalactic Survey (JADES) collaboration, told National Geographic.

***

"Curtis-Lake, Robertson, and their colleagues confirmed the distances to four galaxies that populated the primordial cosmos when it was only about 300 or 400 million years old. Two of them, though they are wicked far away, had also been spied by Hubble. The other two are farther away than anything Hubble could see, with redshifts of 12.6 and 13.2. These galaxies are largely made of lighter elements such as hydrogen and helium because they existed before large amounts of heavier elements had time to form.

“'They’re sort of like little baby toddlers in a universe that hasn’t really got going yet,” Curtis-Lake says.

***

"At first glance, it appears as though the early universe was more prodigious at cooking up stars and galaxies than scientists anticipated.

“'The galaxies we’re finding at those redshifts are more numerous than we expected based on previous observations, and they are also brighter than we expected at those redshifts,” Roberts-Borsani writes. “To fit this ‘new’ picture, galaxies had to start forming earlier and faster than previously thought.”

"Roberts-Borsani is a member of the GLASS-JWST collaboration, which is also searching for high-redshift galaxies and studying them to understand cosmic evolution. The GLASS collaboration studied a patch of sky that lies behind a massive cluster of galaxies, and the team has already uncovered a handful of apparently primordial galaxies—more than simulations had predicted. “Something’s a little bit weird over there,” Roberts-Borsani told astronomers in Baltimore.

"But, he says, there are ways to explain the apparent overabundance without breaking the currently established laws of the universe. Telescopes like JWST can only image small areas of the sky at one time, so by chance, teams could be studying portions of the sky that are unusually stuffed with galaxies. Another possibility is that these early galaxies are simply brighter than expected, perhaps because star formation worked differently than thought. A third explanation is that estimates based on Hubble observations are incomplete because of Hubble’s limited observing capabilities, and maybe, for still unexplained reasons, the early universe was more efficient at turning the lights on than anticipated."

Comment: time will answer the current issues. What appears to be true is the initial conditions baked into the origin of the universe dictated lots of galaxies. Looks like design to me.


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