Cosmologic philosophy: latest Webb telescope reports: (Introduction)

by David Turell , Thursday, September 15, 2022, 00:56 (590 days ago) @ David Turell

Earliest galaxies too huge for current theory:

https://www.scientificamerican.com/article/jwsts-first-glimpses-of-early-galaxies-could...

"A redshift of 11 corresponds to a cosmic age of about 400 million years, a point at the brink of when galaxy formation was thought to begin. But from the very first GLASS data, two teams—one led by Naidu in that breathless late-night discovery—independently found a candidate for a more distant galaxy, dubbed GLASS-z13, at a redshift of 13—some 70 million years farther back in time. In their thirst for quick results, the researchers relied on redshift estimates derived from simple brightness-based measurements. These are easier to obtain, but less precise than direct measurements of redshift, which require more dedicated observation time. Nonetheless, the simplified technique can be accurate, and here it suggested a galaxy that was unexpectedly bright and big, already bearing a mass of stars of a billion suns, just a few hundred times less than that of the Milky Way, despite our own galaxy being billions of years more mature. “This was beyond our most optimistic expectations,” says Tommaso Treu, an astronomer at the University of California, Los Angeles, and the lead on GLASS.

"The record did not last long. In the following days, dozens of galaxy candidates from CEERS and GLASS sprung into view with estimated redshifts as high as 20—just 180 million years after the big bang—some with disklike structures that were not expected to manifest so early in cosmic history. Another team, meanwhile, found evidence for galaxies the size of our Milky Way at a redshift of 10, less than 500 million years after the big bang. Such behemoths emerging so rapidly defies expectations set by cosmologists’ standard model of the universe’s evolution. Called Lambda CDM (LCDM), this model incorporates scientists’ best estimates for the properties of dark energy and dark matter, which collectively act to dominate the emergence of large-scale cosmic structures. (“Lambda” refers to dark energy and “CDM” refers to dark matter that is relatively sluggish, or “cold.”) “Even if you took everything that was available to form stars and snapped your fingers instantaneously, you still wouldn’t be able to get that big that early,” says Michael Boylan-Kolchin, a cosmologist at the University of Texas at Austin. “It would be a real revolution.” (my bold)

***

"JWST’s discovery of bright galaxies in the early cosmos challenges this model. “We should see lots of these little protogalactic fragments that have not yet merged to make a big galaxy,” says Stacy McGaugh, a cosmologist at Case Western Reserve University in Ohio. “Instead, we’re seeing a few things that are already big galaxies.”

***

"David Spergel, a renowned theoretical astrophysicist and current president of the Simons Foundation in New York, agrees. “I think what we’re seeing is that high-mass star formation is very efficient in the early universe,” he says. “The gas pressures are higher. The temperatures are higher. That has an enormous impact on the environment for star formation.” Perhaps even magnetic fields arose earlier in the universe than we thought, playing a crucial role in driving material to kick-start the birth of stars. “We might be seeing a signature of magnetic fields emerging very early in the universe’s history,” Spergel says."

Comment: efficient very early large galaxy formation smells of a designer at work. The story of how the universe evolved is still unfolding.