Far out cosmology: earliest galaxies go bananas (Introduction)

by David Turell , Tuesday, January 09, 2024, 16:50 (317 days ago) @ David Turell

That is the general shape seen:

The Early Universe Was Bananashttps://www.spacequarter.com/galaxies-in-the-early-universe-were-shaped-like-ban...

"Rather than eggs or discs, baby galaxies appear to have peculiar shapes, such as bananas, pickles, cigars, or surfboards – take your pick of metaphors. A team of astronomers re-examined images of approximately 4,000 newborn galaxies observed by the Webb telescope during the early stages of the universe, leading them to this surprising conclusion.

***

"If this result holds true, it could have significant implications for our understanding of how galaxies form and evolve. Additionally, it may offer insights into the mysterious nature of dark matter, an invisible form of matter that is believed to make up a substantial portion of the universe, outweighing atomic matter by a ratio of 5 to 1. Dark matter envelops galaxies and provides the gravitational nurseries where new galaxies emerge.

"The discovery builds on earlier observations from the Hubble telescope, which suggested that the earliest galaxies had pickle-like shapes, according to Joel Primack, an astronomer at the University of California, Santa Cruz, and a co-author of the new paper.

"While the result is considered important, some scientists maintain a level of skepticism due to the difficulty of making such measurements, particularly for galaxies that are far away, small, and not very bright.

***

"Galaxies are like the city-states of the cosmos, with an estimated two trillion existing within the visible universe. Each galaxy can contain as many as a trillion stars. However, the visible universe represents only a fraction of what lies beyond. Most of the matter in the cosmos is believed to be dark matter, which constitutes the invisible framework of the universe we observe.

"According to current theories, galaxies were formed from random fluctuations in the density of matter and energy during the Big Bang. As space expanded, denser areas lagged behind, causing dark matter to accumulate and pull normal matter with it. Eventually, this material came together and started emitting light as stars and galaxies or collapsed into black holes. The Webb telescope was designed to investigate this formative and enigmatic era, allowing scientists to observe the most distant and earliest galaxies with its giant mirror and infrared sensors.

***

"However, astronomers have observed a different pattern. Instead of round shapes, they have observed many elongated shapes resembling cigars or bananas. These oblong galaxies are rare in the present universe but make up a significant portion of the galaxies in the CEERS sample, which reaches back approximately 500 million years after the Big Bang. These galaxies have masses similar to those of galaxies like the Milky Way, suggesting that our own galaxy may have undergone a similar cigar/surfboard-shaped phase in its past.

"In the modern universe, galaxies typically fall into two categories: featureless, roundish clouds known as ellipticals, and flat, disc-like structures like our Milky Way. However, it seems that the earliest galaxies did not start out this way. The peculiar shapes observed in these baby galaxies are suspected to be related to the properties of dark matter, although the specifics remain unclear."

Comment: the more we learn about the universe the more we need to learn. I did not include a discussion of dark matter effects theories.