The six candidate galaxies identified in the JWST data. / NASA, ESA, CSA, I. Labbe/Swinburne University of Technology
The Sextet
The finding came from observations made by the James Webb Space Telescope (JWST) during its first few months of operation. The data has astronomers perplexed, as they are massive galaxies and well formed.
All of this raises questions about what is known about the evolution of the universe. One of the main goals of the JWST is to look further into space-time than any previous instrument.
The sextet is more than 12 billion years old and reaches sizes up to 100 billion times the mass of our sun. “We have never observed galaxies of this colossal size, so early after the Big Bang,” says astronomer Ivo Labbé of Swinburne University of Technology.
The sextet is more than 12 billion years old and reaches sizes up to 100 billion times the mass of our sun. “We have never observed galaxies of this colossal size, so early after the Big Bang,” says astronomer Ivo Labbé of Swinburne University of Technology.
Labbé claims that the discovery of the six massive galaxies is an important milestone in the field of astronomy. Furthermore, solving the mystery could change our understanding of how galaxies formed in the early universe.
Issues
Science tells us that after the Big Bang, the hot soup of particles that emerged had to cool enough to freeze into atoms, filling the volume of space mostly with hydrogen and helium. It is from this gas that the first stars and galaxies began to form, around 150 million years after the Big Bang.
However, according to current cosmological models, the galaxies would still have been coming together in the period between about 500 and 700 million years after the Big Bang. So the incredible find poses a problem.
First, the density of matter within today’s largest galaxies far exceeds estimates for this time period. Second, the density of normal matter is in tension with the amount of dark matter in the halos of these galaxies.
Everything points to one of two things being wrong. Our understanding of cosmology or our understanding of galaxy formation in the early universe. Either way, the result means that we are touching the edges of knowledge.
First, the density of matter within today’s largest galaxies far exceeds estimates for this time period. Second, the density of normal matter is in tension with the amount of dark matter in the halos of these galaxies.
Everything points to one of two things being wrong. Our understanding of cosmology or our understanding of galaxy formation in the early universe. Either way, the result means that we are touching the edges of knowledge.
Explanation
The objects may not actually be galaxies. They could be supermassive black holes of a kind never seen before. Even so, the amount of mass concentrated in one place remains difficult to explain so early in the universe. That could also lead us to review our knowledge about black holes. see
Any such object would be difficult enough to explain. Further investigation will help us define what we are looking at. The next step will be to try to obtain spectra of the candidate galaxies, thus revealing their natures, distances and sizes in more detail.