James Webb Telescope Discovers a Mysterious Group of Galaxies?

Astrophysicists explain how the James Webb Telescope discovered a mysterious group of galaxies that threatens to disrupt cosmology.

The galaxies discovered by the James Webb Space Telescope (JWST) formed as early as 500 million years after the Big Bang, and are so bright that they theoretically should not have existed. The Milky Way, these early galaxies, formed in a very short time compared to our own.

The discovery threatens to overturn physicists' understanding of galaxy formation and even the standard model of cosmology.

Picture 1 of James Webb Telescope Discovers a Mysterious Group of Galaxies?
This illustration shows a chaotic, disorderly galaxy undergoing bursts of star formation. (Image: ESA, NASA, L. Calçada)

Using supercomputer simulation

Now, a team of researchers using supercomputer simulations suggests the galaxies might not be that big – they might be unusually bright.

'Normally, a galaxy is bright because it is big. How could these massive galaxies have come together so quickly? Our simulations show that galaxies had no trouble forming this brightness at the cosmic dawn ,' said senior study author Claude-André Faucher-Giguère, an astrophysicist at Northwestern University.

Currently accepted theories suggest that these first protogalaxies reached adolescence 1 to 2 billion years into the life of the universe - forming into dwarf galaxies that began devouring each other to grow into galaxies like our own.

That's what made JWST's discovery of thousands of unusually bright early galaxies, some even resembling our own, a surprise to astronomers. It's a discovery that throws their most basic understanding of how the universe evolved into serious doubt.

To investigate what might have given these galaxies their strange sparkle, the researchers created a model of galaxy formation and ran it through a supercomputer – simulating the swirling, condensing gas of the early universe as it turned into stars, which in turn formed galaxies.

By carefully calculating the mass, energy, momentum, and chemical composition of the young universe, the researchers found that stars at this early time may have formed in sudden , rapid explosions after years of silence. Known as 'explosive star formation ,' this process is unlike the steady rate of star formation in the universe today and may explain why the early universe was so bright.