The James Webb Telescope has spotted something astronomers previously thought was impossible: a spiral galaxy from the early days of the universe.
This discovery means that galaxies may not always need billions of years to develop the complicated structures seen in spiral galaxies like our own Milky Way.
“This galaxy, named ceers-2112, formed soon after the Big Bang,” Alexander de la Vega, a postdoctoral researcher at the University of California and co-author of the research, said in a press release. “Finding ceers-2112 shows that galaxies in the early universe could be as ordered as the Milky Way. This is surprising because galaxies were much more chaotic in the early universe and very few had similar structures to the Milky Way.”
The research, published in the peer-reviewed journal Nature this week, describes how this newly discovered galaxy opens up new avenues and questions in the field of galaxy development.
The centre of ceers-2112 is defined by a bar, which is a cluster of stars stretching across it. These layered structures are mostly found in spiral galaxies, and are thought to be possible only when stars are rotating in a more predictable pattern.
“The bar in ceers-2112 suggests that galaxies matured and became ordered much faster than we previously thought, which means some aspects of our theories of galaxy formation and evolution need revision,” de la Vega said.
The universe is believed to be around 13.8 billion years old, and astronomers previously thought that complex galaxy structures needed at least around seven billion years to form. The early universe was believed to be defined by more chaotic galactic structures that were too young to have a clear structure.
“The discovery of ceers-2112 shows that it can happen in only a fraction of that time, in about one billion years or less,” de la Vega said.
The discovery was made possible through use of the James Webb Telescope, which is the most powerful telescope to ever set its sights on the skies.
“Initially, I thought detecting and estimating properties of bars in galaxies like ceers-2112 would be fraught with measurement uncertainties,” de la Vega said. “But the power of the James Webb Space Telescope and the expertise of our research team helped us place strong constraints on the size and shape of the bar.”
This discovery doesn’t just change how we think about galaxy formation—it also has implications for how dark matter might work, according to researchers. Dark matter is an invisible substance theorized to compose the majority of the seemingly empty space of the universe. Its existence helps to make sense of how gravity and the objects in space function together, and so it plays a key part in many theoretical models of galaxy formation.
“These models may need to adjust how much dark matter makes up galaxies in the early universe, as dark matter is believed to affect the rate at which bars form,” de la Vega said.
Researchers are hopeful that this could pave the way for more distant complex galaxies to be discovered.