Galaxies in the early universe were like chaotic toddlers, struggling to settle down. A new study using the James Webb Space Telescope (JWST) looked at over 250 galaxies from 800 million to 1.5 billion years after the Big Bang, revealing how messy they really were.
The research, published on October 21 in the Monthly Notices of the Royal Astronomical Society, shows that these young galaxies were much more restless than scientists thought. Lead author Lola Danhaive from Cambridge noted that many galaxies were in a turbulent phase, not smooth and stable like our Milky Way.
Previous studies focused primarily on bigger, more regular galaxies, missing these smaller, chaotic ones. By studying less massive galaxies, Danhaive’s team uncovered what they call “messy kinematics.” The turbulence during this phase was higher than expected, driven by large amounts of gas fueling intense star formation.
This turbulence in the galaxy disk likely occurs because of gravitational instabilities caused by all that gas. At this stage, galaxies transition from chaotic to more structured formations. Danhaive explained that as galaxies mature, they become more stable as their gas gets used up for star creation.
Interestingly, this research illuminates how galaxies evolve over billions of years. Structures like the Milky Way formed more recently and are now more organized. With less gas available, mature galaxies can grow and change without the same level of disruption.
The JWST is crucial for these breakthroughs. It operates far from Earth’s light pollution and can see deeper into space than previous telescopes. This allows scientists to discover some of the earliest galaxies known. Danhaive said the JWST and simulations are key in understanding how star formation impacts galaxy evolution.
In the next steps, the research team plans to investigate how gas flows in and out of galaxies and its chemical enrichment. They expect incoming gas to be “pristine,” while outflowing gas will show changes due to interactions with stars. Understanding these dynamics can help explain why some galaxies rotate faster than others.
In summary, this study opens up a new perspective on early galaxies, challenging previous beliefs and laying the groundwork for future research. With the JWST’s capabilities, the mysteries of early galaxy formation are just beginning to be unraveled.
