Six giant galaxies that astronomers thought didn’t exist yet: Astronomers were surprised by the discovery of the James Webb Telescope. Astronomer Leen Decin (KU Leuven), who is also conducting research with this telescope, notes that “95 percent of our models have never predicted anything like this.”
What exactly did your colleagues discover?
“First step back. We’re trying to find an answer to the question of how the oldest stars were born. We do this to get an idea of how our Milky Way came to be. So we look at very old galaxies, which is a very good thing in the James Webb telescope. All celestial bodies emit light. Our universe “It’s constantly expanding a little bit. As a result, the light that everything is emitting gets redder—we call that redshift. Webb’s is very sensitive to that infrared light.”
“Using Webb, we’ve now been able to look at light from hundreds of millions of years after the Big Bang. To the average person, 100 million years seems like a very long time. To a split-second astronomer, if you know our universe is 13.8 billion years old.” years. What turns out now? Stars in galaxies that were much larger than we expected.”
What do you mean by “massive” galaxies?
Its mass exceeds 10 to 100 billion solar masses. Most models have assumed that these first stars will be in much brighter galaxies.”
“We thought that small galaxies could become very heavy just by colliding and merging. The more collisions, the bigger the galaxy: that was the reason. This also seemed to us to be a logical genesis for our Milky Way. Now we look on the web and see that we were wrong.”
What does it mean?
Our models are wrong! (He laughs) We make models based on all the observations we can make. We don’t call the James Webb Telescope the Universe Telescope for nothing: it allows us to make observations that were previously impossible. Now that we’ve tested it against our models, it appears to be incorrect: the first supermassive galaxies. I think 95% of our models never expected this. So it turns our thinking upside down.”
So what did the old models expect?
These gases should have taken longer to cool down and turn into stars and galaxies after the Big Bang. This finding shows that the time period is likely to be much shorter.”
What now?
“We need to collect new observations and revise our models. We now have six new anchor points: that’s not much. We can look closer to the Big Bang using the web. But that takes a lot of time, because the light emitted at that time is much weaker.”
In addition, we have to ask ourselves what physical or chemical elements we need to adjust in our models in order to show that we can reach massive galaxies so quickly. These are complex calculations. We may have made a simplification somewhere that has now turned out to be wrong. This is science. ”
Why does the average person lose sleep because of this discovery or not?
“I get this question a lot. My answer is always the same, and it’s actually philosophical. Man wants more than bread and circuses: many people are really interested in the question of where we come from, what is our place within this universe and how we live on a viable planet. Nobody can answer to these questions.
However, this discovery again provides a small part of the answer to the question of what our home is, our home. Suddenly it seems that there is a whole cellar under the house, so to speak, when we thought it was just solid foundations. It is now up to us to understand how this vault was excavated and what its function is.
