Noon of Creation

NASA/JWST/Backhaus

About 380,000 years after the Big Bang, the first atoms formed. The first light of what we now see as the cosmic microwave background was released, and the primordial hydrogen and helium grew cold and dark. The cosmos entered a dark age for about 100 million years until the first stars and galaxies started to form. You could say the rise of galaxies marked cosmic morning. But star formation didn’t really kick into gear for another 2-3 billion years, during what astronomers call cosmic noon. This period can be difficult to observe, but a new study gives us an unprecedented view of this epoch.¹

The study is based on data gathered by the MIRI EGS Galaxy and AGN (MEGA), which used the James Webb Space Telescope (JWST) to capture large areas of the sky at mid-Infrared wavelengths. This is a wavelength region where dust emits so the survey can see the dusty regions of galaxies where star formation occurs.

The team found that star production during cosmic noon was even greater than we had thought. About half the stellar mass of galaxies across the Universe were formed during this period. The data also shows that galactic black holes experienced rapid growth during this time as well. By the end of the cosmic noon period, the Universe resembled the modern epoch. It was a period of cosmic puberty, where the Universe transformed from its childhood to its mature stage.

This is only an initial study, and much of the data is still being analyzed. In the near future, the team hopes to find young galaxies similar to the Milky Way and better understand how our home galaxy evolved. They also want to study galactic collisions and black hole mergers to see how these help drive star production.