This illustration shows a galaxy forming only a few hundred million years after the Big Bang, when the gas was a mixture of transparent and opaque during the reionization era. Data from NASA’s James Webb Space Telescope shows that there is a lot of cold, neutral gas near these early galaxies – and that this gas may be denser than expected.
Webb observed these galaxies as part of his Cosmic Evolution Early Release Science (CEERS) survey a few months after he began making observations in 2022. CEERS includes both images and data known as spectra from the microshutters on board its NIRSpec (near infrared spectrograph). The CEERS data were released immediately to support discoveries like this through Webb’s Early Release Science (ERS) program. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)
Using the
” data-gt-translate-attributes=”({“attribute”:”data-cmtooltip”, “format”:”html”})” tabindex=”0″ role=”link”>James Webb Space TelescopeResearchers from the University of Copenhagen have become the first to observe the formation of three of the universe’s earliest galaxies, more than 13 billion years ago.
For the first time in the history of astronomy, researchers from the Niels Bohr Institute have witnessed the birth of three of the oldest galaxies in the universe, between 13.3 and 13.4 billion years ago. ‘years.
The discovery was made using the James Webb Space Telescope, which brought these first “live observations” of formative galaxies to us here on Earth.
Using the telescope, researchers were able to observe signals from large amounts of gas accumulating and accumulating on a mini-galaxy under construction. Although this is how galaxies form according to theories and computer simulations, it has never actually been observed.
“You could say that these are the first ‘direct’ images of galaxy formation that we have ever seen. While James Webb has already shown us the first galaxies in later stages of evolution, here we are witnessing their birth and thus the construction of the first star systems in the universe,” explains Assistant Professor Kasper Elm Heintz of the Niels Bohr Institute. who led the new study.
The study was published in the prestigious scientific journal Science.
How they did it
Researchers were able to measure the formation of the universe’s first galaxies using sophisticated models showing how light from these galaxies was absorbed by the neutral gas in and around them. This transition is known as the Lyman-alpha transition.
By measuring the light, the researchers were able to distinguish the gas in newly formed galaxies from other gases. These measurements were only possible thanks to the capabilities of the James Webb Space Telescope’s incredibly sensitive infrared spectrograph.
Galaxies born shortly after the Big Bang
Researchers estimate that the birth of the three galaxies occurred approximately 400 to 600 million years after the birth of these three galaxies.
” data-gt-translate-attributes=”({“attribute”:”data-cmtooltip”, “format”:”html”})” tabindex=”0″ role=”link”>Big Bang, the explosion that started it all. Although this seems like a long time, it corresponds to the formation of galaxies during the first three to four percent of the overall lifespan of the universe, or 13.8 billion years.
Shortly after the Big Bang, the universe was a huge opaque gas of hydrogen atoms – unlike today, where the night sky is dotted with a blanket of well-defined stars.
“In the few hundred million years after the Big Bang, the first stars formed, before stars and gas began to merge to form galaxies. This is the process that we see the beginning of in our observations,” explains Associate Professor Darach Watson.
The birth of galaxies took place during a time in the history of the universe known as the epoch of reionization, when the energy and light of some of the first galaxies broke through the mists of hydrogen gas.
It is precisely these large quantities of hydrogen gas that researchers captured using the infrared vision of the James Webb Space Telescope. It is the most distant measurement of cold, neutral hydrogen gas, the building block of stars and galaxies, discovered by scientific researchers to date.
About the first universe
The universe began its “life” approximately 13.8 billion years ago during a huge explosion: the Big Bang. This event gave rise to an abundance of subatomic particles such as quarks and electrons. These particles joined together to form protons and neutrons, which then coalesced into atomic nuclei. About 380,000 years after the Big Bang, electrons began to orbit atomic nuclei and the simplest atoms in the universe gradually formed.
The first stars formed after a few hundred million years. And at the heart of these stars the largest and most complex atoms around us were formed.
Later, stars merged to form galaxies. The oldest galaxies we know of formed approximately 3 to 400 million years after the Big Bang. Our own solar system was born about 4.6 billion years ago, more than 9 billion years after the Big Bang.
Adds to the understanding of our origins
The study was carried out by Kasper Elm Heintz, in close collaboration with, among others, his research colleagues Darach Watson, Gabriel Brammer and doctoral student Simone Vejlgaard from the Cosmic Dawn Center at the Niels Bohr Institute at the University of Copenhagen – a center whose stated goal is to investigate and understand the dawn of the universe. This latest result brings them much closer to this goal.
The research team has already requested more observing time with the James Webb Space Telescope, hoping to delve deeper into their new results and learn more about the earliest epoch of galaxy formation.
“For now, it’s about mapping our new observations of forming galaxies in even more detail than before. At the same time, we are constantly trying to push the limits of our visibility in the universe. So maybe we will go even further,” says Simone Vejlgaard.
According to the researcher, this new knowledge helps answer one of humanity’s most fundamental questions.
“One of the most fundamental questions we humans have always asked is: ‘Where did we come from?’ Here, we piece together a little more of the answer by shedding light on when some of the first structures in the universe were created. This is a process that we will study in more detail, until we can hopefully put even more pieces of the puzzle together,” concludes Associate Professor Gabriel Brammer.
Reference: “Strong damped Lyman-α absorption in young star-forming galaxies at redshifts 9 to 11” by Kasper E. Heintz, Darach Watson, Gabriel Brammer, Simone Vejlgaard, Anne Hutter, Victoria B. Strait, Jorryt Matthee, Pascal A. Oesch, Pall Jakobsson, Nial R. Tanvir, Peter Laursen, Rohan P. Naidu, Charlotte A. Mason, Meghana Killi, Intae Jung, Tiger Yu-Yang Hsiao, Abdurro’uf, Dan Coe, Pablo Arrabal Haro , Steven L. Finkelstein and Sune Toft, May 23, 2024, Science.
DOI: 10.1126/science.adj0343
The study was led by Kasper E. Heintz, Darach Watson, Gabriel Brammer, Simone Vejlgaard, Anne Hutter, Victoria B. Strait, Jorryt Matthee, Pascal A. Oesch, Pall Jakobsson, Nial R. Tanvir, Peter Laursen, Rohan P . , Charlotte A. Mason, Meghana Killi, Intae Jung, Tiger Yu-Yang Hsiao, Abdurro’uf, Dan Coe, Pablo Arrabal Haro, Steven L. Finkelstein and Sune Toft.
The Danish part of the research is funded by the Danish National Research Foundation and the Carlsberg Foundation.