⇧ [VIDÉO] You might also like this affiliate content (after advertising)
The James Webb Space Telescope offers astronomers images of our universe of unparalleled quality. Scientists pointed it to areas already imaged by Hubble, but the details revealed by Webb are incredibly precise. Recently, this has made it possible to consider the galaxies closest to the big bang (the oldest) known to date. Studying these star clusters could reveal valuable clues about the formation and evolution of the early universe.
NASA’s James Webb Space Telescope was specially designed to detect faint infrared light from very distant galaxies and give astronomers a glimpse into the early universe. The light emitted in the earliest times of our universe must indeed traverse space and time to reach us.
However, as predicted by Einstein’s theory of relativity, the universe is constantly expanding, causing celestial objects to move apart. The light that passes through space is stretched and its wavelengths, which are in the visible spectrum at the beginning, get larger and longer and end up in the near infrared zone, even infrared (for the light of galaxies more distant).
It should be noted that the nature of galaxies during this first light period of the universe is not well known or understood. For scientists, the universe after the big bang was like a hot soup of particles (that is, protons, neutrons and electrons) and without any light.
As the universe began to cool, protons and neutrons began to combine into ionized hydrogen atoms (and eventually helium). These ionized hydrogen and helium atoms attracted electrons and turned them into neutral atoms—allowing light to travel freely for the first time because that light was no longer scattered by free electrons. The universe was no longer opaque!
However, it will take some time (several hundred million years) before the first stars start to form. But astronomers don’t know how. The James Webb Telescope could provide an answer with this new picture of the early universe. It captured an image of a galaxy cluster named MACS0647 as well as the distant galaxy MACS0647-JD.
A galaxy (known for 10 years) that hides another
Dan Coe of AURA/STScI for the European Space Agency and Johns Hopkins University, communicated of NASA explains that he discovered the galaxy MACS0647-JD 10 years ago using the Hubble Space Telescope. It specifies: ” Back then, with HST, it was just this faint red dot. We could say that it was a really small galaxy during the first 400 million years of the universe. We are now looking with Webb and are able to see TWO objects! “.
During a press conference regarding the discovery, a second researcher, Tiger Hsiao of Johns Hopkins University, points out the difference in color between the two objects, one being more blue and the other drawing red. Explains: ” Blue gas and red gas have different properties. The blue actually reveals very young star formation and almost no dust, but the small red object has more dust inside and is older. And their stellar masses are also probably different “.
Without being able to really conclude on the nature of this observation, the two authors agree that it could be a merger of galaxies in the earliest moments of the universe.
Gravitational lens complementing James Webb
The capture of this image was made possible by the presence of a special structure in this zone of space, the gravitational lens. It is a cluster of galaxies located in front of the area the telescope is pointing at. Due to the very strong overall gravity of this cluster, it acts like a magnifying glass on the most distant objects located behind it. The lens not only magnifies these objects, but also multiplies their image in different orientations. Dan Coe explains: Gravitational lensing splits the huge galaxy cluster MACS0647 into three images: JD1, JD2 and JD3. They are amplified by a factor of eight, five and two “.
Studying these images will provide insight into how such galaxies formed and evolved over time into galaxies like the Milky Way, says team member Rebecca Larson of the University of Texas at Austin.
For the trio of researchers, as for all NASA astronomers, James Webb’s prowess is astounding, especially since these discoveries are only related to the telescope’s first image. Rebecca Larson says: If you look at the background, there are all these little dots – and they’re all galaxies! Everyone of them. It’s amazing how much information we’re getting that we couldn’t see before. And it’s not a deep field. It’s not a long exposure. For a long time we didn’t even really try to use this telescope to observe the site. This is just the beginning! “.
Finally, as mentioned CNNthe research team designed a article about the discovery of a potential collapse, but as with most of Webb’s early observations since science operations began in July, the findings have not yet gone through the peer review process. The team also plans a more detailed study of MACS0647-JD in January.