One week after the discovery of the first images of the James Webb Space Telescope, the most powerful ever designed, it could have already found the most distant galaxy ever observed, which existed 13.5 billion years ago.
Named GLASS-z13, it looks to us like it was only about 300 million years after the big bang, 100 million years younger than the previously observed record, said Rohan Naidu of the Smithson Center for Astrophysics at Harvard.
He is the lead author of a study analyzing data from James-Webb’s early observations, which is currently underway. This data is posted online for all astronomers on the planet.
Paper day! “Two remarkably luminous Galaxy candidates at z ~ 11-13 unveiled by Just Wonderful Space Telescope”. T https://t.co/BmU5AGvYYF
One of the main tasks of this brand new telescope is to observe the first galaxies formed after the big bang, which took place 13.8 billion years ago. In astronomy, looking far is like going back in time. Light from the Sun, for example, takes eight minutes to reach us, and then we see it as it was eight minutes ago. By looking as far as possible, we can thus see objects as they were billions of years ago. The light from this galaxy was emitted 13.5 billion years ago.
A red circular shape
This study has not yet been peer reviewed, but published as pre-print, to be quickly accessible to the expert community. It has been submitted to a scientific journal for forthcoming publication, Rohan Naidu said. But already many astronomers enthusiastically commented on this discovery on social networks.
“The records in astronomy are already faltering”, tweeted Thomas Zurbuchen, NASA Associate Director of Science. “Yes, I tend to applaud only peer-reviewed scientific results. But it’s very promising!”, he added about the study. Another research team concluded with the same results, according to Rohan Naidu, who “give confidence”.
The galaxy was observed by James-Webb’s NIRCam instrument and detected on what is called a “deep field”i.e. a wider image taken with a long exposure time to detect the faintest glows.
The special thing about James-Webb is only to operate in the infrared. The light emitted by the oldest objects has stretched and “blush” along the way, passes through this wavelength which is not visible to the human eye. Therefore, to draw a picture of this galaxy, the data became “translated” in the visible spectrum: it then appears as a red circular shape, rather blurred and white in the middle.
“There is still work”
In fact, the approximately twenty scientists who participated in the study studied two galaxies, the other being called GLASS-z11, which is less distant. They have surprising properties, for the little we already know: “They look pretty massive”according to Rohan Naidu, from “very soon after the big bang.” “It’s something we do not really understand”he added.
When exactly did they occur? Impossible to say at the moment. “There is still work”, said the researcher. He and his colleagues asked for more observation time with the telescope to perform spectroscopic analyzes – a technique for determining the properties of a distant object by analyzing the collected light. This should confirm their distance.
The James Webb Telescope was launched into space about six months ago. To the value of $ 10 billion, it was located 1.5 million kilometers from us. It has enough fuel to run for twenty years.