This infrared image from NASA’s James Webb Space Telescope (also called Webb or JWST) was taken by NIRCam (Near-Infrared Camera) for the JWST Advanced Deep Extragalactic Survey, or JADES, program. NIRCam data was used to determine which galaxies to study further with spectroscopic observations. One of these galaxies, JADES-GS-z14-0 (shown in the excerpt), was determined to be at a redshift of 14.32 (+0.08/-0.20), making it the current record holder for the most distant known galaxy. This corresponds to a time less than 300 million years after the Big Bang. Credits: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)
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This infrared image from NASA’s James Webb Space Telescope (also called Webb or JWST) was taken by NIRCam (Near-Infrared Camera) for the JWST Advanced Deep Extragalactic Survey, or JADES, program. NIRCam data was used to determine which galaxies to study further with spectroscopic observations. One of these galaxies, JADES-GS-z14-0 (shown in the excerpt), was determined to be at a redshift of 14.32 (+0.08/-0.20), making it the current record holder for the most distant known galaxy. This corresponds to a time less than 300 million years after the Big Bang. Credits: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)
An international team of astronomers today announced the discovery of the two oldest and most distant galaxies ever observed, dating back just 300 million years after the Big Bang. These results, obtained using NASA’s James Webb Space Telescope (JWST), mark a major milestone in the study of the early universe.
The discoveries were made by the JWST Advanced Deep Extragalactic Survey (JADES) team. Daniel Eisenstein of the Center for Astrophysics | Harvard & Smithsonian (CfA) is one of the JADES team leaders and principal investigator of the observing program that revealed these galaxies. Ben Johnson and Phillip Cargile, both research scientists at CfA, and Zihao Wu, a PhD at Harvard. student at CfA, also played an important role.
Due to the expansion of the universe, light from distant galaxies expands to longer wavelengths as it travels. This effect is so extreme for these two galaxies that their ultraviolet light is shifted to infrared wavelengths where only JWST can see it. Because light takes time to travel, more distant galaxies are also seen as they were earlier in time.
The two record-breaking galaxies are called JADES-GS-z14-0 and JADES-GS-z14-1, the former being the more distant of the two. In addition to being the new distance record holder, JADES-GS-z14-0 is remarkable for its size and brightness.
“The size of the galaxy clearly proves that most of the light is produced by large numbers of young stars,” said Eisenstein, a Harvard professor and chair of the department of astronomy, “rather than by material falling on a supermassive black hole in the central galaxy, which would appear much smaller.
The combination of the extreme brightness and the fact that young stars are fueling this high luminosity make JADES-GS-z14-0 the most striking evidence yet found for the rapid formation of large, massive galaxies in the early universe.
“JADES-GS-z14-0 now becomes the archetype of this phenomenon,” says Dr. Stefano Carniani of the Scuola Normale Superiore in Pisa, lead author of the discovery paper. “It is astonishing that the universe could create such a galaxy in just 300 million years.”
Scientists used the Near-Infrared Spectrograph (NIRSpec) on NASA’s James Webb Space Telescope to obtain a spectrum of the distant galaxy JADES-GS-z14-0 to precisely measure its redshift and thus determine its age. The redshift can be determined from the location of a critical wavelength known as the Lyman-alpha break. This galaxy dates back less than 300 million years after the Big Bang. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)
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Scientists used the Near-Infrared Spectrograph (NIRSpec) on NASA’s James Webb Space Telescope to obtain a spectrum of the distant galaxy JADES-GS-z14-0 to precisely measure its redshift and thus determine its age. The redshift can be determined from the location of a critical wavelength known as the Lyman-alpha break. This galaxy dates back less than 300 million years after the Big Bang. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)
Evidence of the existence of surprisingly vigorous early galaxies appeared in the first JWST images and grew in number over the first two years of the mission. This trend goes against the expectations of most astronomers before the launch of JWST about theories of galaxy formation.
JADES-GS-z14-0 was a headache for the JADES team when they first spotted it over a year ago, because it appears close enough in the sky of a galaxy at foreground so the team couldn’t be sure the two weren’t neighbors. But in October 2023, the JADES team performed even more in-depth imaging – five full days with the JWST near-infrared camera on a single field – and used filters designed to better isolate the first galaxies.
“We just didn’t see any plausible way to explain this galaxy as simply being a neighbor of a closer galaxy,” says Dr. Kevin Hainline, a research professor at the University of Arizona.
The galaxy is located in a field where the mid-infrared instrument JWST carried out an ultra-deep observation. Its brightness at intermediate infrared wavelengths is a sign of the emission of hydrogen and even oxygen atoms in the early universe.
“Even though it is so young, the galaxy is already working hard to create the elements that are familiar to us on Earth,” said Zihao Wu, co-author of a second paper on the discovery, led by Jakob Helton, a graduate student at the University. from Arizona.
Emboldened, the team then obtained a spectrum of each galaxy and confirmed their hopes that JADES-GS-z14-0 was indeed a record galaxy and that the weakest candidate, JADES-GS-z14-1, was almost as far. .
A third article led by Brant Robertson, professor at the University of California at Santa Cruz, and Ben Johnson, studies the evolution of this first population of galaxies.
“This amazing object shows that the formation of galaxies in the early universe is very rapid and intense,” Johnson said, “and JWST will allow us to find more of these galaxies, perhaps when the universe was even younger . This is a wonderful opportunity to study how galaxies are born.
All three articles are currently available on the arXiv preprint server.
More information:
A bright cosmic dawn: spectroscopic confirmation of two luminous galaxies at z∼14, arXiv:2405.18485 (astro-ph.GA) arxiv.org/abs/2405.18485
JWST/MIRI photometric detection at 7.7 μm of the stellar continuum and nebular emission in a galaxy at z>14, arXiv:2405.18462 (astro-ph.GA) arxiv.org/abs/2405.18462
Brant Robertson et al, The first galaxies in the field of JADES origins: luminosity function and density of the cosmic star formation rate 300 Myr after the Big Bang, arXiv (2023). DOI: 10.48550/arxiv.2312.10033
Journal information:
arXiv