This infrared image from NASA’s James Webb Space Telescope (also called Webb or JWST) was taken by the NIRCam (Near Infrared Camera) for the JWST Advanced Deep Extragalactic Survey, or JADES, program. The NIRCam data were used to determine which galaxies to investigate further with spectroscopic observations. One such galaxy, JADES-GS-z14-0 (shown in the sample), was determined 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. Courtesy of: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Taccella (Cambridge), Phil Cargill (CfA)
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This infrared image from NASA’s James Webb Space Telescope (also called Webb or JWST) was taken by the NIRCam (Near Infrared Camera) for the JWST Advanced Deep Extragalactic Survey, or JADES, program. The NIRCam data were used to determine which galaxies to investigate further with spectroscopic observations. One such galaxy, JADES-GS-z14-0 (shown in the sample), was determined 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. Courtesy of: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Taccella (Cambridge), Phil Cargill (CfA)
An international team of astronomers today announced the discovery of the two earliest and most distant galaxies ever seen, dating back just 300 million years after the Big Bang. These results, 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 Philip Cargill, both researchers at CfA, and Zihao Wu, PhD from Harvard. student at CfA, also played an important role.
Due to the expansion of the universe, light from distant galaxies is stretched 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 named JADES-GS-z14-0 and JADES-GS-z14-1, the former being the more distant of the two. Besides being the new distance record holder, the JADES-GS-z14-0 is notable for how big and bright it is.
“The size of the galaxy makes it clear that most of the light is produced by a large number of young stars,” said Eisenstein, a Harvard professor and chairman of the astronomy department, “rather than material falling onto a supermassive black hole at the galactic center , which will appear much smaller.”
The combination of the extraordinary brightness and the fact that young stars are fueling this high brightness makes JADES-GS-z14-0 the most stunning evidence yet discovered of the rapid formation of large, massive galaxies in the early universe.
“JADES-GS-z14-0 is now becoming the archetype of this phenomenon,” said Dr. Stefano Carniani of the Scuola Normale Superiore in Pisa, lead author of the discovery paper. “It’s amazing that the universe could create such a galaxy in just 300 million years.
Scientists used NIRSpec (Near Infrared Spectrograph) 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 therefore determine its age. The redshift can be determined from the location of a critical wavelength known as the Lyman-alpha cutoff. This galaxy dates back to less than 300 million years after the Big Bang. Courtesy: NASA, ESA, CSA, Joseph Olmsted (STScI)
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Scientists used NIRSpec (Near Infrared Spectrograph) 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 therefore determine its age. The redshift can be determined from the location of a critical wavelength known as the Lyman-alpha cutoff. This galaxy dates back to less than 300 million years after the Big Bang. Courtesy: NASA, ESA, CSA, Joseph Olmsted (STScI)
Evidence of surprisingly strong early galaxies appeared even in the first JWST images and increased during the first two years of the mission. This trend contradicts the expectations that most astronomers had before the JWST launch of theories of galaxy formation.
JADES-GS-z14-0 was a puzzle for the JADES team when it was first spotted more than a year ago, as it appeared close enough in the sky to a foreground galaxy that the team could not be sure that the two are neighbors. But in October 2023, the JADES team conducted even deeper imaging—five full days with the JWST near-infrared camera in just one field—and used filters designed to better isolate the earliest galaxies.
“We just couldn’t see any plausible way to explain this galaxy as just a neighbor of a closer galaxy,” said Dr. Kevin Heinlein, a research professor at the University of Arizona.
The galaxy is located in a field where the JWST Mid-Infrared Instrument made an ultra-deep observation. Its brightness at mid-infrared wavelengths is a sign of emission from hydrogen and even oxygen atoms in the early universe.
“Even though it’s so young, the galaxy is already hard at work creating the elements we know on Earth,” said Zihao Wu, co-author of a second paper on the discovery, led by Jacob Helton, a graduate student at the University of Arizona.
Encouraged, the team then obtained a spectrum from each galaxy and confirmed their hopes that JADES-GS-z14-0 was indeed the record-breaking galaxy and that the fainter candidate, JADES-GS-z14-1, was almost as far away.
A third paper, led by Brant Robertson, a professor at UC Santa Cruz, and Ben Johnson, studies the evolution of this early population of galaxies.
“This amazing object shows that galaxy formation in the early universe was very fast and intense,” Johnson said, “and JWST will allow us to discover more of these galaxies, perhaps when the universe was even younger.” This is a wonderful opportunity to study how galaxies begin.”
All three documents are currently available at arXiv prepress server.
More info:
A brilliant 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 earliest galaxies in the JADES origin field: luminosity and density function of the cosmic star formation rate 300 Myr after the Big Bang, arXiv (2023). DOI: 10.48550/arxiv.2312.10033
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