Astronomers NIR Specs The NASA/ESA/CSA James Webb Space Telescope (Near-Infrared Spectrometer) instrument Obtained Spectrum of the record-breaking galaxy JADES-GS-z14-0, observed just 290 million years after the Big Bang. Redshift It’s about 14, a measure of how much the galaxy’s light has been stretched by the expansion of the universe.
This infrared image from Webb’s NIRCam shows the record-breaking galaxy JADES-GS-z14-0. Image credit: NASA / ESA / CSA / STScI / B. Robertson, UC Santa Cruz / B. Johnson, CfA / S. Tacchella, Cambridge / P. Cargile, CfA.
JADES-GS-z14-0, located in the constellation Fornax, JWST: Advanced Deep Extragalactic Exploration (Jade).
The galaxy is much brighter than expected, with a resolved radius of 260 parsecs (848 light years).
The discovery proves that luminous galaxies were already in existence 300 million years after the Big Bang, and that they are more common than expected before Webb.
“The Webb instrument is designed to discover and understand the oldest galaxies, and in its first year of observing as part of JADES, it has found hundreds of candidate galaxies spanning the first 650 million years after the Big Bang,” said Dr. Stefano Carniani of the École Normale Supérieure in Pisa, Italy, and Dr. Kevin Hainline of the University of Arizona, Tucson.
“Early in 2023, we discovered a galaxy in our data with strong evidence of being at a redshift greater than 14. This was very exciting, but some properties of its source made us wary.”
“The source was incredibly bright, something not expected in such a distant galaxy, and it was so close to another galaxy that the two appeared to be part of a single, larger object.”
“When Webb observed the source again in October 2023 as part of the JADES Origins Field, NIR Cam (Near-infrared camera) filters further supported the high-redshift hypothesis.”
“We knew we needed a spectrum, because anything we learn would be of immense scientific importance, either as a new milestone in Webb’s study of the early universe or as a mysterious outlier in a middle-aged galaxy.”
“In January 2024, NIRSpec observed JADES-GS-z14-0 for almost 10 hours, and when the spectrum was first processed, there was unequivocal evidence that the galaxy is indeed at redshift 14.32, breaking the previous record for the most distant galaxy, JADES-GS-z13-0.”
“Seeing this spectrum was very exciting for the whole team, given that its source remained a mystery.”
“This discovery was not just a new distance record for our team. The most important thing about JADES-GS-z14-0 is that it shows that at this distance, this galaxy must be intrinsically very luminous.”
“The images show that the source is more than 1,600 light-years in diameter, proving that the light we are seeing is coming primarily from young stars, and not from the vicinity of a growing supermassive black hole.”
“This much starlight suggests that the galaxy’s mass is hundreds of millions of times that of the Sun!”
“This raises the question: How could nature create such a bright, massive and large galaxy in less than 300 million years?”
“The data reveal other important aspects of this remarkable galaxy,” the astronomers said.
“We found that the galaxy’s color is not inherently blue, which indicates that even at its very earliest stages, some of its light is being reddened by dust.”
They also confirmed that JADES-GS-z14-0 was detected at Webb’s longer wavelengths. Milli (mid-infrared observation instrument), a remarkable achievement considering its distance.
MIRI’s observations cover wavelengths of light emitted in the visible range that are redshifted and cannot be seen by Webb’s near-infrared instrument.
According to the analysis, the brightness of the source suggested by the MIRI observations exceeds that estimated from measurements by other Webb instruments, indicating the presence of strong ionized gas emission in the galaxy in the form of bright emission lines from hydrogen and oxygen.
The presence of oxygen so early in the galaxy’s life was surprising, suggesting that several generations of very massive stars had already died before the galaxy was observed.
“Taken together, all these observations show that JADES-GS-z14-0 is different from the types of galaxy predicted to exist in the early universe by theoretical models and computer simulations,” the researchers said.
“Given the observed luminosity of a source, we can predict how it will grow over cosmic time. So far, we have not found a suitable analogue among the hundreds of other galaxies we have observed at high redshifts in our survey.”
“Because the region of sky we searched to find JADES-GS-z14-0 is relatively small, its discovery has a significant impact on the predicted number of luminous galaxies seen in the early universe, as discussed in a separate, concurrent JADES study.”
“Webb’s observations will enable astronomers to discover many more such luminous galaxies over the next decade, and perhaps sooner.”
“We’re excited to see the incredible diversity of galaxies present in Cosmic Dawn!”
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Stefano Carniani others2024. A shining cosmic dawn: spectroscopic confirmation of two luminous galaxies at z ∼ 14. arXiv:2405.18485
Source: www.sci.news
