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Kavli Institute for Cosmology, Cambridge

 

A photon caught in two places at once could destroy the multiverse

Mon, 26/05/2025 - 17:28

The idea of a multiverse of universes is derived from a particular interpretation of quantum mechanics, but now a new twist on a classic experiment says it is time to put the idea to bed

Physicists are waging a cosmic battle over the nature of dark energy

Mon, 26/05/2025 - 17:28

Results from the Dark Energy Spectroscopic Instrument (DESI) suggest that dark energy, a mysterious force in the universe, is changing over time. This would completely re-write our understanding of the cosmos - but now other physicists are challenging this view

Large gas inflow driven by a matured galactic bar in the early Universe

Thu, 22/05/2025 - 08:34

Nature, Published online: 21 May 2025; doi:10.1038/s41586-025-08914-2

Gas distribution and motion patterns driven by a galactic bar of the J0107a dusty star-forming galaxy have analogues in local bars, indicating that similar processes of active star formation were already operating 11.1 billion years ago.

Earliest galaxy ever seen offers glimpse of the nascent universe

Wed, 21/05/2025 - 09:54

The galaxy MoM-z14 dates back to 280 million years after the big bang, and the prevalence of such early galaxies is puzzling astronomers

How dark energy findings may inspire a new generation of physics nerds

Fri, 16/05/2025 - 10:05

The discovery of the cosmic acceleration problem truly inspired me as a teenage physics nerd. Recent, related revelations about dark energy will hopefully capture the interest of today’s young science geeks, says Chanda Prescod-Weinstein

Scientists in a race to discover why the Universe exists

Tue, 13/05/2025 - 10:07

Researchers in the US and Japan are racing to build new particle detectors that they hope will explain why the Universe exists.

Why physicists keep trying to get rid of space-time entirely

Wed, 07/05/2025 - 10:01

Physicists are trying to ditch the concept of space-time – the supposed fabric of physical reality. Quantum columnist Karmela Padavic-Callaghan explains why

Dark energy bombshell sparks race to find a new model of the universe

Sat, 03/05/2025 - 18:38

‘Shocking’ results from a major astronomical study have raised doubts about the standard model of cosmology, forcing scientists to consider new ways of understanding dark energy and gravity

The 'impossible' particle hinting at the universe's biggest secrets

Tue, 29/04/2025 - 10:23

Neutrinos have always been hard to explain – and now the detection of one so energetic it shouldn't exist may help illuminate the strangest corners of the cosmos

‘Dark matter’, 'Big Bang' and ‘spin’: how physics terms can confuse researchers

Wed, 23/04/2025 - 10:32

Nature, Published online: 22 April 2025; doi:10.1038/d41586-025-01089-w

In episode three of What's in a name we look at how ideas can be lost in translation when physicists try to name the unknown.

Top quarks spotted at mega-detector could reveal clues to early Universe

Fri, 11/04/2025 - 14:25

Nature, Published online: 10 April 2025; doi:10.1038/d41586-025-01075-2

Heaviest known elementary particles and their antimatter counterparts are detected after nuclear smash-ups at the Large Hadron Collider.

FAST Drift Scan Survey for HI Intensity Mapping. II. Stacking-based Beam Construction of the 19-feed Array at $1.4$ GHz

Thu, 10/04/2025 - 10:27
arXiv:2412.02582v2 Announce Type: replace Abstract: Neutral hydrogen (HI) intensity mapping (IM) presents great promise for future cosmological large-scale structure surveys. However, a major challenge for HIIM cosmological studies is to accurately subtract the foreground contamination. An accurate beam model is crucial for improving the quality of foreground subtraction. In this work, we develop a stacking-based beam reconstruction method utilizing the radio continuum point sources within the drift-scan field. Based on the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we employ two sets of drift-scan survey data and merge the measurements to construct the beam patterns of the 19 FAST L-band feeds. To model the beams, we utilize the Zernike polynomial (ZP), which effectively captures asymmetric features of the main beam and the different side lobes. Due to the symmetric location of the beams, the main features of the beams are closely related to the distance from the center of the feed array, e.g., as the distance increases, side lobes become more pronounced. This modeling pipeline leverages the stable drift-scan data to extract beam patterns while accounting for and excluding the reflector's changing effects. It provides a more accurate measurement beam and a more precise model beam for FAST HIIM cosmology surveys.

Space could emerge from time

Wed, 09/04/2025 - 10:29

An investigation of the changing behaviour of a single quantum bit through time has uncovered a tantalising similarity to the geometry of three-dimensional space

How nothing could destroy the universe

Wed, 02/04/2025 - 09:21

The concept of nothing once sparked a 1000-year-long war, today it might explain dark energy and nothingness even has the potential to destroy the universe, explains physicist Antonio Padilla

BBC Inside Science

Fri, 28/03/2025 - 11:52

How a ‘dark energy’ experiment could upend Einstein's theory of the universe.

A lighthouse galaxy shines unexpectedly through the fog of the cosmic dawn

Thu, 27/03/2025 - 10:47

Nature, Published online: 26 March 2025; doi:10.1038/d41586-025-00899-2

Ultraviolet light from a galaxy observed when the Universe was just 330 million years old has intriguing implications for understanding how the first generations of stars and black holes were formed.

An early hint of cosmic dawn has been seen in a distant galaxy

Thu, 27/03/2025 - 10:45

A galaxy inside a bubble may be evidence that the universe was starting to become transparent 330 million years after the big bang

NASA’s Webb Sees Galaxy Mysteriously Clearing Fog of Early Universe

Thu, 27/03/2025 - 10:45
Explore This Section 5 Min Read NASA’s Webb Sees Galaxy Mysteriously Clearing Fog of Early Universe The incredibly distant galaxy JADES-GS-z13-1, observed just 330 million years after the big bang, was initially discovered with deep imaging from NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera). Full image below. Credits:
NASA, ESA, CSA, JADES Collaboration, J. Witstok (University of Cambridge/University of Copenhagen), P. Jakobsen (University of Copenhagen), A. Pagan (STScI), M. Zamani (ESA/Webb)

Using the unique infrared sensitivity of NASA’s James Webb Space Telescope, researchers can examine ancient galaxies to probe secrets of the early universe. Now, an international team of astronomers has identified bright hydrogen emission from a galaxy in an unexpectedly early time in the universe’s history. The surprise finding is challenging researchers to explain how this light could have pierced the thick fog of neutral hydrogen that filled space at that time.

The Webb telescope discovered the incredibly distant galaxy JADES-GS-z13-1, observed to exist just 330 million years after the big bang, in images taken by Webb’s NIRCam (Near-Infrared Camera) as part of the James Webb Space Telescope Advanced Deep Extragalactic Survey (JADES). Researchers used the galaxy’s brightness in different infrared filters to estimate its redshift, which measures a galaxy’s distance from Earth based on how its light has been stretched out during its journey through expanding space.

Image A: JADES-GS-z13-1 in the GOODS-S field (NIRCam Image) The incredibly distant galaxy JADES-GS-z13-1, observed just 330 million years after the big bang, was initially discovered with deep imaging from NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera). Now, an international team of astronomers definitively has identified powerful hydrogen emission from this galaxy at an unexpectedly early period in the universe’s history. JADES-GS-z-13 has a redshift (z) of 13, which is an indication of its age and distance. NASA, ESA, CSA, JADES Collaboration, J. Witstok (University of Cambridge/University of Copenhagen), P. Jakobsen (University of Copenhagen), A. Pagan (STScI), M. Zamani (ESA/Webb) Image B: JADES-GS-z13-1 (NIRCam Close-Up) This image shows the galaxy JADES GS-z13-1 (the red dot at center), imaged with NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) as part of the JWST Advanced Deep Extragalactic Survey (JADES) program. These data from NIRCam allowed researchers to identify GS-z13-1 as an incredibly distant galaxy, and to put an estimate on its redshift value. Webb’s unique infrared sensitivity is necessary to observe galaxies at this extreme distance, whose light has been shifted into infrared wavelengths during its long journey across the cosmos. NASA, ESA, CSA, JADES Collaboration, J. Witstok (University of Cambridge/University of Copenhagen), P. Jakobsen (University of Copenhagen), M. Zamani (ESA/Webb)

The NIRCam imaging yielded an initial redshift estimate of 12.9. Seeking to confirm its extreme redshift, an international team lead by Joris Witstok of the University of Cambridge in the United Kingdom, as well as the Cosmic Dawn Center and the University of Copenhagen in Denmark, then observed the galaxy using Webb’s Near-Infrared Spectrograph instrument.

In the resulting spectrum, the redshift was confirmed to be 13.0. This equates to a galaxy seen just 330 million years after the big bang, a small fraction of the universe’s present age of 13.8 billion years old. But an unexpected feature stood out as well: one specific, distinctly bright wavelength of light, known as Lyman-alpha emission, radiated by hydrogen atoms. This emission was far stronger than astronomers thought possible at this early stage in the universe’s development.

“The early universe was bathed in a thick fog of neutral hydrogen,” explained Roberto Maiolino, a team member from the University of Cambridge and University College London. “Most of this haze was lifted in a process called reionization, which was completed about one billion years after the big bang. GS-z13-1 is seen when the universe was only 330 million years old, yet it shows a surprisingly clear, telltale signature of Lyman-alpha emission that can only be seen once the surrounding fog has fully lifted. This result was totally unexpected by theories of early galaxy formation and has caught astronomers by surprise.”

Image C: JADES-GS-z13-1 Spectrum Graphic NASA’s James Webb Space Telescope has detected unexpected light from a distant galaxy. The galaxy JADES-GS-z13-1, observed just 330 million years after the big bang (corresponding to a redshift of z=13.05), shows bright emission from hydrogen known as Lyman-alpha emission. This is surprising because that emission should have been absorbed by a dense fog of neutral hydrogen that suffused the early universe. NASA, ESA, CSA, J. Witstok (University of Cambridge, University of Copenhagen), J. Olmsted (STScI)

Before and during the era of reionization, the immense amounts of neutral hydrogen fog surrounding galaxies blocked any energetic ultraviolet light they emitted, much like the filtering effect of colored glass. Until enough stars had formed and were able to ionize the hydrogen gas, no such light — including Lyman-alpha emission — could escape from these fledgling galaxies to reach Earth. The confirmation of Lyman-alpha radiation from this galaxy, therefore, has great implications for our understanding of the early universe.

“We really shouldn’t have found a galaxy like this, given our understanding of the way the universe has evolved,” said Kevin Hainline, a team member from the University of Arizona. “We could think of the early universe as shrouded with a thick fog that would make it exceedingly difficult to find even powerful lighthouses peeking through, yet here we see the beam of light from this galaxy piercing the veil. This fascinating emission line has huge ramifications for how and when the universe reionized.”

The source of the Lyman-alpha radiation from this galaxy is not yet known, but it may include the first light from the earliest generation of stars to form in the universe.

“The large bubble of ionized hydrogen surrounding this galaxy might have been created by a peculiar population of stars — much more massive, hotter, and more luminous than stars formed at later epochs, and possibly representative of the first generation of stars,” said Witstok. A powerful active galactic nucleus, driven by one of the first supermassive black holes, is another possibility identified by the team.

This research was published Wednesday in the journal Nature.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

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Media Contacts

Laura Betz – laura.e.betz@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Bethany DownerBethany.Downer@esawebb.org
ESA/Webb, Baltimore, Md.

Christine Pulliamcpulliam@stsci.edu
Space Telescope Science Institute, Baltimore, Md.

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Share Details Last Updated Mar 26, 2025 Editor Marty McCoy Contact Laura Betz laura.e.betz@nasa.gov Related Terms

Dark Energy experiment challenges Einstein's theory of Universe

Thu, 27/03/2025 - 10:44

New research could force a fundamental rethink of the nature of space and time.

Webb Telescope sees galaxy in mysteriously clearing fog of early Universe

Thu, 27/03/2025 - 10:43

A key goal of the NASA/ESA/CSA James Webb Space Telescope has been to see further than ever before into the distant past of our Universe, when the first galaxies were forming after the Big Bang, a period know as cosmic dawn.

Researchers studying one of those very early galaxies have now made a discovery in the spectrum of its light, that challenges our established understanding of the Universe’s early history. Their results are reported in the journal Nature.

Webb discovered the incredibly distant galaxy JADES-GS-z13-1, observed at just 330 million years after the Big Bang. Researchers used the galaxy’s brightness in different infrared filters to estimate its redshift, which measures a galaxy’s distance from Earth based on how its light has been stretched out during its journey through expanding space.

The NIRCam imaging yielded an initial redshift estimate of 12.9. To confirm its extreme redshift, an international team led by Dr Joris Witstok, previously of the University of Cambridge’s Kavli Institute for Cosmology, observed the galaxy using Webb’s Near-Infrared Spectrograph (NIRSpec) instrument.

The resulting spectrum confirmed the redshift to be 13.0. This equates to a galaxy seen just 330 million years after the Big Bang, a small fraction of the Universe’s present age of 13.8 billion years.

But an unexpected feature also stood out: one specific, distinctly bright wavelength of light, identified as the Lyman-α emission radiated by hydrogen atoms. This emission was far stronger than astronomers thought possible at this early stage in the Universe’s development.

“The early Universe was bathed in a thick fog of neutral hydrogen,” said co-author Professor Roberto Maiolino from Cambridge’s Kavli Institute for Cosmology. “Most of this haze was lifted in a process called reionisation, which was completed about one billion years after the Big Bang.

“GS-z13-1 is seen when the Universe was only 330 million years old, yet it shows a surprisingly clear, telltale signature of Lyman-α emission that can only be seen once the surrounding fog has fully lifted. This result was totally unexpected by theories of early galaxy formation and has caught astronomers by surprise.”

Before and during the epoch of reionisation, neutral hydrogen fog surrounding galaxies blocked any energetic ultraviolet light they emitted, much like the filtering effect of coloured glass. Until enough stars had formed and were able to ionise the hydrogen gas, no such light — including Lyman-α emission — could escape from these fledgling galaxies to reach Earth.

The confirmation of Lyman-α radiation from this galaxy has great implications for our understanding of the early Universe. “We really shouldn’t have found a galaxy like this, given our understanding of the way the Universe has evolved,” said co-author Kevin Hainline from the University of Arizona. “We could think of the early Universe as shrouded with a thick fog that would make it exceedingly difficult to find even powerful lighthouses peeking through, yet here we see the beam of light from this galaxy piercing the veil.”

The source of the Lyman-α radiation from this galaxy is not yet known, but it may include the first light from the earliest generation of stars to form in the Universe. “The large bubble of ionised hydrogen surrounding this galaxy might have been created by a peculiar population of stars — much more massive, hotter and more luminous than stars formed at later epochs, and possibly representative of the first generation of stars,” said Witstok, who is now based at the Cosmic Dawn Center at the University of Copenhagen. A powerful active galactic nucleus, driven by one of the first supermassive black holes, is another possibility identified by the team.

The team plans further follow-up observations of GS-z13-1, aiming to obtain more information about the nature of this galaxy and origin of its strong Lyman-α radiation. Whatever the galaxy is concealing, it is certain to illuminate a new frontier in cosmology.

JWST is an international partnership between NASA, ESA and the Canadian Space Agency (CSA). The data for this result were captured as part of the JWST Advanced Deep Extragalactic Survey (JADES).

Reference:
Joris Witstok et al. ‘Witnessing the onset of reionization through Lyman-α emission at redshift 13.’ Nature (2025). DOI: 10.1038/s41586-025-08779-5

Adapted from an ESA media release.

Astronomers have identified a bright hydrogen emission from a galaxy in the very early Universe. The surprise finding is challenging researchers to explain how this light could have pierced the thick fog of neutral hydrogen that filled space at that time.

This result was totally unexpected by theories of early galaxy formation and has caught astronomers by surpriseRoberto MaiolinoESA/Webb, NASA, STScI, CSA, JADES CollaborationJADES-GS-z13-1 in the GOODS-S field


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