̽��ֱ�� of Cambridge - James Webb Space Telescope (JWST)

Strongest hints yet of biological activity outside the solar system

sc604 — Thu, 17 Apr 2025 04:09:34 +0000

Astronomers have detected the most promising signs yet of a possible biosignature outside the solar system, although they remain cautious.

Webb Telescope sees galaxy in mysteriously clearing fog of early Universe

sc604 — Wed, 26 Mar 2025 16:00:00 +0000

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.

̽��ֱ��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 ̽��ֱ�� of Cambridge’s Kavli Institute for Cosmology, observed the galaxy using Webb’s Near-Infrared Spectrograph (NIRSpec) instrument.

̽��ֱ��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.

“ ̽��ֱ��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.

̽��ֱ��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 ̽��ֱ�� 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.”

̽��ֱ��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. “ ̽��ֱ��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 ̽��ֱ�� of Copenhagen. A powerful active galactic nucleus, driven by one of the first supermassive black holes, is another possibility identified by the team.

̽��ֱ��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). ̽��ֱ��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. ̽��ֱ��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 surprise

Roberto Maiolino

ESA/Webb, NASA, STScI, CSA, JADES Collaboration

JADES-GS-z13-1 in the GOODS-S field

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Massive black hole in the early universe spotted taking a ‘nap’ after overeating

sc604 — Wed, 18 Dec 2024 16:00:00 +0000

Like a bear gorging itself on salmon before hibernating for the winter, or a much-needed nap after Christmas dinner, this black hole has overeaten to the point that it is lying dormant in its host galaxy.

An international team of astronomers, led by the ̽��ֱ�� of Cambridge, used the NASA/ESA/CSA James Webb Space Telescope to detect this black hole in the early universe, just 800 million years after the Big Bang.

̽��ֱ��black hole is huge – 400 million times the mass of our Sun – making it one of the most massive black holes discovered by Webb at this point in the universe’s development. ̽��ֱ��black hole is so enormous that it makes up roughly 40% of the total mass of its host galaxy: in comparison, most black holes in the local universe are roughly 0.1% of their host galaxy mass.

However, despite its gigantic size, this black hole is eating, or accreting, the gas it needs to grow at a very low rate – about 100 times below its theoretical maximum limit – making it essentially dormant.

Such an over-massive black hole so early in the universe, but one that isn’t growing, challenges existing models of how black holes develop. However, the researchers say that the most likely scenario is that black holes go through short periods of ultra-fast growth, followed by long periods of dormancy. Their results are reported in the journal Nature.

When black holes are ‘napping’, they are far less luminous, making them more difficult to spot, even with highly sensitive telescopes such as Webb. Black holes cannot be directly observed, but instead they are detected by the tell-tale glow of a swirling accretion disc, which forms near the black hole’s edges. When black holes are actively growing, the gas in the accretion disc becomes extremely hot and starts to glow and radiate energy in the ultraviolet range.

“Even though this black hole is dormant, its enormous size made it possible for us to detect,” said lead author Ignas Juodžbalis from Cambridge’s Kavli Institute for Cosmology. “Its dormant state allowed us to learn about the mass of the host galaxy as well. ̽��ֱ��early universe managed to produce some absolute monsters, even in relatively tiny galaxies.”

According to standard models, black holes form from the collapsed remnants of dead stars and accrete matter up to a predicted limit, known as the Eddington limit, where the pressure of radiation on matter overcomes the gravitational pull of the black hole. However, the sheer size of this black hole suggests that standard models may not adequately explain how these monsters form and grow.

“It’s possible that black holes are ‘born big’, which could explain why Webb has spotted huge black holes in the early universe,” said co-author Professor Roberto Maiolino, from the Kavli Institute and Cambridge’s Cavendish Laboratory. “But another possibility is they go through periods of hyperactivity, followed by long periods of dormancy.”

Working with colleagues from Italy, the Cambridge researchers conducted a range of computer simulations to model how this dormant black hole could have grown to such a massive size so early in the universe. They found that the most likely scenario is that black holes can exceed the Eddington limit for short periods, during which they grow very rapidly, followed by long periods of inactivity: the researchers say that black holes such as this one likely eat for five to ten million years, and sleep for about 100 million years.

“It sounds counterintuitive to explain a dormant black hole with periods of hyperactivity, but these short bursts allow it to grow quickly while spending most of its time napping,” said Maiolino.

Because the periods of dormancy are much longer than the periods of ultra-fast growth, it is in these periods that astronomers are most likely to detect black holes. “This was the first result I had as part of my PhD, and it took me a little while to appreciate just how remarkable it was,” said Juodžbalis. “It wasn’t until I started speaking with my colleagues on the theoretical side of astronomy that I was able to see the true significance of this black hole.”

Due to their low luminosities, dormant black holes are more challenging for astronomers to detect, but the researchers say this black hole is almost certainly the tip of a much larger iceberg, if black holes in the early universe spend most of their time in a dormant state.

“It’s likely that the vast majority of black holes out there are in this dormant state – I’m surprised we found this one, but I’m excited to think that there are so many more we could find,” said Maiolino.

̽��ֱ��observations were obtained as part of the JWST Advanced Deep Extragalactic Survey (JADES). ̽��ֱ��research was supported in part by the European Research Council and the Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI).

Reference:
Ignas Juodžbalis et al. ‘A dormant overmassive black hole in the early Universe.’ Nature (2024). DOI: 10.1038/s41586-024-08210-5

Scientists have spotted a massive black hole in the early universe that is ‘napping’ after stuffing itself with too much food.

Jiarong Gu

Artist’s impression of a black hole during one of its short periods of rapid growth

Yes

‘Inside-out’ galaxy growth observed in the early universe

sc604 — Fri, 11 Oct 2024 09:00:00 +0000

This galaxy is one hundred times smaller than the Milky Way, but is surprisingly mature for so early in the universe. Like a large city, this galaxy has a dense collection of stars at its core but becomes less dense in the galactic ‘suburbs’. And like a large city, this galaxy is starting to sprawl, with star formation accelerating in the outskirts.

This is the earliest-ever detection of inside-out galactic growth. Until Webb, it had not been possible to study galaxy growth so early in the universe’s history. Although the images obtained with Webb represent a snapshot in time, the researchers, led by the ̽��ֱ�� of Cambridge, say that studying similar galaxies could help us understand how they transform from clouds of gas into the complex structures we observe today. ̽��ֱ��results are reported in the journal Nature Astronomy.

“ ̽��ֱ��question of how galaxies evolve over cosmic time is an important one in astrophysics,” said co-lead author Dr Sandro Tacchella from Cambridge’s Cavendish Laboratory. “We’ve had lots of excellent data for the last ten million years and for galaxies in our corner of the universe, but now with Webb, we can get observational data from billions of years back in time, probing the first billion years of cosmic history, which opens up all kinds of new questions.”

̽��ֱ��galaxies we observe today grow via two main mechanisms: either they pull in, or accrete, gas to form new stars, or they grow by merging with smaller galaxies. Whether different mechanisms were at work in the early universe is an open question which astronomers are hoping to address with Webb.

“You expect galaxies to start small as gas clouds collapse under their own gravity, forming very dense cores of stars and possibly black holes,” said Tacchella. “As the galaxy grows and star formation increases, it’s sort of like a spinning figure skater: as the skater pulls in their arms, they gather momentum, and they spin faster and faster. Galaxies are somewhat similar, with gas accreting later from larger and larger distances spinning the galaxy up, which is why they often form spiral or disc shapes.”

This galaxy, observed as part of the JADES (JWST Advanced Extragalactic Survey) collaboration, is actively forming stars in the early universe. It has a highly dense core, which despite its relatively young age, is of a similar density to present-day massive elliptical galaxies, which have 1000 times more stars. Most of the star formation is happening further away from the core, with a star-forming ‘clump’ even further out.

̽��ֱ��star formation activity is strongly rising toward the outskirts, as the star formation spreads out and the galaxy grows. This type of growth had been predicted with theoretical models, but with Webb, it is now possible to observe it.

“One of the many reasons that Webb is so transformational to us as astronomers is that we’re now able to observe what had previously been predicted through modelling,” said co-author William Baker, a PhD student at the Cavendish. “It’s like being able to check your homework.”

Using Webb, the researchers extracted information from the light emitted by the galaxy at different wavelengths, which they then used to estimate the number of younger stars versus older stars, which is converted into an estimate of the stellar mass and star formation rate.

Because the galaxy is so compact, the individual images of the galaxy were ‘forward modelled’ to take into account instrumental effects. Using stellar population modelling that includes prescriptions for gas emission and dust absorption, the researchers found older stars in the core, while the surrounding disc component is undergoing very active star formation. This galaxy doubles its stellar mass in the outskirts roughly every 10 million years, which is very rapid: the Milky Way galaxy doubles its mass only every 10 billion years.

̽��ֱ��density of the galactic core, as well as the high star formation rate, suggest that this young galaxy is rich with the gas it needs to form new stars, which may reflect different conditions in the early universe.

“Of course, this is only one galaxy, so we need to know what other galaxies at the time were doing,” said Tacchella. “Were all galaxies like this one? We’re now analysing similar data from other galaxies. By looking at different galaxies across cosmic time, we may be able to reconstruct the growth cycle and demonstrate how galaxies grow to their eventual size today.”

Reference:
William M. Baker, Sandro Tacchella, et al. ‘A core in a star-forming disc as evidence of inside-out growth in the early Universe.’ Nature Astronomy (2024). DOI: 10.1038/s41550-024-02384-8

Astronomers have used the NASA/ESA James Webb Space Telescope (JWST) to observe the ‘inside-out’ growth of a galaxy in the early universe, only 700 million years after the Big Bang.

NASA, ESA, CSA, Sandro Tacchella, William Baker, Ovee Tulaskar

Galaxy NGC 1549, seen today and possibly 13 billion years ago

Yes

Astronomers detect black hole ‘starving’ its host galaxy to death

sc604 — Thu, 12 Sep 2024 11:36:56 +0000

̽��ֱ��international team, co-led by the ̽��ֱ�� of Cambridge, used Webb to observe a galaxy roughly the size of the Milky Way in the early universe, about two billion years after the Big Bang. Like most large galaxies, it has a supermassive black hole at its centre. However, this galaxy is essentially ‘dead’: it has mostly stopped forming new stars.

“Based on earlier observations, we knew this galaxy was in a quenched state: it’s not forming many stars given its size, and we expect there is a link between the black hole and the end of star formation,” said co-lead author Dr Francesco D’Eugenio from Cambridge’s Kavli Institute for Cosmology. “However, until Webb, we haven’t been able to study this galaxy in enough detail to confirm that link, and we haven’t known whether this quenched state is temporary or permanent.”

This galaxy, officially named GS-10578 but nicknamed ‘Pablo’s Galaxy’ after the colleague who decided to observe it in detail, is massive for such an early period in the universe: its total mass is about 200 billion times the mass of our Sun, and most of its stars formed between 12.5 and 11.5 billion years ago.

“In the early universe, most galaxies are forming lots of stars, so it’s interesting to see such a massive dead galaxy at this period in time,” said co-author Professor Roberto Maiolino, also from the Kavli Institute for Cosmology. “If it had enough time to get to this massive size, whatever process that stopped star formation likely happened relatively quickly.”

Using Webb, the researchers detected that this galaxy is expelling large amounts of gas at speeds of about 1,000 kilometres per second, which is fast enough to escape the galaxy’s gravitational pull. These fast-moving winds are being ‘pushed’ out of the galaxy by the black hole.

Like other galaxies with accreting black holes, ‘Pablo’s Galaxy’ has fast outflowing winds of hot gas, but these gas clouds are tenuous and have little mass. Webb detected the presence of a new wind component, which could not be seen with earlier telescopes. This gas is colder, which means it’s denser and – crucially – does not emit any light. Webb, with its superior sensitivity, can see these dark gas clouds because they block some of the light from the galaxy behind them.

̽��ֱ��mass of gas being ejected from the galaxy is greater than what the galaxy would require to keep forming new stars. In essence, the black hole is starving the galaxy to death. ̽��ֱ��results are reported in the journal Nature Astronomy.

“We found the culprit,” said D’Eugenio. “ ̽��ֱ��black hole is killing this galaxy and keeping it dormant, by cutting off the source of ‘food’ the galaxy needs to form new stars.”

Although earlier theoretical models had predicted that black holes had this effect on galaxies, before Webb, it had not been possible to detect this effect directly.

Earlier models had predicted that the end of star formation has a violent, turbulent effect on galaxies, destroying their shape in the process. But the stars in this disc-shaped galaxy are still moving in an orderly way, suggesting that this is not always the case.

“We knew that black holes have a massive impact on galaxies, and perhaps it’s common that they stop star formation, but until Webb, we weren’t able to directly confirm this,” said Maiolino. “It’s yet another way that Webb is such a giant leap forward in terms of our ability to study the early universe and how it evolved.”

New observations with the Atacama Large Millimeter-Submillimiter Array (ALMA), targeting the coldest, darkest gas components of the galaxy, will tell us more about if and where any fuel for star formation is still hidden in this galaxy, and what is the effect of the supermassive black hole in the region surrounding the galaxy.

̽��ֱ��research was supported in part by the Royal Society, the European Union, the European Research Council, and the Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI).

Reference:
Francesco D’Eugenio, Pablo G. Pérez-González et al. ‘A fast-rotator post-starburst galaxy quenched by supermassive black-hole feedback at z=3.’ Nature Astronomy (2024). DOI: 10.1038/s41550-024-02345-1

Astronomers have used the NASA/ESA James Webb Space Telescope to confirm that supermassive black holes can starve their host galaxies of the fuel they need to form new stars.

JADES Collaboration

'Pablo's Galaxy'

Yes

Licence type:

Public Domain

Earliest detection of metal challenges what we know about the first galaxies

sc604 — Thu, 06 Jun 2024 14:52:26 +0000

Using the James Webb Space Telescope (JWST), an international team of astronomers led by the ̽��ֱ�� of Cambridge observed a very young galaxy in the early universe and found that it contained surprising amounts of carbon, one of the seeds of life as we know it.

In astronomy, elements heavier than hydrogen or helium are classed as metals. ̽��ֱ��very early universe was almost entirely made up of hydrogen, the simplest of the elements, with small amounts of helium and tiny amounts of lithium.

Every other element that makes up the universe we observe today was formed inside a star. When stars explode as supernovas, the elements they produce are circulated throughout their host galaxy, seeding the next generation of stars. With every new generation of stars and ‘stardust’, more metals are formed, and after billions of years, the universe evolves to a point where it can support rocky planets like Earth and life like us.

̽��ֱ��ability to trace the origin and evolution of metals will help us understand how we went from a universe made almost entirely of just two chemical elements, to the incredible complexity we see today.

“ ̽��ֱ��very first stars are the holy grail of chemical evolution,” said lead author Dr Francesco D’Eugenio, from the Kavli Institute for Cosmology at Cambridge. “Since they are made only of primordial elements, they behave very differently to modern stars. By studying how and when the first metals formed inside stars, we can set a time frame for the earliest steps on the path that led to the formation of life.”

Carbon is a fundamental element in the evolution of the universe, since it can form into grains of dust that clump together, eventually forming into the first planetesimals and the earliest planets. Carbon is also key for the formation of life on Earth.

“Earlier research suggested that carbon started to form in large quantities relatively late – about one billion years after the Big Bang,” said co-author Professor Roberto Maiolino, also from the Kavli Institute. “But we’ve found that carbon formed much earlier – it might even be the oldest metal of all.”

̽��ֱ��team used the JWST to observe a very distant galaxy – one of the most distant galaxies yet observed – just 350 million years after the Big Bang, more than 13 billion years ago. This galaxy is compact and low mass – about 100,000 times less massive than the Milky Way.

“It’s just an embryo of a galaxy when we observe it, but it could evolve into something quite big, about the size of the Milky Way,” said D’Eugenio. “But for such a young galaxy, it’s fairly massive.”

̽��ֱ��researchers used Webb’s Near Infrared Spectrograph (NIRSpec) to break down the light coming from the young galaxy into a spectrum of colours. Different elements leave different chemical fingerprints in the galaxy’s spectrum, allowing the team to determine its chemical composition. Analysis of this spectrum showed a confident detection of carbon, and tentative detections of oxygen and neon, although further observations will be required to confirm the presence of these other elements.

“We were surprised to see carbon so early in the universe, since it was thought that the earliest stars produced much more oxygen than carbon,” said Maiolino. “We had thought that carbon was enriched much later, through entirely different processes, but the fact that it appears so early tells us that the very first stars may have operated very differently.”

According to some models, when the earliest stars exploded as supernovas, they may have released less energy than initially expected. In this case, carbon, which was in the stars’ outer shell and was less gravitationally bound than oxygen, could have escaped more easily and spread throughout the galaxy, while a large amount of oxygen fell back and collapsed into a black hole.

“These observations tell us that carbon can be enriched quickly in the early universe,” said D’Eugenio. “And because carbon is fundamental to life as we know it, it’s not necessarily true that life must have evolved much later in the universe. Perhaps life emerged much earlier – although if there’s life elsewhere in the universe, it might have evolved very differently than it did here on Earth.”

̽��ֱ��results have been accepted for publication in the journal Astronomy & Astrophysics and are based on data obtained within the JWST Advanced Deep Extragalactic Survey (JADES).

̽��ֱ��research was supported in part by the European Research Council, the Royal Society, and the Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI).

Reference:
Francesco D’Eugenio et al. ‘JADES: Carbon enrichment 350 Myr after the Big Bang.’ Astronomy & Astrophysics (in press). DOI: 10.48550/arXiv.2311.09908

Astronomers have detected carbon in a galaxy just 350 million years after the Big Bang, the earliest detection of any element in the universe other than hydrogen.

NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)

Deep field image from JWST

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Earliest, most distant galaxy discovered with James Webb Space Telescope

Anonymous — Thu, 30 May 2024 11:04:20 +0000

Found in a region near the Hubble Ultra Deep Field by the JWST Advanced Deep Extragalactic Survey (JADES) team, these galaxies mark a major milestone in the study of the early Universe.

“These galaxies join a small but growing population of galaxies from the first half billion years of cosmic history where we can really probe the stellar populations and the distinctive patterns of chemical elements within them,” said Dr Francesco D’Eugenio of the Kavli Institute for Cosmology at the ̽��ֱ�� of Cambridge, one of the team behind the discovery.

Because of the expansion of the Universe, the light from distant galaxies stretches to longer wavelength as it travels, an effect known as redshift. In these galaxies, the effect is extreme, stretching by a factor of 15, and moving even the ultraviolet light of the galaxies to infrared wavelengths where only JWST has the capability to see it.

Modern theory holds that galaxies develop in special regions where gravity has concentrated the cosmic gas and dark matter into dense lumps known as ‘halos’. These halos evolved quickly in the early Universe, rapidly merging into more and more massive collections of matter. This fast development is why astronomers are so eager to find yet earlier galaxies: each small increment moves our eyes to a less developed period, where luminous galaxies are even more distinctive and unusual.

̽��ֱ��two newly discovered galaxies have been confirmed spectroscopically. In keeping with the collaboration’s standard naming practice, the galaxies are now known as 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 how big and bright it is. JWST measures the galaxy at over 1,600 light-years in diameter. Many of the most luminous galaxies produce the bulk of their light via gas falling into a supermassive black hole, producing a quasar, but at this size JADES-GS-z14-0 cannot be this. Instead, the researchers believe the light is being produced by young stars.

̽��ֱ��combination of the high luminosity and the stellar origin makes JADES-GS-z14-0 the most distinctive evidence yet found for the rapid formation of large, massive galaxies in the early Universe. This trend runs counter to the pre-JWST expectations of theories of galaxy formation. Evidence for surprisingly vigorous early galaxies appeared even in the first JWST images and has been mounting in the first two years of the mission.

“JADES-GS-z14-0 now becomes the archetype of this phenomenon,” said Dr Stefano Carniani of the Scuola Normale Superiore in Pisa, lead author on the discovery paper. “It is stunning that the Universe can make such a galaxy in only 300 million years.”

Despite its luminosity, JADES-GS-z14-0 was a puzzle for the JADES team when they first spotted it over a year ago, as it appears close enough on the sky to a foreground galaxy that the team couldn’t be sure that the two weren’t neighbours. But in October 2023, the JADES team conducted even deeper imaging—five full days with the JWST Near-Infrared Camera on just one field—to form the “JADES Origins Field.” With the use of filters designed to better isolate the earliest galaxies, confidence grew that JADES-GS-z14-0 was indeed very distant.

“We just couldn’t see any plausible way to explain this galaxy as being merely a neighbour of the more nearby galaxy,” said Dr Kevin Hainline, research professor at the ̽��ֱ�� of Arizona.

Fortunately, the galaxy happened to fall in a region where the team had conducted ultra-deep imaging with the JWST Mid-Infrared Instrument. ̽��ֱ��galaxy was bright enough to be detected in 7.7 micron light, with a higher intensity than extrapolation from lower wavelengths would predict.

“We are seeing extra emission from hydrogen and possibly even oxygen atoms, as is common in star-forming galaxies, but here shifted out to an unprecedented wavelength,” said Jakob Helton, graduate student at the ̽��ֱ�� of Arizona and lead author of a second paper on this finding.

These combined imaging results convinced the team to include the galaxy in what was planned to be the capstone observation of JADES, a 75-hour campaign to conduct spectroscopy on faint early galaxies. ̽��ֱ��spectroscopy confirmed their hopes that JADES-GS-z14-0 was indeed a record-breaking galaxy and that the fainter candidate, JADES-GS-z14-1, was nearly as far away.

Beyond the confirmation of distance, the spectroscopy allows further insight into the properties of the two galaxies. Being comparatively bright, JADES-GS-z14-0 will permit detailed study.

“We could have detected this galaxy even if it were 10 times fainter, which means that we could see other examples yet earlier in the Universe—probably into the first 200 million years,” says Brant Robertson, professor of astronomy and astrophysics at the ̽��ֱ�� of California-Santa Cruz, and lead author of a third paper on the team’s study of the evolution of this early population of galaxies. “ ̽��ֱ��early Universe has so much more to offer.”

Reference
Carniani, S et al. A shining cosmic dawn: spectroscopic confirmation of two luminous galaxies at z∼14. arXiv:2405.18485 [astro-ph.GA]

̽��ֱ��two earliest and most distant galaxies yet confirmed, dating back to only 300 million years after the Big Bang, have been discovered using NASA’s James Webb Space Telescope (JWST), an international team of astronomers today announced.

These galaxies join a small but growing population of galaxies from the first half billion years of cosmic history where we can really probe the stellar populations and the distinctive patterns of chemical elements within them

Francesco D’Eugenio

NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)

Infrared image showing JADES-GS-z14-0 galaxy

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Webb detects most distant black hole merger to date

sc604 — Thu, 16 May 2024 17:34:22 +0000

Astronomers have found supermassive black holes with masses of millions to billions times that of the Sun in most massive galaxies in the local Universe, including in our Milky Way galaxy. These black holes have likely had a major impact on the evolution of the galaxies they reside in. However, scientists still don’t fully understand how these objects grew to become so massive.

̽��ֱ��finding of gargantuan black holes already in place in the first billion years after the Big Bang indicates that such growth must have happened very rapidly, and very early. Now, the James Webb Space Telescope is shedding new light on the growth of black holes in the early Universe.

̽��ֱ��new Webb observations have provided evidence for an ongoing merger of two galaxies and their massive black holes when the Universe was just 740 million years old. ̽��ֱ��system is known as ZS7.

Massive black holes that are actively accreting matter have distinctive spectrographic features that allow astronomers to identify them. For very distant galaxies, like those in this study, these signatures are inaccessible from the ground and can only be seen with Webb.

“We found evidence for very dense gas with fast motions in the vicinity of the black hole, as well as hot and highly ionised gas illuminated by the energetic radiation typically produced by black holes in their accretion episodes,” said lead author Dr Hannah Übler of Cambridge’s Cavendish Laboratory and Kavli Institute for Cosmology. “Thanks to the unprecedented sharpness of its imaging capabilities, Webb also allowed our team to spatially separate the two black holes.”

̽��ֱ��team found that one of the two black holes has a mass that is 50 million times the mass of the Sun. “ ̽��ֱ��mass of the other black hole is likely similar, although it is much harder to measure because this second black hole is buried in dense gas,” said team member Professor Roberto Maiolino, also from the Kavli Institute.

“Our findings suggest that merging is an important route through which black holes can rapidly grow, even at cosmic dawn,” said Übler. “Together with other Webb findings of active, massive black holes in the distant Universe, our results also show that massive black holes have been shaping the evolution of galaxies from the very beginning.”

̽��ֱ��team notes that once the two black holes merge, they will also generate gravitational waves. Events like this will be detectable with the next generation of gravitational wave observatories, such as the upcoming Laser Interferometer Space Antenna (LISA) mission, which was recently approved by the European Space Agency and will be the first space-based observatory dedicated to studying gravitational waves.

This discovery was from observations made as part of the Galaxy Assembly with NIRSpec Integral Field Spectroscopy programme. ̽��ֱ��team has recently been awarded a new Large Programme in Webb’s Cycle 3 of observations, to study in detail the relationship between massive black holes and their host galaxies in the first billion years. An important component of this programme will be to systematically search for and characterise black hole mergers. This effort will determine the rate at which black hole merging occurs at early cosmic epochs and will assess the role of merging in the early growth of black holes and the rate at which gravitational waves are produced from the dawn of time.

These results have been published in the Monthly Notices of the Royal Astronomical Society.

Reference:
Hannah Übler et al. ‘GA-NIFS: JWST discovers an offset AGN 740 million years after the big bang’ Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae943

Adapted from a press release by the European Space Agency.

An international team of astronomers, led by the ̽��ֱ�� of Cambridge, has used the James Webb Space Telescope to find evidence for an ongoing merger of two galaxies and their massive black holes when the Universe was only 740 million years old. This marks the most distant detection of a black hole merger ever obtained and the first time that this phenomenon has been detected so early in the Universe.

Massive black holes have been shaping the evolution of galaxies from the very beginning

Hannah Übler

ESA/Webb, NASA, CSA, J. Dunlop, H. Übler, R. Maiolino, et. al

̽��ֱ��environment of the galaxy system ZS7 from the JWST PRIMER programme as seen by Webb's NIRCam instrument

Yes

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