Astronomy Cmarchesin: Big Bang

Showing posts with label Big Bang. Show all posts

Thursday, August 07, 2025

The Universe’s Secret Harvest: ALMA Sheds Light on “the Cosmic Grapes”

An artist’s impression of the “Cosmic Grapes” galaxy, composed of at least 15 massive star forming clumps—far more than current theoretical models predict could exist within a single rotating disk at this early time. Image credit NSF/AUI/NSF NRAO/B.Saxton.Credit: NSF/AUI/NSF NRAO/B. Saxton. Hi-Res File

The Cosmic Grapes initially appeared in past HST data as a typical galaxy with a smooth stellar disk (left). However, deep, high-resolution follow-up observations by JWST (middle) and ALMA (right) revealed that it actually consists of numerous compact stellar clumps embedded within a smooth, rotating gas disk. The red and blue colors in the right panel represent redshifted and blueshifted gas motions, respectively, tracing the rotation of the disk. Credit: NSF/AUI/NSF NRAO/B. Saxton. Hi-Res File

ALMA and JWST observations unveil unexpected details of rapid growth in a faint, newborn “grape-like” galaxy, similar to galaxies in the early universe following the Big Bang

Astronomers have discovered a remarkably clumpy rotating galaxy that existed just 900 million years after the Big Bang, shedding new light on how galaxies grew and evolved in the early universe. Nicknamed the “Cosmic Grapes,” the galaxy appears to be composed of at least 15 massive star-forming clumps—far more than current theoretical models predict could exist within a single rotating disk at this early time.

The discovery was made possible by an extraordinary combination of observations from the Atacama Large Millimeter/submillimeter Array (ALMA) and the James Webb Space Telescope (JWST), all focused on a single galaxy that happened to be perfectly magnified by a foreground galaxy cluster through gravitational lensing. In total, more than 100 hours of telescope time were dedicated to this single system, making it one of the most intensively studied galaxies from the early universe.

Although the galaxy had appeared as a smooth, single disk-like object in previous Hubble images, the powerful resolution of ALMA and JWST, enhanced by gravitational lensing, revealed a dramatically different picture: a rotating galaxy teeming with massive clumps, resembling a cluster of grapes. The finding marks the first time astronomers have linked small-scale internal structures and large-scale rotation in a typical galaxy at cosmic dawn, reaching spatial resolutions down to just 10 parsecs (about 30 light-years).

This galaxy does not represent a rare or extreme system. It lies squarely on the “main sequence” of galaxies in terms of its star forming activity, mass, size, chemical composition—meaning it is likely representative of a broader population. If so, many other seemingly smooth galaxies seen by current facilities may actually be made up of similar unseen substructures, hidden by the limits of current resolution.

Because existing simulations fail to reproduce such a large number of clumps in rotating galaxies at early times, this discovery raises key questions about how galaxies form and evolve. It suggests that our understanding of feedback processes and structure formation in young galaxies may need significant revision. The Cosmic Grapes now offer a unique window into the birth and growth of galaxies — and may be just the first of many. Future observations will be key to revealing whether such clumpy structures were common in the universe’s youth.

Source: National Radio Astronomy Observatory (NRAO)/News

About NRAO

The National Radio Astronomy Observatory (NRAO) is a facility of the U.S. National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

About ALMA

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Saturday, July 19, 2025

Chandra Joins In Discovery of Infinity Galaxy and Possible Newborn Black Hole

Infinity Galaxy
Credit: X-ray: NASA/CXC/Yale Univ./P. van Dokkum et al.;
Infrared: NASA/ESA/CSA/STScI/JWST;
Image Processing:NASA/CXC/SAO/N. Wolk; NASA/ESA/CSA/STScI/A. Pagan

JPEG (114.4 kb) - Large JPEG (2.4 MB) - Tiff (131.8 MB) - More Images

Scientists have discovered an oddly-shaped galaxy that may contain the first newborn supermassive black hole ever spotted, as described in our latest blog post. If confirmed, this result implies that black holes can form remarkably quickly, not just soon after the Big Bang but throughout cosmic time.

X-ray data from Chandra and radio data from the NSF’s Karl G. Jansky Very Large Array (VLA) have uncovered a growing supermassive black hole in this galaxy. Such black holes are usually found in the centers of massive galaxies, but the Chandra and VLA data may show that this is not the case for the Infinity Galaxy. The VLA data suggests the supermassive black hole is located in between both galaxies in a cloud of gas. The Chandra data unambiguously reveals the presence of a growing black hole near the center of the galaxy.

A paper that discusses the Webb, Chandra and VLA observations of the Infinity Galaxy has been accepted for publication in the Astrophysical Journal Letters and a preprint is here. The author list is Pieter van Dokkum (Yale), Gabriel Brammer (University of Copenhagen), and Josephine F.W. Baggen, Michael Keim, Priyamvada Natarajan and Imad Pasha (all from Yale). A separate paper led by van Dokkum with the newer Webb data is currently being reviewed at the Astrophysical Journal Letters and the submitted version is available online.

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory's C.handra X-ray C.enter controls science operations from Cambridge, Mass,brachusetts, and ,brflight operations from Burlington, Massachusetts.

Tour: NASA Telescopes Pinpoint Free-Roaming Massive Black Hole

Source: NASA’s Chandra X-ray Observatory

Visual Description:

A pair of distant galaxies that form the rough shape of an infinity symbol seen at about a 45-degree angle. Two overlapping, fuzzy rings with brighter blue patches are at the upper right and lower left. At the center of each ring is a bright yellow blob, which are the nuclei of each galaxy. These structures are seen in infrared data from the James Webb Space Telescope. Where the two rings overlap on the left side, there is a mottled green patch of glowing gas midway between the two yellow nuclei. It is offset slightly to the left. A cloud of purple passes between the two nuclei, extending over parts of each nuclei and toward the outer edges of the galaxies in both directions.This purple cloud shows X-rays seen with the Chandra X-ray Observatory

Fast Facts for Infinity Galaxy

Scale: Image is about 4 arcsec (110,000 light-years) across.
Category: Black Holes
Coordinates (J2000): RA 10h 00m 14.2s | Dec +02° 13´ 11.7"
Constellation: Sextans
Observation Dates: 6 observations from Dec 19, 2006 to Jan 4, 2007
Observation Time: 53 hours 58 minutes (2 days 5 hours 58 minutes)
Obs. ID: 8006 ,8007, 8012, 8013, 8497, 8503
Instrument: ACIS
References: van Dokkum, P. et al., 2025, ApJL, in press: DOI:10.48550/arXiv.2506.15618; van Dokkum, P. et al., 2025, ApJL, submitted: DOI:10.48550/arXiv.2506.15619;
Color Code: X-ray: purple; Infrared: red, green, blue
Distance Estimate: About 8.3 billion light-years (z=1.14)

Thursday, July 03, 2025

ALMA Reveals Hidden Structures in the First Galaxies of the Universe

A family portrait of galaxies from the CRISTAL survey. The image shows the gas traced by ALMA’s [CII] observations. Blue and green represent starlight captured by the Hubble and James Webb Space Telescopes. Credit: ALMA (ESO/NAOJ/NRAO) / HST / JWST / R. Herrera-Camus

A family portrait of galaxies from the CRISTAL survey. Red shows cold gas traced by ALMA’s [CII] observations. Blue and green represent starlight captured by the Hubble and James Webb Space Telescopes. Credit: ALMA (ESO/NAOJ/NRAO) / HST / JWST / R. Herrera-Camus

Zoom into the emission from an early galaxy observed in the CRISTAL survey. From left to right, the image shows stellar light captured by the James Webb and Hubble space telescopes, as well as the cold gas and rotation of the galaxy traced by ALMA through ionized carbon emission. Credit: ALMA / HST / JWST / R. Herrera-Camus

Artist’s illustration of CRISTAL-13. Dust-rich regions obscure newborn stars, whose energy is re-emitted at ALMA’s millimeter wavelengths. Right: young star clusters clear the dust and shine visibly in JWST and HST images. Credit: NSF/AUI/NRAO/B. Saxton

CRISTAL survey, led from Chile, traces cold gas, dust, and stellar light in 39 galaxies just 1 billion years after the Big Bang

Astronomers have used the Atacama Large Millimeter/submillimeter Array (ALMA) to peer into the early Universe and uncover the building blocks of galaxies during their formative years. The CRISTAL survey — short for [CII] Resolved ISM in STar-forming galaxies with ALMA — reveals cold gas, dust, and clumpy star formation in galaxies observed as they appeared just one billion years after the Big Bang.

“Thanks to ALMA’s unique sensitivity and resolution, we can resolve the internal structure of these early galaxies in ways never possible before,” said Rodrigo Herrera-Camus, principal investigator of the CRISTAL survey, professor at Universidad de Concepción, and Director of the Millennium Nucleus for Galaxy Formation (MINGAL) in Chile. “CRISTAL is showing us how the first galactic disks formed, how stars emerged in giant clumps, and how gas shaped the galaxies we see today.”

CRISTAL, an ALMA Large Program, observed 39 typical star-forming galaxies selected to represent the main population of galaxies in the early Universe. Using [CII] line emission, a specific type of light emitted by ionized carbon atoms in cold interstellar gas, as a tracer of cold gas and dust, and combining it with near-infrared images from the James Webb and Hubble Space Telescopes, researchers created a detailed map of the interstellar medium in each system. Among the key findings, most galaxies exhibited stellar birth in large clumps, each spanning several thousand light-years, revealing how star-forming regions assemble and evolve. A subset of galaxies showed signs of rotation, indicating the early formation of disk-like structures, which are precursors to modern spiral galaxies. The [CII] emission often extended far beyond the visible stars, indicating the presence of cold gas that may fuel future star formation or be expelled by stellar winds.

“What’s exciting about CRISTAL is that we are seeing early galaxies not just as points of light, but as complex ecosystems,” said Loreto Barcos-Muñoz, co-author of the study, astronomer at the U.S. National Radio Astronomy Observatory (NRAO), and ALMA point of contact for the survey. “This project shows how ALMA can resolve the internal structure of galaxies even in the distant Universe — revealing how they evolve, interact, and form stars.”

Two galaxies in the survey stood out. CRISTAL-13 features massive clouds of cosmic dust that block visible light from newborn stars. This light is reprocessed into millimeter wavelengths detectable by ALMA, revealing structures that are entirely hidden from telescopes observing in optical or infrared wavelengths. CRISTAL-10 presents a puzzling case: its ionized carbon emission is unusually faint relative to its infrared brightness, a trait only seen in rare, heavily obscured galaxies like Arp 220 in the nearby Universe. This suggests extreme physical conditions or an unusual power source in its interstellar medium.

“These observations highlight ALMA’s potential as a time machine, allowing us to peer into the early ages of the Universe,” said Sergio Martín, Head of the Department of Science Operations at ALMA. “Programs like CRISTAL demonstrate the power of ALMA’s Large Programs to drive high-impact science. They allow us to tackle the big questions of cosmic evolution with the unprecedented depth and resolution that only a world-class observatory like ALMA can provide.”

By conducting the first systematic survey of the cold gas in early galaxies and comparing it with their stars and dust, CRISTAL offers a new window into cosmic history. The survey sets the stage for future observations that may uncover how galaxies transition from turbulent early phases to the well-structured systems we see in the local Universe. “CRISTAL provides the kind of multi-wavelength data that allows us to test and refine our theories of galaxy evolution,” said Herrera-Camus. “This is a major step toward understanding how galaxies like our Milky Way came to be.

Scientific Paper

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Press Release

Additional Information

This research was published as "The ALMA-CRISTAL survey: Gas, dust, and stars in star-forming galaxies when the Universe was ∼1 Gyr old" by Herrera-Camus et al. in Astronomy & Astrophysics.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

Contacts:

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago - Chile
Phone: +56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Jill Malusky
Public Information Officer
NRAO
Phone: +1 304-456-2236

Email: jmalusky@nrao.edu

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: press@eso.org

Yuichi Matsuda
ALMA EA-ARC Staff Member
NAOJ
Email: yuichi.matsuda@nao.ac.jp

Saturday, April 19, 2025

NSF NOIRLab Astronomer Discovers Oldest Known Spiral Galaxy in the Universe

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Zhúlóng: The most distant spiral galaxy

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Zhúlóng: The most distant spiral galaxy

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Zhúlóng: The most distant spiral galaxy

The discovery tells astronomers that galaxies resembling the Milky Way can develop much earlier in the Universe than was previously thought possible

An international team led by NSF NOIRLab astronomer Christina Williams has discovered the most distant spiral galaxy known to date. Named Zhúlóng, meaning ‘Torch Dragon’ in Chinese mythology, this ultra-massive system existed just one billion years after the Big Bang, and yet it shows a surprisingly mature structure. Zhúlóng was discovered as part of the PANORAMIC Survey conducted on the James Webb Space Telescope.

Large, grand-design spiral galaxies like our own Milky Way are common in the nearby Universe. But they have proven hard to find in the early Universe, which is consistent with expectations that large disks with spiral arms should take many billions of years to form. However, assistant astronomer Christina Williams of NSF NOIRLab, which is funded by the U.S. National Science Foundation, has discovered a surprisingly mature spiral galaxy just one billion years after the Big Bang [1]. This is the most distant, earliest known spiral galaxy in the Universe.

This galaxy, named Zhúlóng — meaning ‘Torch Dragon’ in Chinese mythology, a creature associated with light and cosmic time — was discovered as part of the PANORAMIC Survey. This project is being conducted with the James Webb Space Telescope (JWST) and is co-led by Williams and Pascal Oesch of the University of Geneva (UNIGE).

The research was motivated by building a wide-area imaging survey using JWST to complement future wide-area surveys based out of NOIRLab, such as the upcoming Legacy Survey of Space and Time (LSST), which will be conducted using the NSF–DOE Vera C. Rubin Observatory.

“Wide-area surveys are necessary to discover rare, massive galaxies,” says Williams, co-author on the paper presenting these results. “We were hoping to discover massive and bright galaxies across the earliest epochs of the Universe to understand how massive galaxies form and evolve, which helps to interpret the later epochs of their evolution that will be observed with the LSST.”

Zhúlóng has a surprisingly mature structure that is unique among distant galaxies, which are typically clumpy and irregular. It resembles galaxies found in the nearby Universe and has a mass and size similar to those of the Milky Way. Its structure shows a compact bulge in the center with old stars, surrounded by a large disk of younger stars that concentrate in spiral arms.

This is a surprising discovery on several fronts. First, it shows that mature galaxies that resemble those in our neighborhood can develop much earlier in the Universe than was previously thought possible. Second, it has long been theorized that spiral arms in galaxies take many billions of years to form, but this galaxy demonstrates that spiral arms can also develop on shorter timescales. There is no other galaxy like Zhúlóng that astronomers know of during this early era of the Universe.

“It is really exciting that this galaxy resembles a grand-design spiral galaxy like our Milky Way,” says Williams. “It is generally thought that it takes billions of years for this structure to form in galaxies, but Zhúlóng shows that this could also happen in only one billion years.”

The rarity of galaxies like Zhúlóng suggests that spiral structures could be short-lived at this epoch of the Universe. It’s possible that galactic mergers, or other evolutionary processes that are more common in the early Universe, might destroy the spiral arms. Thus, spiral structures might be more stable later in cosmic time, which is why they are more common in our neighborhood.

The PANORAMIC survey is novel in that it is one of the first JWST projects to use “pure parallel mode” — an efficient observing strategy in which a second camera collects additional images while JWST’s main camera is pointed elsewhere. “It was definitely an adventure to be one of the first to use a new observing mode on a new telescope,” says Williams.

Future JWST and Atacama Large Millimeter/submillimeter Array (ALMA) observations will help confirm Zhúlóng’s properties and reveal more about its formation history. As new wide-area extragalactic surveys continue, astronomers expect to find more such galaxies, offering fresh insights into the complex processes shaping the early Universe.

Source: NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab)/News

Notes

[1] Zhúlóng was discovered at redshift 5.2, which equates to a light-travel time of about 12.5 billion years .

More information

This research was presented in a paper titled “PANORAMIC: Discovery of an Ultra-Massive Grand-Design Spiral Galaxy at z∼5.2” appearing in Astronomy & Astrophysics. DOI: 10.1051/0004-6361/202453487

The team is composed of Mengyuan Xiao (University of Geneva), Christina C. Williams (NSF NOIRLab, University of Arizona), Pascal A. Oesch (University of Geneva, University of Copenhagen), David Elbaz (Université Paris Cité), Miroslava Dessauges-Zavadsky (University of Geneva), Rui Marques-Chaves (University of Geneva), Longji Bing (University of Sussex), Zhiyuan Ji (University of Arizona), Andrea Weibel (University of Geneva), Rachel Bezanson (University of Pittsburgh), Gabriel Brammer (University of Copenhagen), Caitlin Casey (University of California, University of Texas at Austin, University of Copenhagen), Aidan P. Cloonan (University of Massachusetts Amherst), Emanuele Daddi (Université Paris Cité), Pratika Dayal (University of Groningen), Andreas L. Faisst (Caltech/IPAC), Marijn Franx (Leiden University), Karl Glazebrook (Swinburne University of Technology), Anne Hutter (University of Copenhagen), Jeyhan S. Kartaltepe (Rochester Institute of Technology), Ivo Labbe (Swinburne University of Technology), Guilaine Lagache (Aix-Marseille Université), Seunghwan Lim (University of Cambridge), Benjamin Magnelli (Université Paris Cité), Felix Martinez (Rochester Institute of Technology), Michael V. Maseda (University of Wisconsin-Madison), Themiya Nanayakkara (Swinburne University of Technology), Daniel Schaerer (University of Geneva), and Katherine E. Whitaker (University of Massachusetts Amherst).

NSF NOIRLab, the U.S. National Science Foundation center for ground-based optical-infrared astronomy, operates the International Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), NSF Kitt Peak National Observatory (KPNO), NSF Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and NSF–DOE Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona.

The scientific community is honored to have the opportunity to conduct astronomical research on I’oligam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence of I’oligam Du’ag to the Tohono O’odham Nation, and Maunakea to the Kanaka Maoli (Native Hawaiians) community.

Links

Contacts

Christina Williams
Assistant astronomer
NSF NOIRLab
Email: christina.williams@noirlab.edu

Josie Fenske
Jr. Public Information Officer
NSF NOIRLab
Email: josie.fenske@noirlab.edu

Baptiste Lavie
Public Outreach Officer
Department of Astronomy of the University of Geneva
Email: Baptiste.Lavie@unige.ch

Friday, April 04, 2025

Astronomers Find Giant Dinosaur of a Galaxy

This JWST image shows the Big Wheel galaxy (in the center) and its cosmic environment. The galaxy is a gigantic rotating disk lying 11.7 billion light-years away. Its spiral disk stretches across 100,000 light-years, making it larger than any other galaxy disk confirmed at this epoch of the universe. The blue blob and some of the other larger objects in the image are galaxies in the nearby universe. The smaller objects tend to be distant galaxies; however, the larger galaxy to the lower left of Big Wheel is part of the same remote galactic structure as Big Wheel. Credit: NASA/ESA

Newfound galaxy is one of the biggest ever found in distant universe

A team of astronomers has stumbled upon a humungous spiral galaxy, about five times more massive than our Milky Way galaxy and covering an area two times as big, making it among the largest known galaxies. The most surprising trait of the galaxy, however, is not its colossal size but the fact it existed in the early cosmos when the universe was only 2 billion years old.

"This galaxy is spectacular for being among the largest spiral galaxies ever found, which is unprecedented for this early era of the universe," says Charles (Chuck) Steidel (PhD '90), the Lee A. DuBridge Professor of Astronomy at Caltech. "Ultimately, this galaxy would have been stripped of gas and would not have survived to the modern day. It is like finding a live dinosaur, before it became extinct."

Steidel was part of an international team of astronomers, led by the University of Milano-Bicocca, that made the discovery and published its findings on March 17 in Nature Astronomy. The team's observations were made using James Webb Space Telescope (JWST), a partnership between NASA, the European Space Agency, and the Canadian Space Agency.

The researchers serendipitously noticed the large anomalous galaxy in JWST images taken of a nearby quasar—a powerful, active supermassive black hole. The team then followed up with JWST to learn more about the object's size, precise distance, rotation speed, and mass. Because the speed of light is finite, observations made of objects in the distant universe capture light from a bygone era. The JWST data revealed that the colossal specimen is not only surprisingly large, but also spins at great speeds. This led the team to nickname the galaxy "Big Wheel."

Prior to the discovery, it was thought that disk-shaped galaxies in the early universe were considerably smaller. (Disk galaxies include spiral galaxies as well as other flat, circular galaxies without spiral arms). Big Wheel is about three times larger than any previously discovered galaxies with similar masses at similar cosmic times, and it is also at least three times larger than what is predicted by current cosmological simulations. The galaxy's radius stretches across 100,00 light-years.

The finding begs the question: How did the galaxy get this big so fast? The team is not sure but suspects the answer has to do with the fact that it lives in a very dense area of space packed with a lot of young galaxies that will eventually coalesce into a giant cluster of gravitationally bound galaxies.

"Exceptionally dense environments such as the one hosting the Big Wheel are still a relatively unexplored territory," concludes co-author Sebastiano Cantalupo of the University of Milano-Bicocca. "Further targeted observations are needed to build a statistical sample of giant disks in the early universe and thus open a new window on the early stages of galaxy formation."

The Nature Astronomy study titled "A giant disk galaxy two billion years after the Big Bang," was funded by the European Research Council, the Fondazione Cariplo foundation, NASA, and the Australian Research Council.

Source: Caltech/News

Saturday, March 01, 2025

New discovery in the sky: Largest superstructure in the nearby universe unveiled

Distribution of galaxies (colour coding) and galaxy clusters (black dots) in a spherical shell with a distance of 416 to 826 million light years surrounding us. The five superstructures are marked: 1 Quipu, 2 Shapley, 3 Serpens-Corona Borealis and Hercules (overlapping in the sky), 4 Sculptor-Pegasus. The area enclosed by white lines is shadowed by the disk of the Milky Way. © MPE

A team of scientists has found the largest superstructure ever reliably characterised in the universe. The discovery was made while mapping the nearby universe using galaxy clusters detected by the ROSAT X-ray satellite's survey of the sky. With a length of about 1.4 billion lightyears, the new structure, which consists mainly of dark matter, is the largest known structure to date. Researchers at the Max Planck Institute for Extraterrestrial Physics (MPE) and the Max Planck Institute for Physics (MPP) led the study in collaboration with colleagues in Spain and South Africa.

Averaged over very large volumes, the universe appears almost homogeneous. On scales smaller than about a billion lightyears and in our cosmic neighbourhood, it is characterised by condensations of matter in superclusters and by voids. Precise knowledge of these structures is very important for cosmological research and the main motivation for mapping the nearby Universe.

“If you look at the distribution of the galaxy clusters in the sky in a spherical shell with a distance of 416 to 826 million light-years, you immediately notice a huge structure that stretches from high northern latitudes to almost the southern end of the sky,” explains Hans Böhringer, the project leader. It consists of 68 clusters of galaxies and has an estimated total mass of 2.4 1017 solar masses with a length of around 1.4 billion light years. This breaks the size record of all reliably measured cosmic structures. The largest of them so far, the “Sloan Great Wall”, for example, has a length of around 1.1 billion light years and it is located much further away.

An ATLAS of galaxy clusters

For their study, the scientists used an almost complete atlas of galaxy clusters in the nearby universe. “The catalogue was created with the help of the ROSAT X-ray satellite, built by MPE. In 1990, the satellite mapped the entire sky using a high-resolution X-ray telescope for the first time,” explains Joachim Trümper, the ROSAT project leader and emeritus Director of the MPE.

In the decades that followed, researchers worked to identify the galaxy clusters more precisely and to determine their distances. This resulted in a three-dimensional image of their distribution, in which the galaxy clusters precisely trace the structure of the large-scale distribution of matter in the universe, much like lighthouses trace a coastline. The catalogue covers the entire cosmic volume out to a distance of one billion light-years. In this region, the new structure appears much larger than all other structures.

Three-dimensional representation of the Quipu superstructure
© MPE

Importance for science: cosmography and cosmology

This finding is crucial for mapping the universe, but also for cosmological measurements. The researchers have shown how the presence of these structures affects the measurement of the Hubble constant or the microwave background. The cosmic background radiation was created shortly after the Big Bang and gives us important clues about the structure and evolution of the universe. The Hubble constant indicates the current expansion rate of the universe. “Even if these are only corrections of a few percent, they become increasingly important as the accuracy of cosmological observations increases,” emphasizes Gayoung Chon from the MPP.

The scientists have named their remarkable discovery “Quipu”, a term from the language of the Incas. The Incas used bundles of strings with knots for their bookkeeping and as letters. The superstructure resembles this ancient script, appearing as a long fibre with side strands woven into it. The scientists also chose the name because most of the distance measurements of the galaxy clusters were made at the European Southern Observatory (ESO) in Chile. The earthly quipus are on display at the Archaeological Museum in the capital Santiago de Chile - bringing us back to Earth from the far reaches of the cosmos.

Source: Max Planck Institute for Extraterrestrial Physics (MPE)/Press Releases

Contact:

Prof. Dr. Joachim Trümper
Direktor emeritus MPE
tel: +49 89 30000-3559
jtrumper@mpe.mpg.de
Max Planck Institute for Extraterrestrial Physics, Garching

Prof. Dr. Hans Böhringer
tel: +49 89 30000-3830
hxb@mpe.mpg.de
Max Planck Institute for Extraterrestrial Physics, Garching

Original publication

Hans Böhringer Gayoung Chon, Joachim Trümper, Renee C. Kraan-Korteweg, and Norbert Schartel
Unveiling the largest structures in the nearby Universe: Discovery of the Quipu superstructure

accepted for publication in Astronomy and Astrophysis

Source

Friday, February 14, 2025

Gemini North Teams Up With LOFAR to Reveal Largest Radio Jet Ever Seen in the Early Universe

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Artistic representation of the largest radio jet in the early Universe

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Quasar J1601+3102

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Quasar J1601+3102

Videos

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Cosmoview Episode 95: Gemini North Teams Up with LOFAR to Reveal the Largest Radio Jet Ever Seen in the Early Universe

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Cosmoview Episodio 95: Gemini Norte colabora con LOFAR para descubrir el Jet más grande del Universo temprano

The monster jet spans at least 200,000 light-years and formed when the Universe was less than 10% of its current age

Making use of the Gemini North telescope, one half of the International Gemini Observatory, funded in part by the U.S. National Science Foundation and operated by NSF NOIRLab, astronomers have characterized the largest-ever early-Universe radio jet. Historically, such large radio jets have remained elusive in the distant Universe. With these observations, astronomers have valuable new insights into when the first jets formed in the Universe and how they impacted the evolution of galaxies.

From decades of astronomical observations scientists know that most galaxies contain massive black holes at their centers. The gas and dust falling into these black holes liberates an enormous amount of energy as a result of friction, forming luminous galactic cores, called quasars, that expel jets of energetic matter. These jets can be detected with radio telescopes up to large distances. In our local Universe these radio jets are not uncommon, with a small fraction being found in nearby galaxies, but they have remained elusive in the distant, early Universe until now.

Using a combination of telescopes, astronomers have discovered a distant, two-lobed radio jet that spans an astonishing 200,000 light-years at least — twice the width of the Milky Way. This is the largest radio jet ever found this early in the history of the Universe [1]. The jet was first identified using the international Low Frequency Array (LOFAR) Telescope, a network of radio telescopes throughout Europe.

Follow-up observations in the near-infrared with the Gemini Near-Infrared Spectrograph (GNIRS), and in the optical with the Hobby Eberly Telescope, were obtained to paint a complete picture of the radio jet and the quasar producing it. These findings are crucial to gaining more insight into the timing and mechanisms behind the formation of the first large-scale jets in our Universe.

GNIRS is mounted on the Gemini North telescope, one half of the International Gemini Observatory, funded in part by the U.S. National Science Foundation (NSF) and operated by NSF NOIRlab.

“We were searching for quasars with strong radio jets in the early Universe, which helps us understand how and when the first jets are formed and how they impact the evolution of galaxies,” says Anniek Gloudemans, postdoctoral research fellow at NOIRLab and lead author of the paper presenting these results in The Astrophysical Journal Letters.

Determining the properties of the quasar, such as its mass and the rate at which it is consuming matter, is necessary for understanding its formation history. To measure these parameters the team looked for a specific wavelength of light emitted by quasars known as the MgII (magnesium) broad emission line. Normally, this signal appears in the ultraviolet wavelength range. However, owing to the expansion of the Universe, which causes the light emitted by the quasar to be ‘stretched’ to longer wavelengths, the magnesium signal arrives at Earth in the near-infrared wavelength range, where it is detectable with GNIRS.

The quasar, named J1601+3102, formed when the Universe was less than 1.2 billion years old — just 9% of its current age. While quasars can have masses billions of times greater than that of our Sun, this one is on the small side, weighing in at 450 million times the mass of the Sun. The double-sided jets are asymmetrical both in brightness and the distance they stretch from the quasar, indicating an extreme environment may be affecting them.

“Interestingly, the quasar powering this massive radio jet does not have an extreme black hole mass compared to other quasars,” says Gloudemans. “This seems to indicate that you don’t necessarily need an exceptionally massive black hole or accretion rate to generate such powerful jets in the early Universe.”

The previous dearth of large radio jets in the early Universe has been attributed to noise from the cosmic microwave background — the ever-present fog of microwave radiation left over from the Big Bang. This persistent background radiation normally diminishes the radio light of such distant objects.

“It’s only because this object is so extreme that we can observe it from Earth, even though it’s really far away,” says Gloudemans. “This object shows what we can discover by combining the power of multiple telescopes that operate at different wavelengths.”

“When we started looking at this object we were expecting the southern jet to just be an unrelated nearby source, and for most of it to be small. That made it quite surprising when the LOFAR image revealed large, detailed radio structures,” says Frits Sweijen, postdoctoral research associate at Durham University and co-author of the paper. “The nature of this distant source makes it difficult to detect at higher radio frequencies, demonstrating the power of LOFAR on its own and its synergies with other instruments.”

Scientists still have a multitude of questions about how radio-bright quasars like J1601+3102 differ from other quasars. It remains unclear what circumstances are necessary to create such powerful radio jets, or when the first radio jets in the Universe formed. Thanks to the collaborative power of Gemini North, LOFAR and the Hobby Eberly Telescope, we are one step closer to understanding the enigmatic early Universe.

Source: NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab)/News

Notes

[1] An example of a monster radio jet found in the nearby Universe is the 23 million-light-year-long jet, named Porphyrion, which was observed 6.3 billion years after the Big Bang.

More information

This research was presented in a paper titled “Monster radio jet (>66 kpc) observed in quasar at z ∼ 5” to appear in The Astrophysical Journal Letters. DOI: 10.3847/2041-8213/ad9609

The team is composed of Anniek J. Gloudemans (NSF NOIRLab, International Gemini Observatory), Frits Sweijen (Durham University), Leah K. Morabito (Durham University), Emanuele Paolo Farina (NSF NOIRLab, International Gemini Observatory), Kenneth J. Duncan (Royal Observatory, Edinburgh), Yuichi Harikane (University of Tokyo), Huub J. A. Röttgering (Leiden University), Aayush Saxena (University of Oxford, Durham University), and Jan-Torge Schindler (University of Hamburg).

NSF NOIRLab, the U.S. National Science Foundation center for ground-based optical-infrared astronomy, operates the International Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), NSF Kitt Peak National Observatory (KPNO), NSF Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and NSF–DOE Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona.

The scientific community is honored to have the opportunity to conduct astronomical research on I’oligam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence of I’oligam Du’ag to the Tohono O’odham Nation, and Maunakea to the Kanaka Maoli (Native Hawaiians) community.

Links

Contacts:

Anniek Gloudemans
Postdoctoral research fellow
NSF NOIRLab / International Gemini Observatory
Email: anniek.gloudemans@noirlab.edu

Frits Sweijen
Postdoctoral research associate
Durham University
Email: frits.sweijen@durham.ac.uk

Josie Fenske
Jr. Public Information Officer
NSF NOIRLab
Email: josie.fenske@noirlab.edu

Thursday, January 30, 2025

Extreme Variability at the Edge of the Universe

An artist’s illustration of a close-up view of a black hole and its jet, like the one in CFHQS J1429+5447. Image credit: NASA/CXC/M. Weiss (CXC). Download Image

Black holes are the most powerful and scary monsters in our universe, lurking at the centers of galaxies. Some, such as the black hole at the center of our own Milky Way Galaxy, have already finished their cosmic meals, with just occasional nibbles observed today. Others, however, are seen ravenously devouring delicious matter from their surroundings. At such times, black holes are noisy eaters, dominating all the activity in their host galaxy centers. As matter spirals in towards the bottomless maw, it collides, heats up, and becomes very bright from X-ray to infrared energies. The accretion disk around a supermassive black hole can easily outshine the billions of stars in a galaxy, and that incredible brightness can make them some of the most distant objects we can observe in both space and time. Black holes can also be messy eaters, spewing out material in cosmic jets that can reach thousands and even millions of light years from the black hole—material that can then go on to influence the universe around it.

Of the many mysteries that keep astronomers up all night observing and pondering these enigmatic beasts, one of the most perplexing is how black holes grow to such enormous sizes. We see supermassive black holes with masses hundreds of millions of times that of the Sun, observed when the universe was only a few hundred million years old. It’s like finding 7-foot basketball players or 300-pound football players with appetites to match in a Kindergarten classroom: just how were they able to grow so big so quickly?

Recent observations by NASA’s NuSTAR and Chandra X-ray observatories might offer some clues. In a paper recently published by the Astrophysical Journal, scientists led by Lea Marcotulli at Yale University and Thomas Connor at the Center for Astrophysics | Harvard & Smithsonian report on observations of the most X-ray luminous accreting black hole, or quasar, ever discovered in the first billion years of the universe. This quasar, called CFHQS J1429+5447, was initially found 15 years ago using data from a ground-based telescope that surveyed wide patches of the sky. Far more recently it was observed by Chandra, which was able to pick up X-rays from this incredibly distant source. Only four months afterwards, NuSTAR also observed it, finding that the quasar had doubled in X-ray brightness in that time.

Such a dramatic variation in such a short time for something this massive is evidence towards this quasar being a particularly messy eater, expelling a powerful jet of material at close to the speed of light. This jet is pointed straight at Earth—a chance alignment that boosts the amount of light making its way to us, allowing telescopes in Earth's orbit like NuSTAR and Chandra to see it at such a great distance.

"These results have significant implications for supermassive black holes and jet evolution theories," said Marcotulli. "The presence of a jet may be a necessity to grow such extreme black holes so early in the Universe."

Because the light observed from this quasar was emitted when the Universe was still very young, this lets us see into an era soon after the Big Bang called the Epoch of Reionization. This time period was when light began to be able to pass through the Universe unimpeded, which is what allows us to see stars and galaxies and distant quasars today. Exactly what kind of objects helped to clear the way for light to travel through space is a mystery that astronomers are still seeking to unravel, but the discovery of a cosmic jet like this one suggests that the Universe's biggest, messiest eaters might have been involved.

Source: NASA's Nuclear Spectroscopic Telescope Array (NuSTAR)/News

Friday, January 17, 2025

Newfound Galaxy Class May Indicate Early Black Hole Growth, Webb Finds

Little Red Dots (NIRCam Image)
Credits/Image: NASA, ESA, CSA, STScI, Dale Kocevski (Colby College)

In December 2022, less than six months after commencing science operations, NASA’s James Webb Space Telescope revealed something never seen before: numerous red objects that appear small on the sky, which scientists soon called “little red dots” (LRDs). Though these dots are quite abundant, researchers are perplexed by their nature, the reason for their unique colors, and what they convey about the early universe.

A team of astronomers recently compiled one of the largest samples of LRDs to date, nearly all of which existed during the first 1.5 billion years after the big bang. They found that a large fraction of the LRDs in their sample showed signs of containing growing supermassive black holes.

“We’re confounded by this new population of objects that Webb has found. We don’t see analogs of them at lower redshifts, which is why we haven’t seen them prior to Webb,” said Dale Kocevski of Colby College in Waterville, Maine, and lead author of the study. “There's a substantial amount of work being done to try to determine the nature of these little red dots and whether their light is dominated by accreting black holes.”

A Potential Peek Into Early Black Hole Growth

A significant contributing factor to the team’s large sample size of LRDs was their use of publicly available Webb data. To start, the team searched for these red sources in the Cosmic Evolution Early Release Science (CEERS) survey before widening their scope to other extragalactic legacy fields, including the JWST Advanced Deep Extragalactic Survey (JADES) and the Next Generation Deep Extragalactic Exploratory Public (NGDEEP) survey.

The methodology used to identify these objects also differed from previous studies, resulting in the census spanning a wide redshift range. The distribution they discovered is intriguing: LRDs emerge in large numbers around 600 million years after the big bang and undergo a rapid decline in quantity around 1.5 billion years after the big bang.

The team looked toward the Red Unknowns: Bright Infrared Extragalactic Survey (RUBIES) for spectroscopic data on some of the LRDs in their sample. They found that about 70 percent of the targets showed evidence for gas rapidly orbiting 2 million miles per hour (1,000 kilometers per second) – a sign of an accretion disk around a supermassive black hole. This suggests that many LRDs are accreting black holes, also known as active galactic nuclei (AGN).

“The most exciting thing for me is the redshift distributions. These really red, high-redshift sources basically stop existing at a certain point after the big bang,” said Steven Finkelstein, a co-author of the study at the University of Texas at Austin. “If they are growing black holes, and we think at least 70 percent of them are, this hints at an era of obscured black hole growth in the early universe.”

Contrary to Headlines, Cosmology Isn’t Broken

When LRDs were first discovered, some suggested that cosmology was “broken.” If all of the light coming from these objects was from stars, it implied that some galaxies had grown so big, so fast, that theories could not account for them.

The team’s research supports the argument that much of the light coming from these objects is from accreting black holes and not from stars. Fewer stars means smaller, more lightweight galaxies that can be understood by existing theories.

“This is how you solve the universe-breaking problem,” said Anthony Taylor, a co-author of the study at the University of Texas at Austin.

Curiouser and Curiouser

There is still a lot up for debate as LRDs seem to evoke even more questions. For example, it is still an open question as to why LRDs do not appear at lower redshifts. One possible answer is inside-out growth: As star formation within a galaxy expands outward from the nucleus, less gas is being deposited by supernovas near the accreting black hole, and it becomes less obscured. In this case, the black hole sheds its gas cocoon, becomes bluer and less red, and loses its LRD status.

Additionally, LRDs are not bright in X-ray light, which contrasts with most black holes at lower redshifts. However, astronomers know that at certain gas densities, X-ray photons can become trapped, reducing the amount of X-ray emission. Therefore, this quality of LRDs could support the theory that these are heavily obscured black holes.

The team is taking multiple approaches to understand the nature of LRDs, including examining the mid-infrared properties of their sample, and looking broadly for accreting black holes to see how many fit LRD criteria. Obtaining deeper spectroscopy and select follow-up observations will also be beneficial for solving this currently “open case” about LRDs.

“There’s always two or more potential ways to explain the confounding properties of little red dots,” said Kocevski. “It’s a continuous exchange between models and observations, finding a balance between what aligns well between the two and what conflicts.”

These results were presented in a press conference at the 245th meeting of the American Astronomical Society in National Harbor, Maryland, and have been accepted for publication in The Astrophysical Journal.

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).

Source: NASA's James Webb Space Telescope/News

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Abigail Major
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Science: Dale Kocevski (Colby College)

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Contact Us: Direct inquiries to the News Team.

Wednesday, October 23, 2024

Astronomers detect ancient lonely quasars with murky origins

This image, taken by NASA’s James Webb Space Telescope, shows an ancient quasar (circled in red) with fewer than expected neighboring galaxies (bright blobs), challenging physicists’ understanding of how the first quasars and supermassive black holes formed. Credit: Christina Eilers/EIGER team

The quasars appear to have few cosmic neighbors, raising questions about how they first emerged more than 13 billion years ago

A quasar is the extremely bright core of a galaxy that hosts an active supermassive black hole at its center. As the black hole draws in surrounding gas and dust, it blasts out an enormous amount of energy, making quasars some of the brightest objects in the universe. Quasars have been observed as early as a few hundred million years after the Big Bang, and it’s been a mystery as to how these objects could have grown so bright and massive in such a short amount of cosmic time..

Scientists have proposed that the earliest quasars sprang from overly dense regions of primordial matter, which would also have produced many smaller galaxies in the quasars’ environment. But in a new MIT-led study, astronomers observed some ancient quasars that appear to be surprisingly alone in the early universe.

The astronomers used NASA’s James Webb Space Telescope (JWST) to peer back in time, more than 13 billion years, to study the cosmic surroundings of five known ancient quasars. They found a surprising variety in their neighborhoods, or “quasar fields.” While some quasars reside in very crowded fields with more than 50 neighboring galaxies, as all models predict, the remaining quasars appear to drift in voids, with only a few stray galaxies in their vicinity.

These lonely quasars are challenging physicists’ understanding of how such luminous objects could have formed so early on in the universe, without a significant source of surrounding matter to fuel their black hole growth.

“Contrary to previous belief, we find on average, these quasars are not necessarily in those highest-density regions of the early universe. Some of them seem to be sitting in the middle of nowhere,” says Anna-Christina Eilers, assistant professor of physics at MIT. “It’s difficult to explain how these quasars could have grown so big if they appear to have nothing to feed from.”

There is a possibility that these quasars may not be as solitary as they appear, but are instead surrounded by galaxies that are heavily shrouded in dust and therefore hidden from view. Eilers and her colleagues hope to tune their observations to try and see through any such cosmic dust, in order to understand how quasars grew so big, so fast, in the early universe.

Eilers and her colleagues report their findings in a paper appearing today in the Astrophysical Journal. The MIT co-authors include postdocs Rohan Naidu and Minghao Yue; Robert Simcoe, the Francis Friedman Professor of Physics and director of MIT’s Kavli Institute for Astrophysics and Space Research; and collaborators from institutions including Leiden University, the University of California at Santa Barbara, ETH Zurich, and elsewhere.

Galactic neighbors

The five newly observed quasars are among the oldest quasars observed to date. More than 13 billion years old, the objects are thought to have formed between 600 to 700 million years after the Big Bang. The supermassive black holes powering the quasars are a billion times more massive than the sun, and more than a trillion times brighter. Due to their extreme luminosity, the light from each quasar is able to travel over the age of the universe, far enough to reach JWST’s highly sensitive detectors today.

“It’s just phenomenal that we now have a telescope that can capture light from 13 billion years ago in so much detail,” Eilers says. “For the first time, JWST enabled us to look at the environment of these quasars, where they grew up, and what their neighborhood was like.”

The team analyzed images of the five ancient quasars taken by JWST between August 2022 and June 2023. The observations of each quasar comprised multiple “mosaic” images, or partial views of the quasar’s field, which the team effectively stitched together to produce a complete picture of each quasar’s surrounding neighborhood.

The telescope also took measurements of light in multiple wavelengths across each quasar’s field, which the team then processed to determine whether a given object in the field was light from a neighboring galaxy, and how far a galaxy is from the much more luminous central quasar.

“We found that the only difference between these five quasars is that their environments look so different,” Eilers says. “For instance, one quasar has almost 50 galaxies around it, while another has just two. And both quasars are within the same size, volume, brightness, and time of the universe. That was really surprising to see.”

Growth spurts

The disparity in quasar fields introduces a kink in the standard picture of black hole growth and galaxy formation. According to physicists’ best understanding of how the first objects in the universe emerged, a cosmic web of dark matter should have set the course. Dark matter is an as-yet unknown form of matter that has no other interactions with its surroundings other than through gravity.

Shortly after the Big Bang, the early universe is thought to have formed filaments of dark matter that acted as a sort of gravitational road, attracting gas and dust along its tendrils. In overly dense regions of this web, matter would have accumulated to form more massive objects. And the brightest, most massive early objects, such as quasars, would have formed in the web’s highest-density regions, which would have also churned out many more, smaller galaxies.

“The cosmic web of dark matter is a solid prediction of our cosmological model of the Universe, and it can be described in detail using numerical simulations,” says co-author Elia Pizzati, a graduate student at Leiden University. “By comparing our observations to these simulations, we can determine where in the cosmic web quasars are located.”

Scientists estimate that quasars would have had to grow continuously with very high accretion rates in order to reach the extreme mass and luminosities at the times that astronomers have observed them, fewer than 1 billion years after the Big Bang.

“The main question we’re trying to answer is, how do these billion-solar-mass black holes form at a time when the universe is still really, really young? It’s still in its infancy,” Eilers says.

The team’s findings may raise more questions than answers. The “lonely” quasars appear to live in relatively empty regions of space. If physicists’ cosmological models are correct, these barren regions signify very little dark matter, or starting material for brewing up stars and galaxies. How, then, did extremely bright and massive quasars come to be?

“Our results show that there’s still a significant piece of the puzzle missing of how these supermassive black holes grow,” Eilers says. “If there’s not enough material around for some quasars to be able to grow continuously, that means there must be some other way that they can grow, that we have yet to figure out.”

This research was supported, in part, by the European Research Council.

By Jennifer Chu | MIT News

Source: Massachusetts Institute of Technology (MIT)

Sunday, September 29, 2024

In Odd Galaxy, NASA's Webb Finds Potential Missing Link to First Stars

Galaxy GS-NDG-9422 (NIRCam Image)

Caption: The galaxy GS-NDG-9422 may easily have gone unnoticed. However, what appears as a faint blur in this James Webb Space Telescope NIRCam (Near-Infrared Camera) image may actually be a groundbreaking discovery that points astronomers on a new path of understanding galaxy evolution in the early universe.

Detailed information on the galaxy’s chemical makeup, captured by Webb’s NIRSpec (Near-Infrared Spectrograph) instrument, indicates that the light we see in this image is coming from the galaxy’s hot gas, rather than its stars. That is the best explanation astronomers have discovered so far to explain the unexpected features in the light spectrum. They think that the galaxy’s stars are so extremely hot (more than 140,000 degrees Fahrenheit, or 80,000 degrees Celsius) that they are heating up the nebular gas, allowing it to shine even brighter than the stars themselves.

The authors of a new study on Webb’s observations of the galaxy think GS-NDG-9422 may represent a never-before-seen phase of galaxy evolution in the early universe, within the first billion years after the big bang. Their task now is to see if they can find more galaxies displaying the same features. Credits: Image: NASA, ESA, CSA, STScI, Alex Cameron (Oxford)

Looking deep into the early universe with NASA’s James Webb Space Telescope, astronomers have found something unprecedented: a galaxy with an odd light signature, which they attribute to its gas outshining its stars. Found approximately one billion years after the big bang, galaxy GS-NDG-9422 (9422) may be a missing-link phase of galactic evolution between the universe’s first stars and familiar, well-established galaxies.

“My first thought in looking at the galaxy’s spectrum was, ‘that’s weird,’ which is exactly what the Webb telescope was designed to reveal: totally new phenomena in the early universe that will help us understand how the cosmic story began,” said lead researcher Alex Cameron of the University of Oxford.

Cameron reached out to colleague Harley Katz, a theorist, to discuss the strange data. Working together, their team found that computer models of cosmic gas clouds heated by very hot, massive stars, to an extent that the gas shone brighter than the stars, was nearly a perfect match to Webb’s observations.

“It looks like these stars must be much hotter and more massive than what we see in the local universe, which makes sense because the early universe was a very different environment,” said Katz, of Oxford and the University of Chicago.

In the local universe, typical hot, massive stars have a temperature ranging between 70,000 to 90,000 degrees Fahrenheit (40,000 to 50,000 degrees Celsius). According to the team, galaxy 9422 has stars hotter than 140,000 degrees Fahrenheit (80,000 degrees Celsius).

The research team suspects that the galaxy is in the midst of a brief phase of intense star formation inside a cloud of dense gas that is producing a large number of massive, hot stars. The gas cloud is being hit with so many photons of light from the stars that it is shining extremely brightly.

In addition to its novelty, nebular gas outshining stars is intriguing because it is something predicted in the environments of the universe’s first generation of stars, which astronomers classify as Population III stars.

“We know that this galaxy does not have Population III stars, because the Webb data shows too much chemical complexity. However, its stars are different than what we are familiar with – the exotic stars in this galaxy could be a guide for understanding how galaxies transitioned from primordial stars to the types of galaxies we already know,” said Katz. At this point, galaxy 9422 is one example of this phase of galaxy development, so there are still many questions to be answered. Are these conditions common in galaxies at this time period, or a rare occurrence? What more can they tell us about even earlier phases of galaxy evolution? Cameron, Katz, and their research colleagues are actively identifying more galaxies to add to this population to better understand what was happening in the universe within the first billion years after the big bang.

“It’s a very exciting time, to be able to use the Webb telescope to explore this time in the universe that was once inaccessible,” Cameron said. “We are just at the beginning of new discoveries and understanding.”

The research paper is published in Monthly Notices of the Royal Astronomical Society.

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).