Tag Archives: ALMA

ALMA Achieves Best-Ever Image of Exoplanet Debris Disk

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Using the Atacama Large Millimeter/Submillimeter Array (ALMA), astronomers have unveiled stunning high-resolution images of 24 debris disks—dusty remnants that form after planetary systems complete their formation—showcasing the intricate transitional stages between the birth of planets and fully developed exoplanetary systems.

The ARKS gallery of faint debris disks reveals intricate shapes, including belts with multiple rings and sharp edges. Amber highlights the abundance of dust, while blue indicates carbon monoxide in gas-rich disks. Image credit: Sebastian Marino / Sorcha Mac Manamon / ARKS collaboration.

Young and mature planetary systems feature faint dust belts known as debris disks.

These disks are believed to result from collisions between large planetesimals, given dust’s brief lifespan against radiation and collisions.

Debris disks serve as the extrasolar equivalents of asteroids and the Kuiper Belt in our solar system.

With ages spanning from tens of millions to thousands of years, they offer a unique view into the final assembly of planetary systems.

Furthermore, they enable us to draw connections between protoplanetary disk structures and known mature exoplanetary populations.

Debris disks are significantly darker, appearing hundreds or thousands of times fainter than the luminous, gas-rich disks where planets are born.

Meredith Hughes, an astronomer at Wesleyan University, and her team have surmounted these challenges to produce the most detailed images to date of these disks.

Utilizing ALMA, they captured high-resolution images of 24 debris disks surrounding other stars.

This observation contributes to the ALMA survey aimed at resolving the Outer Kuiper Belt Substructure (ARKS).

“While we’ve often glimpsed ‘baby pictures’ of planet formation, the ‘teenage’ phase has remained elusive,” says Hughes.

Dr. Sebastian Marino, an astronomer at the University of Exeter, noted: “We’re observing genuine diversity—not just simple rings, but multi-ring belts and pronounced asymmetries, illustrating a dynamic and tumultuous phase in planetary history.”

ARKS stands as the largest and highest resolution survey of debris disks, akin to DSHARP, setting a new gold standard in the field.

Approximately one-third of the studied disks display distinct substructures, such as multiple rings and noticeable gaps, suggesting features left over from early planetary formation or shaped by planets over extended timescales.

Some disks retain the complex structure from earlier stages, while others have deteriorated into broad, smooth bands akin to the expected development of our solar system.

Many disks exhibit zones of tranquility and chaos, with vertically raised areas resembling unique objects in our solar system, blending classical Kuiper Belt objects with those disturbed by Neptune’s past migrations.

Some disks maintain gas longer than anticipated. In certain star systems, residual gas can influence the chemistry of developing planets or encourage dust to form extensive halos.

Numerous disks feature bright arcs or eccentric configurations, indicating gravitational effects from unseen exoplanets, scars left by planetary migration, or interactions between gas and dust.

Dr. Luca Matra, an astronomer at Trinity College, Dublin, remarked: “These disks encapsulate a period when planetary orbits were disrupted, akin to the massive impacts that shaped our early solar system.”

“By examining dozens of disks around stars of varying ages and types, ARKS aims to determine if their chaotic features are inherited, influenced by planets, or derived from other cosmic forces.”

“Understanding these nuances may shed light on whether our solar system’s history is unique or part of a common pattern.”

For more on this result, see the latest issue of Astronomy and Astrophysics.

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S. Marino et al. 2026. ALMA surveys to resolve the ExoKuiper belt substructure (ARKS). I. Motivation, sample, data reduction, and results overview. A&A 705, A195; doi: 10.1051/0004-6361/202556489

Source: www.sci.news

ALMA Discovers Superheated Gas in Distant Galaxy Protocluster

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Revolutionary findings from the Atacama Large Millimeter/Submillimeter Array (ALMA) have uncovered scorching intracluster gas in the young galaxy cluster SPT2349-56, just 1.4 billion years post-Big Bang. This groundbreaking discovery challenges existing models of galaxy cluster evolution.

Artist’s impression of the forming galaxy cluster SPT2349-56, showcasing radio jets from active galaxies within a hot intracluster atmosphere. Image credit: Lingxiao Yuan.

The SPT2349-56 galaxy cluster is located approximately 12.4 billion light-years away, providing a glimpse into the universe when it was only 1.4 billion years old, or about ten percent of its current age.

This compact protocluster hosts multiple actively growing supermassive black holes and over 30 starburst galaxies.

These starburst galaxies are forming stars at a staggering rate—1,000 times faster than the Milky Way—and are densely packed within a space only three times larger than the Milky Way itself.

“We were not prepared to discover such a hot stellar atmosphere at this early stage in the universe’s history,” remarked Dazhi Zhou, a Ph.D. candidate at the University of British Columbia.

Astronomers utilized a unique observation methodology known as thermal observation, particularly employing the Sunyaev Zeldovich (tSZ) Effect.

This approach identifies faint shadows cast by hot electrons in galaxy clusters against the faint cosmic microwave background, rather than the light emitted directly by the gas.

Previously, astronomers believed that galaxy clusters lacked the maturity required for their gas to heat up and evolve during the early cosmic era.

The discovery of hot cluster atmospheres had never been recorded within the initial 3 billion years following the Big Bang.

“SPT2349-56 reshapes our understanding,” stated Professor Scott Chapman, a researcher at Dalhousie University and the University of British Columbia.

“Our findings indicate that the cluster’s atmosphere is superheating remarkably early—just 1.4 billion years after the Big Bang—during a period when we anticipated the gas to be cooler and accumulating slowly.”

“This raises the possibility that the formation of large clusters could heat their gas much more efficiently and intensely than our current models suggest.”

The intense explosion from SPT2349-56’s supermassive black hole, identified as a bright radio galaxy, may be an efficient mechanism for superheating the surrounding gas, according to the study.

This discovery implies that energetic phenomena, such as outbursts from supermassive black holes or violent starbursts, might have played significant roles in rapidly heating the gas in early galaxy clusters within the first billion years of the universe.

This superheating may be crucial for transforming these young, cold galaxy clusters into the vast, hot galaxy clusters observed today.

Current models may require reassessment regarding our understanding of how galaxies and their environments evolve.

This finding marks the earliest direct detection of hot cluster gases, pushing the boundaries of astronomical research into these environments.

The identification of a significant reservoir of hot plasma at such an early cosmic epoch forces scientists to reconsider the sequence and pace of galaxy cluster evolution.

It also generates new inquiries about the interplay between supermassive black holes and galaxy formation in shaping the universe.

“SPT2349-56 serves as an intriguing laboratory,” Zhou commented.

“We are witnessing intense star formation, energetic supermassive black holes, and this superheated atmosphere all confined within young, dense star clusters.”

“There remains a considerable observational gap between this chaotic initial phase and the more tranquil clusters observed later in cosmic history.”

“Mapping the evolution of the universe’s atmosphere over time will be a compelling avenue for future exploration.”

For further reading, see the published results in the journal Nature dated January 5, 2026.

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Zhou D. et al. Detection of hot intracluster gas at redshift 4.3 via Sunyaev Zeldovich. Nature, published online January 5, 2026. doi: 10.1038/s41586-025-09901-3

Source: www.sci.news

ALMA Observes Spiral Gas Streamers Controlled by Magnetic Fields in Star-Forming Areas

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This stream of gas transports material from the clouds surrounding the star-forming area within Perseus directly into an emerging binary star system known as SVS 13A.

Artist’s impression of the SVS 13A system. Image credit: NSF/AUI/NSF’s NRAO/P.Vosteen.

Stars are formed from clouds of gas and dust, and recent observations indicate that the process of star formation is far more dynamic than previously understood.

New findings from the Atacama Large Millimeter/Submillimeter Array (ALMA) reveal both dust and molecules swirling around the SVS 13A system. This data shows how the magnetic field not only permeates these stellar nurseries but actively directs the flow of matter, offering a preferred path for gas to accumulate in the disk where new stars and planets arise.

“Visualize a garden hose, but instead of water, it smoothly channels materials for star formation through intricate pathways carved by unseen forces,” explains Dr. Paulo Cortes, an astronomer at the NSF National Radio Astronomy Observatory and the joint ALMA telescope.

“This perspective from ALMA observations presents channels of gas known as subalfvénic streamers, regulated by spiral magnetic field lines.”

“This new data provides an insightful glimpse into the star formation process.”

“These streamers illustrate how magnetic fields can influence star formation by managing material influx, akin to a private highway facilitating car travel.”

ALMA’s images and findings uncover two spiral arms of dust encircling the star, with gas streams closely mirroring the same trajectory.

This remarkable configuration implies that the gas within the streamer is traversing at a slower pace than previously believed, reinforcing the concept of a magnetized channel rather than a chaotic, collapsing cloud.

The presence of such streamers, linking clouds to disks and supplying them with material in a managed fashion, indicates that both gravity and magnetism are crucial in the formation of stars and the shaping of potential planetary bodies around them.

This groundbreaking result signifies the first instance where astronomers have directly mapped both a streamer and its associated magnetic field in a single observation.

“Subalfvenic streamers indicate a fresh role for magnetic fields amidst gravitational dominance, acting as ‘guides’ to assist the descent of material from the outer envelope to the disk,” the astronomers remarked.

Upcoming findings are detailed in a paper in the Astrophysics Journal Letter.

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PC Cortez et al. 2025. First results from ALPPS: SVS 13A subalfvenic streamer. APJL 992, L31; doi: 10.3847/2041-8213/ae0c04

Source: www.sci.news

ALMA Discovers Heavy Water in Planet-Forming Disk Surrounding Distant Protostar

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An astronomer utilizing the Atacama Large Millimeter/Submillimeter Array (ALMA) has discovered double deuterated water (D2O), commonly known as “heavy water,” in the protoplanetary disk surrounding the protostar V883 Orionis, situated 1,300 light-years away in the Orion constellation. This finding indicates that some of the water found in comets—and even on Earth—might predate the stars themselves, offering transformative insights into the history of water in our solar system.

This artist’s impression illustrates the evolution of heavy water molecules, previously detected in giant molecular clouds, planet-forming disks, and comets, before ultimately reaching Earth. Image credit: NSF / AUI / NRAO of NSF / P. Vosteen / B. Saxton.

Investigating the primordial material from the protoplanetary disk that gave rise to our solar system suggests that water may have been transported to Earth via comet or asteroid impacts.

However, it remains uncertain whether the water ice present on these celestial objects formed primarily during the protoplanetary disk phase or if it is considerably older, originating from parent molecular clouds.

“This detection clearly demonstrates that the water found in the planet-forming disk around V883 Orionis predates the central star and must have formed during the early phases of star and planet formation,” stated Dr. Margot Rehmker, an astronomer at the University of Milan.

“This marks a significant leap in our understanding of the journey of water throughout planet formation and how this water potentially reached the solar system, including Earth, through similar mechanisms.”

The chemical fingerprinting of heavy water indicates that these molecules have withstood the turbulent processes of star and planet formation, traversing billions of kilometers through the cosmos and ending up in planetary systems like ours.

Rather than being completely destroyed and reformed within the disk, a significant portion of this water is inherited from the earliest, most frigid stages of star formation, serving as a cosmic remnant that may still exist on Earth today.

“Until now, it was uncertain whether most of the water in comets and planets was newly formed in young disks such as Orionis V883 or whether it was ‘pure’ from ancient interstellar clouds,” remarked Dr. John Tobin, an astronomer at the NSF National Radio Astronomy Observatory.

“The detection of heavy water using sensitive isotopic isomer ratios (D2oh2O) validates that this water is an ancient relic, forming a crucial link between clouds, disks, comets, and planets.”

“This finding is the first direct evidence that water can traverse through stars unaltered and intact, moving from clouds to the materials that constitute planetary systems.”

The team’s paper is published in this week’s edition of Nature Astronomy.

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M. Riemker et al. Primitive ice within a planet-forming disk identified by heavy water. Nat Astron published online October 15, 2025. doi: 10.1038/s41550-025-02663-y

Source: www.sci.news

ALMA Illuminates the Galaxies of the Early Universe

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As part of the Cristal (CII solved ISM with Star Forming Galaxies using Alma) Investigation, astronomers examined the universe when it was merely a billion years old.

This artist’s impression illustrates masses of star-forming galaxies in the early universe, featuring dark dust marked in red and carbon gases depicted in black. These details have been extensively documented across multiple galaxies in Alma’s Cristal Survey. Image credits: NSF/AUI/NRAO/B. SAXTON.

“Alma’s remarkable capability to penetrate dust and gas enabled us to observe these distant galaxies with astonishing detail,” stated Dr. Rodrigo Ignacio Herrera Camus.

“We’re not merely examining the light emissions. We’re investigating the internal structures of these galaxies and uncovering the processes that transpire within them.”

In the Cristal Survey, astronomers concentrated on a sample of star-forming galaxies exhibiting a conventional relationship between galaxy mass and star formation rate.

Alma’s observations indicated that some galaxies displayed signs of organized rotation, hinting at the formation of early discs, while others exhibited chaotic movements and distorted shapes, indicative of collisions and mergers.

Alma also identified clouds of gas revealed through specific light emissions from ionized carbon, extending far beyond the stellar formation regions. This suggests that the galaxies are enveloped by expansive gas reservoirs, possibly fueling future star formation or being ejected by powerful outflows.

Numerous galaxies displayed star formation occurring in distinct clumps, providing deeper insights into the birth of stars within these early systems.

A portrait of an early galactic layer family, as detailed in a study of the Cristal program. Image credit: Cristal large program.

One particularly intriguing discovery was the identification of an early galaxy known as Cristal-10.

This galaxy shows a significant deficiency in ionized carbon emissions in comparison to its distant light, similar to the characteristics observed in ARP 220, one of the brightest and most concealed galaxies in the local universe.

Subsequent investigations into this galaxy may illuminate the nature and physical state of early interstellar media in the universe.

“Cristal offers detailed data that was unattainable before Alma,” Dr. Herrera Camus remarked.

“I’ve gained a new family portrait of early galactic evolution.”

“These findings challenge existing galaxy formation models and open up new research avenues.”

“The Cristal investigation highlights Alma’s power in studying galaxy evolution during the early universe.”

“By tracing the cold gases and dust that fuel star formation, Alma assists scientists in constructing narratives of how our own Milky Way galaxy developed.”

Source: www.sci.news

Alma Identifies Molecular Activity in the Largest Known Oort Cloud Comet

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Astronomers from the Atacama Large Millimeter/Submillimeter Array (Alma) have made observations of comet C/2014 UN271 (Bernardinelli-Bernstein).

Artist depiction of Comet C/2014 UN271. Image credits: NSF/AUI/NSF/NRAO/M.WEISS.

C/2014 UN271 was identified by astronomers Pedro Berner Dinnelli and Gary Bernstein through images captured in 2014 as part of dark energy research.

The comet spans approximately 140 km (85 miles) in diameter, making it over ten times larger than any known comet.

To date, little has been understood about the behavior of such cold, remote celestial bodies.

Recent findings from Alma revealed the intricate and dynamic jets of carbon monoxide gas erupting from the comet’s nucleus, offering the first direct evidence of what drives its activity in relation to the sun.

“With these measurements, we can understand how this massive, icy world functions,” stated Dr. Nathan Ross, an astronomer affiliated with a U.S. university and NASA’s Goddard Space Flight Center.

“We are observing explosive outgassing patterns that raise new inquiries about the comet’s evolution as it journeys deeper into the inner solar system.”

Alma observed C/2014 UN271 by detecting light from carbon monoxide gas in its atmosphere and thermal radiation when the comet was still distant from the sun.

Thanks to Alma’s exceptional sensitivity and resolution, scientists were able to focus on the very faint signals emitted from such cold and far-off objects.

Building on previous Alma observations that characterized the comet’s substantial nucleus size, the new findings measured the thermal signal to accurately assess the size of the comet and the dust surrounding its nucleus.

Their measurements for the nucleus size and dust mass are in line with earlier Alma observations, affirming it as the largest cloud comet ever identified.

Alma’s precision in measuring these signals enabled this research, providing a clearer understanding of this distant, icy giant.

“This discovery not only represents the first detection of molecular outgassing in a record-setting comet but also offers a rare glimpse into the chemical and dynamic processes of objects from the farthest reaches of the solar system,” the astronomer added.

“As C/2014 UN271 approaches the sun, we anticipate more frozen gases will start to evaporate, revealing further insights into the comet’s primitive composition and the early solar system.”

“Such discoveries help address fundamental questions about the origins of Earth and its waters, as well as the formation of life-supporting environments elsewhere.”

The team’s research paper was published in Astrophysics Journal Letters.

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Nathan X. Ross et al. 2025. Initial detection of molecular activity in the largest known OORT cloud comet: Alma Imaging of The Sun at C/2014 UN271 (Bernardinelli-Bernstein). apjl 986, L22; doi: 10.3847/2041-8213/add526

Source: www.sci.news

Proxima Centauri exhibits intense flare activity and recent Alma observations reveal new insights

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While Proxima Centauri’s flaring activity is well known to astronomers using visible wavelengths, new observations on Atacama’s massive millimeter/sub-millimeter arrays (ALMAs) highlight the extreme activity of stars at radio and millimeter wavelengths.

The concept of violent star flare artists from Proxima Centauri. Image credit: S. Dagnello, nrao/aui/nsf.

Proxima Centauri is a red star, about 4.24 light years away from the constellation of Centaurus.

Discovered in 1915 by Scottish astronomer Robert Innes, the star is invisible to the naked eye.

Its average luminosity is very low, very small compared to other stars, only about one eighth of the mass of the sun.

Proxima Centauri is also known as the Alpha Centauri C, as it is actually part of the Triple Star system.

The separation of the stars from their larger companions, Alpha Centauri A and B, is about 0.2 light-years, equivalent to 400 times the orbit of Neptune.

Proxima Centauri hosts the terrestrial exoplanet Proxima B in a habitable zone of 0.0485 Au.

The stars are well-established as highly active stars and are the primary targets for investigating the effects of star activity on the habitability of planets orbiting Red War.

In the new study, astronomer Kiana Burton at the University of Colorado and astronomer Meredith McGregor at Johns Hopkins University, and colleagues used archival data and new Alma observations to study millimeter-wavelength flare activity.

The small size and strong magnetic field of the Proxima Centauri show that its entire internal structure is convection (unlike the sun, which has both convective and non-reliable layers).

The magnetic field will twist and develop tension, and eventually snap, sending energy and particle flow outwards to what is observed as flares.

“Our solar activity does not remove the Earth’s atmosphere and instead creates beautiful auroras because it has a thick atmosphere and a strong magnetic field to protect the planets,” Dr. McGregor said.

“But we know that Proxima Centauri’s flares are much stronger and there are rocky planets in their habitable zones.”

“What are these flares doing to their atmosphere? Are there any large fluxes of radiation and particles that are chemically altered or perhaps completely eroding at the atmosphere?”

This study represents the first multi-wavelength study using millimeter observations to reveal a new appearance in flare physics.

A total of 463 flare events were reported with 50 hours of ALMA observations using both the full 12-meter array and the 7-M Atacama Compact Array (ACA).twenty four On 1027 ERG, and a short period of 3-16 seconds.

“When you see the flare with Alma, you see electromagnetic radiation, that is, light of various wavelengths,” Dr. McGregor said.

“But this radio-wavelength flaring also gives us a way to track the properties of those particles and understand what is free from the stars.”

To this end, astronomers characterized the stars (so-called flare frequency distribution) and mapped the number of flares as a function of energy.

Typically, the gradient of this distribution tends to follow the power law function. More frequent (lower energy) flares occur more frequently, but larger, more energy flares do not occur regularly.

Proxima Centauri experiences so many flares, researchers have detected many flares within each energy range.

Furthermore, they were able to quantify the asymmetry of the highest energy flares of stars, explaining how the attenuation phase of the flare is much longer than the initial burst phase.

Radio and millimeter wavelength observations help to constrain the energy associated with these flares and their associated particles.

“Millimeter flares look much more frequent,” Dr. McGregor said.

“It’s a different power law than what you see at optical wavelengths.”

“Looking only at the optical wavelengths is missing important information.”

“The Alma is the only millimeter interferometer that is sensitive enough to these measurements.”

Team’s Survey results It was published in Astrophysical Journal.

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Kiana Burton et al. 2025. Proxima Centauri Campaign – First constraint on millimeter flare rate from Alma. APJ 982, 43; doi:10.3847/1538-4357/ada5f2

Source: www.sci.news

Alma finds evidence of oxygen in the majority of known galaxies

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Astronomers using Atacama’s Large Millimeter/Sub-Millimeter Array (ALMA) detected oxygen in the most perilous confirmed galaxy ever discovered. This detection, made by two different teams, suggests that the galaxy is much more chemically mature than expected.

This is the impression of the artist Jades-GS-Z14-0. Image credit: ESO/M. Kornmesser.

Discovered in 2024, the Jades-GS-Z14-0 (GS-Z14 for short) is far apart, and its light took 13.4 billion years to reach us. This means that the universe was under 300 million years old, about 2% of its current age.

“It’s like finding adolescence you only expect from a baby,” said PhD Thunder Shues. Leiden Observatory Candidate and First Author of a paper Accepted for publication in Astrophysical Journal.

“The results show that galaxies are forming very rapidly, mature rapidly, and there is growing evidence that galaxies form much faster than expected.”

Galaxies usually begin life filled with young stars. This is mainly made of light elements such as hydrogen and helium.

As the stars evolve, they create heavier elements like oxygen, which will disperse into the host galaxy after exploding in supernova events.

Researchers thought 300 million years ago that the universe was too young to ripen galaxies with heavy elements.

However, two ALMA studies show that GS-Z14 has about 10 times more heavy elements than expected.

The inset of this image shows Jades-GS-Z14-0 seen in Alma. The two spectra arise from independent analysis of ALMA data by two teams of astronomers. Both discover oxygen radiation, making the universe the most distant detection of oxygen just 300 million years ago. Image credits: alma/eso/naoj/nrao/carniani et al. /schouws et al. /NASA/ESA/CSA/WEBB/STSCI/BRANT ROBERTSON… etc.

“They opened up a new perspective on the first stages of Galaxy’s evolution and were surprised by the unexpected results,” said Dr. Stefano Carniani, an astronomer at the Scola Normal Superore in Pisa and lead author. paper Published in the journal Astronomy and Astrophysics.

“Evidence that galaxies are already matured in the infantile universe raises questions about when and how they formed.”

Oxygen detection allowed astronomers to make distance measurements on the GS-Z14 more accurate.

“ALMA detection measures galaxy distances very accurately to just 0.005% uncertainty,” says PhD Eleonora Parlanti. A student at the Scola Normal Supers in Pisa.

“This level of accuracy is similar to being accurate within 5 cm at a distance of 1 km, but it helps to improve our understanding of distant galactic properties.”

“The galaxy was originally discovered by NASA/ESA/CSA James Webb’s space telescope, but Alma took it to see and accurately determine its huge distance,” said Dr. Leichard Boowens, an astronomer at the Leiden Observatory.

“This shows an incredible synergy between Alma and Webb, revealing the formation and evolution of the first galaxy.”

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Thunder Shues et al. 2025. Detecting [OIII]88μm with Jades-GS-Z14-0 at Z = 14.1793. APJin press; Arxiv: 2409.20549

Stefano Carniani et al. 2025. The eventful life of a bright galaxy at Z = 14: metal enrichment, feedback, and low-gas fractions? A&Ain press; doi: 10.1051/0004-6361/202452451

Source: www.sci.news

New observations from ALMA indicate that planets can form in challenging stellar environments

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Astronomers used the Atacama Large Millimeter/Submillimeter Array (ALMA) to take high-resolution images of eight protoplanetary disks. sigma orionisa star cluster that is irradiated with strong ultraviolet light from a massive star. Surprisingly, they found evidence of gaps and rings in most of the disks. These are the substructures commonly associated with the formation of giant exoplanets.

These ALMA images show the rich disk structure around the star Sigma Orioni. Image credits: ALMA / ESO / JAO / National Astronomical Observatory of Japan / NRAO / Huang others.

“We expected that high levels of radiation within this cluster would inhibit planet formation in the outer regions of these disks,” the Columbia University astronomers said. jane fan.

“But instead, we are seeing signs that planets may be forming at distances of tens of astronomical units from their stars, similar to what we have observed in less harsh environments.”

Previous research has focused on regions of the disk with little ultraviolet (UV) radiation.

This study used ALMA's highest resolution to observe a disk in a much harsher environment.

“These observations suggest that the processes driving planet formation are very robust and can function even under difficult conditions,” said Dr. Huang.

“This gives us even more confidence that planets may be forming in many more places across the galaxy, even in areas previously thought to be too harsh.”

The discovery has important implications for understanding the formation of our own solar system, which likely evolved in a similar high-radiation environment.

These also motivate future studies of disks in more extreme stellar neighborhoods.

Astronomers used ALMA's most extended antenna configuration to obtain unprecedented detail in disk images, achieving a resolution of about 8 AU (astronomical units).

This allowed us to resolve several different gaps and rings on several disks.

The exact nature of these disk structures is still under debate, but it is thought that they either contribute to planet formation or are the result of interactions between the forming planet and the disk's material.

“Our observations suggest that the substructure is common not only in disks near mildly illuminated star-forming regions, but also in disks exposed to intermediate levels of external ultraviolet radiation.” the researchers said.

“If these substructures track planet-disk interactions, ice and gas giant planets may still be forming on Solar System scales in Sigma Orioni, but with very large semi-major axes (50 Giant planet formation in the ~100 AU) region may be rare compared to star formation in nearby regions. ”

“These observations motivate high-resolution imaging of the disk in more extreme ultraviolet environments to investigate the universality of the disk's substructure.”

of findings Coming up this week are: astrophysical journal.

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jane fan others. 2024. High-resolution ALMA observations of the highly structured protoplanetary disk of σ Orionis. APJ 976,132;doi: 10.3847/1538-4357/ad84df

Source: www.sci.news

ALMA discovers over 100 different molecules in a nearby starburst galaxy

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Astronomers using the Atacama Large Millimeter/Submillimeter Array (ALMA) have detected more than 100 molecular species at the center of starburst galaxy NGC 253. This is far more than anything previously observed in galaxies outside the Milky Way.

Artist's impression of the center of starburst galaxy NGC 253. Image credit: NRAO/AUI/NSF.

In the Universe, some galaxies form stars much faster than our Milky Way. These galaxies are called starburst galaxies.

Exactly how such extremely prolific star formation occurs and how it ends is still a mystery.

The probability of star formation is determined by the properties of the raw material from which stars are formed, such as molecular gas, which is a gaseous substance made up of various molecules.

For example, stars form in dense regions within molecular clouds where gravity can work more effectively.

Some time after a star has been actively forming, explosions from existing or dead stars can energize the surrounding material and prevent future star formation.

These physical processes affect the galaxy's chemistry and imprint signatures on the strength of the signals from its molecules.

Because each molecule emits light at a specific frequency, observations over a wide frequency range can analyze its physical properties and provide insight into the mechanism of starbursts.

It was observed by Dr. Nanase Harada of the National Astronomical Observatory of Japan as part of the ALMA Comprehensive High-Resolution Extragalactic Molecular Inventory (ALCHEMI). NGC253 a starburst galaxy located 11.5 million light-years away in the constellation Corina.

They were able to detect more than 100 molecular species in the galaxy's central molecular belt.

This chemical raw material is most abundantly found outside the Milky Way, and includes molecules such as ethanol and the phosphorus-containing species PN, which were first detected beyond the Milky Way.

First, astronomers found that the dense molecular gas likely fuels active star formation in this galaxy.

Each molecule emits at multiple frequencies, and its relative and absolute signal strength varies with density and temperature.

Analysis of numerous signals from several molecular species revealed that the amount of dense gas at the center of NGC 253 is more than 10 times greater than the amount of gas at the center of the Milky Way. This could explain why NGC 253 forms about 30 stars. With the same amount of molecular gas, you can get many times more efficiency.

One mechanism by which molecular clouds compress and become denser is through collisions between them.

At the center of NGC 253, cloud collisions occur where gas streams and stars intersect, creating shock waves that travel at supersonic speeds.

These shock waves vaporize molecules such as methanol and HNCO and freeze them onto ice dust particles.

Once the molecules evaporate as a gas, they can be observed with radio telescopes such as ALMA.

Certain molecules also track ongoing star formation. It is known that complex organic molecules exist in abundance around young stars.

Schematic image of the center of NGC 253. Spectra from the ALCHEMI survey are shown where different tracer species are enriched.Image credits: ALMA / ESO / National Astronomical Observatory of Japan / NRAO / Harada other.

The study suggests that in NGC 253, active star formation creates a hot, dense environment similar to that found around individual protostars in the Milky Way.

The amount of complex organic molecules at the center of NGC 253 is similar to that found around galactic protostars.

In addition to the physical conditions that can promote star formation, the study also uncovered harsh environments left behind by previous generations of stars that could slow the formation of future stars.

When a massive star dies, a massive explosion known as a supernova occurs, releasing energetic particles called cosmic rays.

Molecular composition of NGC 253 revealed by enhancement of species such as H3○+ and HOC+ Molecules in this region are stripped of some of their electrons by cosmic rays at least 1,000 times faster than molecules near the solar system.

This suggests that there is a significant energy input from the supernova, making it difficult for the gas to condense and form a star.

Finally, the ALCHEMI survey provided an atlas of 44 molecular species, double the number obtained in previous studies outside the Milky Way.

By applying machine learning techniques to this atlas, the researchers were able to identify which molecules can most effectively track the star formation story described above from beginning to end.

As explained above with some examples, certain molecular species track phenomena such as shock waves and dense gas that can help star formation.

Young star-forming regions are rich in chemicals, including complex organic molecules.

On the other hand, the developed starbursts show an enhancement of cyanogen radicals, which indicate an energy output in the form of ultraviolet photons from massive stars, which could also hinder future star formation.

“Finding these tracers may help plan future observations to take advantage of the broadband sensitivity improvements expected over this decade as part of the ALMA 2030 development roadmap. “Simultaneous observation of molecular transitions will become more manageable,” the scientists said.

Their paper will appear in Astrophysical Journal Appendix Series.

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Nanase Harada other. 2024. ALCHEMI Atlas: Principal component analysis reveals starburst evolution of NGC 253. APJS 271, 38; doi: 10.3847/1538-4365/ad1937

Source: www.sci.news

ALMA observes water vapor in young star’s protoplanetary disk

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Water molecules are key components in the formation of planetary systems. Astronomers using the Atacama Large Millimeter/Submillimeter Array (ALMA) have detected water vapor in the disk around the young star HL Taurus, where planets may be forming. Their analysis suggests that the hard lower limit for water vapor availability within the interior 17 astronomical units of the Taurus HL system is 3.7 Earth Oceans.

This ALMA image shows water vapor (blue tints) in the protoplanetary disk around HL Taurus. Near the center of the disk, where young stars live, the environment is hotter and the gas brighter. The red ring is a previous ALMA observation showing the distribution of dust around the star.Image credits: ALMA / ESO / National Astronomical Observatory of Japan / NRAO / Facchini other.

Water molecules are undoubtedly one of the most important molecular species in the entire universe.

Water is a highly efficient solvent, so it played a key role in the emergence of life as we know it on Earth.

For this reason, chemical characterization of exoplanetary atmospheres often focuses on detecting this specific molecule.

Water, formed from common hydrogen and oxygen atoms, is so abundant in both gas and ice form that it plays a fundamental role in the physics of planetary system formation.

Dr Stefano Facchini, an astronomer at the University of Milan, said: “We never imagined that we would be able to image oceans of water vapor in areas where planets are likely to form.”

The HL Taurus system is believed to be less than 100,000 years old and has a radius of about 17.9 billion km. It is located 450 light years away in the direction of the constellation Taurus.

The protoplanetary disk of HL Taurus is unusually large and bright, making it a perfect place to look for signs of planet formation.

New ALMA observations reveal that there is at least three times more water inside the disk than in Earth's entire ocean.

Dr Leonardo Testi, an astronomer at the University of Bologna, said: “It is truly amazing that we can not only detect water vapor 450 light-years from us, but also obtain detailed images and spatially resolve it.” said.

Spatially resolved observations with ALMA allow astronomers to determine the distribution of water in different regions of the disk.

“Participating in such an important discovery of the iconic HL Taurus disk was beyond my expectations given my first research experience in astronomy,'' said Dr. Mathieu Vander Donk, an astronomer at the University of Liege. he said.

Dr Facchini said: “Our recent images reveal that significant amounts of water vapor are present at distances from the star that include gaps where planets may now be forming.” said.

“This suggests that this water vapor could influence the chemical composition of planets that form in those regions.”

“To date, ALMA is the only facility capable of spatially resolving water in cold planet-forming disks,” said Professor Wouter Bremings, an astronomer at Chalmers University of Technology.

ESO astronomer Dr Elizabeth Humphreys said: “It's really exciting to be able to witness first-hand in photographs the ejection of water molecules from icy dust particles.”

“The dust particles that make up the disk are the seeds for planet formation, colliding and clumping together to form even larger bodies orbiting the star.”

“Our findings show how the presence of water influences the development of planetary systems, similar to our own solar system about 4.5 billion years ago,” Dr. Facchini said.

of findings It was published in the magazine natural astronomy.

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S. Facchini other. HL Resolved ALMA observations of water in the inner astronomical unit of the Tau disk. Nat Astron, published online on February 29, 2024. doi: 10.1038/s41550-024-02207-w

Source: www.sci.news

ALMA discovers earthquake-like ripples in the disk of an old barred spiral galaxy

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astronomer using Atacama Large Millimeter/Submillimeter Array ALMA observed disk bending waves in BRI 1335-0417, the oldest known spiral galaxy, more than 12 billion years old. This unprecedented observation reveals the galaxy’s dynamic growth pattern, showing the motion of a vertically oscillating disk similar to ripples in a pond. This study is the first time such a phenomenon has been detected in an early galaxy.

This simulation shows how the galactic disk is disturbed and seismic ripples propagate throughout the disk. Image credit: Brand-Hawthorne & Tepper-Garcia, University of Sydney.

Bar structures play an important role in driving galaxy evolution and forming disk structures.

In galaxies, axisymmetric stellar bars exert a gravitational torque on the gas, driving it toward the galactic center and forming concentrated stellar structures such as bulges and core disks.

This process may also promote the accretion of gas onto black holes, which are observed as active galactic nuclei.

Bars can also cause radial migration of gas and stars, which is essential for explaining the stellar kinematics observed in galaxies similar to the Milky Way.

“Thanks to a cutting-edge telescope called ALMA, we have been able to observe the ancient galaxy BRI 1335-0417 in greater detail,” said lead author Dr Takafumi Tsukui, an astronomer at the Australian National University.

“In particular, we were interested in how gas moves within and across galaxies.”

“Gas is a key component for star formation and provides important clues about how galaxies actually drive star formation.”

In this case, Dr. Tsukui and his colleagues were not only able to capture the movement of gas around BRI 1335-0417, but also revealed the formation of seismic waves, a first for this type of early galaxy.

The galaxy’s disk moves similar to the ripples in a pond after a stone is thrown into it.

ALMA detected emission from carbon ions in the galaxy BRI 1335-0417. Image credit: ALMA / ESO / NAOJ / NRAO / T. Tsukui & S. Iguchi, doi: 10.1126/science.abe9680.

“The vertical oscillatory motion of the disk is due to external factors, such as new gas flowing into the galaxy or contact with other small galaxies,” Tsukui said.

“Both possibilities would bombard the galaxy with new fuel for star formation.”

“Furthermore, our study revealed rod-like structures within the disk.”

“The galactic rods can destroy gas and transport it towards the center of the galaxy.”

“The bar discovered at BRI 1335-0417 is the most remote known structure of its kind.”

“Taken together, these results point to the dynamic growth of young galaxies.”

“We know that early galaxies formed stars at much faster rates than modern galaxies,” said co-author Dr Emily Wisnioski, also from the Australian National University.

“This is also true for BRI 1335-0417, which has a similar mass to our Milky Way galaxy but forms stars hundreds of times faster.”

“We wanted to understand how gas is supplied to keep up with this rapid rate of star formation.”

“Spiral structures are rare in the early Universe, and exactly how they form remains unknown.”

“This study also provides important information about the most likely scenario.”

“While it is impossible to directly observe the evolution of galaxies, our observations only provide snapshots, so computer simulations can help piece together the story.”

of findings will appear in Royal Astronomical Society Monthly Notices.

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Takafumi Tsukui other. 2024. Disk bending waves detected in a barred spiral galaxy at redshift 4.4. MNRAS 527 (3): 8941-8949; doi: 10.1093/mnras/stad3588

Source: www.sci.news