Tag Archives: massive

Massive star ultraviolet radiation influences nearby planetary systems

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Astronomers have known for decades that the powerful light emitted by massive stars can disrupt planetary disks of dust and gas that swirl around young stars, the cradles of planetary birth. However, important questions remained unanswered. How fast does this process occur and will there be enough material left to form a planet?

NASA/ESA/CSA Using the James Webb Space Telescope and the Atacama Large Millimeter Array (ALMA), astronomers are now discovering the Orion Nebula, a nursery for stars, and specifically the protoplanetary disk named d203-506. I’m researching. Although it was confined to a small area, it exploded to an abnormally large size. This makes it possible to measure material loss rates with unprecedented precision.

bernet other. We observed the protoplanetary disk d203-506 illuminated by the far-ultraviolet rays of the Orion Nebula.Image credit: Berne other., doi: 10.1126/science.adh2861.

Young, low-mass stars are often surrounded by relatively short-lived protoplanetary disks of dust and gas, which are the raw materials for planet formation.

Therefore, the formation of gas giant planets is limited by processes that remove mass from the protoplanetary disk, such as photoevaporation.

Photoevaporation occurs when the upper layers of a protoplanetary disk are heated by X-rays or ultraviolet protons, raising the temperature of the gas and ejecting it from the system.

Because most low-mass stars form in clusters that also include high-mass stars, protoplanetary disks are expected to be exposed to external radiation and experience photoevaporation due to ultraviolet radiation.

Theoretical models predict that deep ultraviolet light creates a region of photodissociation, a region where ultraviolet photons projected from nearby massive stars strongly influence the gas chemistry on the surface of the protoplanetary disk. However, it has been difficult to observe these processes directly.

Dr. Thomas Howarth of Queen Mary University of London and his colleagues investigated the effects of ultraviolet irradiation using a combination of infrared, submillimeter wave, and optical observations of the protoplanetary disk d203-506 in the Orion Nebula using the Webb and ALMA telescopes.

By modeling the kinematics and excitation of the emission lines detected within the photodissociation region, they found that d203-506 loses mass rapidly due to heating and ionization by deep ultraviolet light.

According to the research team, the rate at which this mass is lost from d203-506 indicates that gas could be removed from the disk within a million years, suppressing the ability of gas giants to form within the system. It is said that there is.

“This is a truly exceptional case study,” said Dr Howarth, co-author of the paper. paper It was published in the magazine science.

“The results are clear: this young star is losing a staggering 20 Earth masses of material per year, suggesting that Jupiter-like planets are unlikely to form in this system.” .”

“The velocities we measured are in perfect agreement with theoretical models and give us confidence in understanding how different environments shape planet formation across the universe.”

“Unlike other known cases, this young star is exposed to only one type of ultraviolet light from a nearby massive star.”

“Because there is no 'hot cocoon' created by higher-energy ultraviolet light, the planet-forming material is larger and easier to study.”

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Olivier Verne other. 2024. Photoevaporation flow caused by far ultraviolet rays observed in a protoplanetary disk. science 383 (6686): 988-992; doi: 10.1126/science.adh2861

Source: www.sci.news

Scientists observe massive outburst from supermassive black hole in far-off galaxy cluster

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Some of the gas erupts from the supermassive black hole located at the center of galaxy cluster SDSS J1531+3414 (abbreviated SDSS J1531) until it reaches a temperature high enough to form numerous star clusters. Cooled down.

Multi-wavelength image of the massive galaxy cluster SDSS J1531+3414.Image credits: NASA / CXC / SAO / Omorui other. / STScI / Tremblay other. / Astron / Loafers / NASA / CXC / SAO / N. Walk.

SDSS J1531 is a huge galaxy cluster containing hundreds of individual galaxies and a huge reservoir of hot gas and dark matter.

At the center of SDSS J1531, two of the cluster's largest galaxies collide with each other.

Surrounding these merging giants are 19 large star clusters called superclusters, arranged in an “S” shape similar to beads on a string.

Dr. Osase Omoruyi and colleagues at Harvard University and the Smithsonian Center for Astrophysics are using NASA's Chandra X-ray Observatory, the LOFAR radio network, and other telescopes to discover how this chain of unusual star clusters formed. I found out what happened.

The discovery of evidence of an ancient mega-eruption in SDSS J1531 provided important clues.

The eruption may have occurred when a supermassive black hole at the center of one of the large galaxies produced a very powerful jet.

As the jet traveled through space, it pulled surrounding hot gas away from the black hole, creating a huge cavity.

“We're already observing this system as it existed 4 billion years ago, when the Earth was just forming,” Omoruyi said.

“This ancient cavity is a fossil of the black hole's influence on its host galaxy and its surroundings, and tells us about important events that occurred almost 200 million years ago in the history of this star cluster.”

Evidence for the cavity comes from bright X-ray emission “wings” seen on Chandra that track dense gas near the center of SDSS J1531.

These wings form the edges of the cavity, and the less dense gas between them is part of the cavity.

LOFAR shows radio waves from the remains of the jet's energetic particles filling a huge cavity.

Taken together, these data provide convincing evidence for an ancient great explosion.

Astronomers also discovered cold and warm gas near the cavity's opening, detected by the Atacama Large Millimeter and Submillimeter Array (ALMA) and Gemini North Telescope, respectively.

They argue that some of the hot gas pushed out of the black hole eventually cooled down to cold, warm gas.

They believe that the tidal effects of the two galaxies merging compressed the gas along a curved path, forming the star cluster in a “string-bead” pattern.

“We reconstructed the sequence of events that may have occurred within this cluster over a wide range of distances and times,” said Dr. Grant Tremblay, also of Harvard University and the Smithsonian Center for Astrophysics.

“It started when a black hole, just one light-year in diameter, formed a cavity about 500,000 light-years wide.”

“This single event triggered the formation of young star clusters almost 200 million years later, each several thousand light-years in diameter.”

Although the authors only looked at the radio waves and cavity from one jet, black holes typically fire two jets in opposite directions.

They also observed radio emissions further out from the galaxy that could be the remains of a second jet, but it was unrelated to the detected cavity.

They speculate that radio and X-ray signals from other eruptions may have diminished to the point where they could no longer be detected.

“We believe the evidence for this large-scale eruption is strong, but further observations from Chandra and LOFAR will confirm the case,” Dr. Omoruyi said.

“We hope to learn more about the origins of the cavities we have already detected and find the cavities we expect to find on the other side of the black hole.”

a paper Regarding the survey results, astrophysical journal.

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Omase Omorui other. 2024. A “string bead” star formation associated with one of the most powerful she-AGN outbursts observed in the Cool Core Galaxy Cluster. APJ, in press. arXiv: 2312.06762

Source: www.sci.news

Astronomers find hundreds of massive gas clouds streaming away from the Milky Way’s center

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Using new 21 cm radio observations made with NSF's Green Bank Telescope, astronomers have discovered that more than 250 clouds of neutral gas are blasting out into interstellar space from the center of the Milky Way. These clouds are likely the product of the same phenomenon that created the Fermi bubble.

The artist's concept is that clouds flowing from the center of the Milky Way are caught up in extremely hot winds and accelerated to speeds of hundreds of kilometers per second. Image credit: NSF/GBO/P. Vosteen.

It has long been known that energetic processes at the center of the Milky Way generate high-velocity hot winds that spread through intergalactic space with temperatures of millions of degrees and speeds of thousands of kilometers per second. Most large galaxies have winds like this.

The serendipitous discovery that some of this hot gas is trapped in cold hydrogen clouds was made by Australia's ATCA telescope, which measured 21cm radio emissions from interstellar hydrogen atoms.

This suggests that there may be an undiscovered population of clouds transporting material away from the Milky Way's core.

Hydrogen clouds are important in their own right, but they also act as probes for hot air.

Conditions in very hot winds are difficult to measure, but just as a few leaves thrown up on Earth indicate the direction and speed of the wind in the area, cold clouds can You can track its status.

The sensitivity of the Green Bank Telescope (GBT) makes it an ideal instrument for detecting faint signals from interstellar hydrogen, but mapping these clouds and understanding their true extent is essential. It wasn't easy.

Dr Felix James 'Jay' Rockman, senior astronomer at Green Bank Observatory, said: 'It took many years to systematically map hundreds of square degrees using GBT in search of weak hydrogen emissions. ” he said.

“Once we identify a few promising candidates, we can follow up with targeted observations with other telescopes to show us even more.”

“This cloud must have been ripped off from a region near the center of the Milky Way galaxy and flung outward by a burst of star formation or black hole activity.”

Some of these clouds have the fastest outflow velocities of any cloud ever observed in the Milky Way, and may even escape from the Milky Way.

In an unexpected development, new data from the APEX telescope reveals that some hydrogen clouds contain molecules and dense cold gas.

“No one would have expected that the clouds violently ejected from the Milky Way would harbor relatively fragile molecular material, but that's what happened,” Rockman said.

Astronomers using the MeerKAT array recently mapped hydrogen in several clouds with high angular resolution, showing that it evolves and gets shredded as it flows into interstellar space.

“These new results open the door to further discoveries,” Dr. Rockman said.

“How clouds that are accelerated to speeds of more than 400 kilometers per second remain stable is a mystery.”

“The chemical processes inside these clouds are very unusual and unexplored.”

Dr. Rockman and his colleague Dr. Enrico Di Teodoro of the University of Florence, findings in AAS243243rd Meeting of the American Astronomical Society, New Orleans, Louisiana, USA.

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Felix Rockman and Enrico di Teodoro. 2024. New investigation of neutral clouds in the Milky Way's core wind. AAS243Abstract #2851

Source: www.sci.news

Webb uncovers massive inactive galaxy with mature stars in the ancient cosmos

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The formation of galaxies through the stepwise hierarchical coassembly of baryons and cold dark matter halos is a fundamental paradigm underpinning modern astrophysics and predicts a significant decline in the number of giant galaxies in the early Universe. . Very massive quiescent galaxies have been observed 1 to 2 billion years after the Big Bang. These form between 300 million and 500 million years ago and are very limiting for theoretical models, as only some models can form massive galaxies this early. The spectrum of newly discovered quiescent galaxy ZF-UDS-7329 reveals features typical of much older stellar populations. Detailed modeling shows that the stellar population formed about 1.5 billion years ago, when dark matter halos with sufficient host mass had not yet assembled in the standard scenario. This observation may indicate the existence of an undetected early population of galaxies and potentially large gaps in our understanding of the nature of early stellar populations, galaxy formation, and/or dark matter.

This web image shows ZF-UDS-7329, a rare massive galaxy that formed very early in the universe. Image credit: Glazebrook other., doi: 10.1038/s41586-024-07191-9.

Galaxy formation is a fundamental paradigm underpinning modern astrophysics, and a significant decrease in the number of massive galaxies in the early universe is predicted.

Very large quiescent galaxies have been observed 1 to 2 billion years after the Big Bang, casting doubt on previous theoretical models.

Professor Carl Glazebrook, from Swinburne University of Technology, said: “We have been tracking this galaxy for seven years, observing it for hours with two of the largest telescopes on Earth to find out its age.” Ta.

“But it was too red and too faint to be measured. In the end, we had to go outside Earth and use the web to see its properties.”

“This was truly a team effort, from the infrared sky survey that began in 2010 to identifying this galaxy as an anomaly, and the many hours spent with the Keck Telescope and the Very Large Telescope. But we couldn’t confirm it, and finally, last year, we spent a lot of effort trying to figure out how to process the web data and analyze this spectrum.”

“We are now beyond the realm of possibility to have identified the oldest giant stationary monster deep in the universe,” said Dr Temmiya Nanayakkara, an astronomer at Swinburne University of Technology.

“This pushes the limits of our current understanding of how galaxies form and evolve.”

“The key question now is how do stars form so quickly, so early in the universe, and how do they form at a time when other parts of the universe are forming stars? “What kind of mysterious mechanism could cause it to suddenly stop forming?”

“Galaxy formation is determined primarily by how dark matter is concentrated.”

“The presence of these extremely massive galaxies in the early universe poses significant challenges to our standard model of cosmology.”

“This is because dark matter structures large enough to accommodate these massive galaxies are unlikely to have formed yet.”

“More observations are needed to help us understand how common these galaxies are and how massive they really are.”

“This could open new doors in our understanding of the physics of dark matter,” Professor Glazebrook said.

“Webb continues to discover evidence that massive galaxies form early.”

“This result sets a new record for this phenomenon. It’s very impressive, but it’s just one object. But we want to discover more. If I If we were to do this, it would seriously disrupt our understanding of galaxy formation.”

This finding is reported in the following article: paper Published in this week’s magazine Nature.

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K. Glazebrook other. A huge galaxy that formed stars at z ~ 11. Nature, published online on February 14, 2024. doi: 10.1038/s41586-024-07191-9

Source: www.sci.news

Webb’s Observation of a Massive Star-Forming Complex in the Large Magellanic Cloud

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Use of Mid-infrared measuring instrument With (MIRI) aboard the NASA/ESA/CSA James Webb Space Telescope, astronomers have captured stunning images of N79, a region of interstellar ionized hydrogen in the Large Magellanic Cloud.

This Hubble image shows star-forming region N79 located 163,000 light-years away in the constellation Sera. Image credit: NASA / ESA / CSA / Webb / M. Meixner.

N79 is a massive star-forming complex spanning about 1,630 light-years in the generally unexplored southwestern region of the Large Magellanic Cloud, a neighboring dwarf galaxy about 163,000 light-years from us.

This region is usually considered a younger version of the 30 Doradus, also known as the Tarantula Nebula.

N79 has a star formation efficiency more than twice that of Doradas 30 over the past 500,000 years.

This particular image centers on one of three giant molecular cloud complexes called N79 South (S1 for short).

The distinctive “starburst” pattern surrounding this bright object is a series of diffraction spikes.

“All telescopes that use mirrors to collect light, like Webb, have this form of artifact resulting from the design of the telescope,” Webb astronomers said.

“For Webb, the six largest starburst spikes appear due to the hexagonal symmetry of Webb's 18 primary mirror segments.”

“Such patterns are only noticeable around very bright and compact objects, where all the light comes from the same place.”

“Most galaxies appear very small to our eyes, but we don't see this pattern because they are dimmer and more spread out than a single star.”

“At the longer wavelengths of light captured by MIRI, Webb's view of N79 shows glowing gas and dust in the region.”

“This is because mid-infrared light can reveal what's going on deep within the cloud (whereas shorter wavelength light is absorbed or scattered by dust particles within the nebula). Still embedded Some protostars also appear in this region.”

Star-forming regions such as N79 are of interest to astronomers because their chemical composition is similar to that of giant star-forming regions observed in the early universe.

“The star-forming regions of our Milky Way galaxy are not producing stars at the same ferocious rate as N79 and have a different chemical composition,” the astronomers said.

“Webb now offers us the opportunity to compare and contrast observations of star formation in N79 with deep telescopic observations of distant galaxies in the early universe.”

“These observations of N79 are part of the Webb program to study the evolution of circumstellar disks and envelopes of forming stars over a wide range of masses and at different evolutionary stages.”

“Webb's sensitivity allows us to detect for the first time disks of planet-forming dust around stars of the same mass as the Sun at distances in the Large Magellanic Cloud.”

Source: www.sci.news

PaintJet creates massive industrial robots for painting large-scale industrial projects

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Construction could be the next major focus for robotics investments. Here in America, our $2 trillion industry employs about 8 million people, the equivalent of one New York City. But even in times of financial boom, these jobs can be difficult to keep filled due to physical demands and other potential hazards.

Industrial painting is ready for automation. After all, large projects involve quite a bit of heavy equipment. As evidenced by the video published by PaintJet, this kind of old technology remains in place, despite some automated twists. Announced in October, the Nashville startup Bravo’s robotic paint sprayer more or less resembles a cherry picker.

CEO Nick Hegeman told TechCrunch that even though it looks like a fairly standard piece of heavy equipment, “we developed 100% of the robotic system. The parts come from industry suppliers. paint Hoses, nozzles and pumps. “We can non-invasively connect to the platform and control both the lift and the robotic system,” he added. “This allows us to expand to our widely established network of equipment rental providers.” can.”

Today, the company announced a $10 million Series A led by Outsiders Fund with participation from Pathbreak Ventures, MetaProp, Builders VC, 53 Stations, and VSC Ventures. This round follows his $3.5 million seed led by Dynamo Ventures and brings his total funding to date to $14.75 million.

Image credits: paint jet

Co-founder and CEO Nick Hegeman has understandably put ongoing staffing issues at the center of the pay increase. “It’s not just about automation. It’s about redefining industry standards, addressing labor shortages, and introducing cost-effective solutions that break the traditional paint mold,” he said in a release. There is. “We are grateful to our investors who support our mission and enable us to expand geographically and into new areas.”

Alongside Bravo’s announcement in October, the company also announced Alpha Shield paint. This is claimed to reduce standard wear and tear from the elements and allow for increased repainting intervals.

Image credits: paint jet

Of course, Paintjet isn’t the only company vying to bring robots into the world of industrial painting. Gray Matter offers painted his arms in a variety of scales. Japanese robotic arm giant Fanuc has also introduced solutions, but so far they cannot reach the heights of the kinds of buildings that Paintjet is working on at Bravo.

The startup targets construction companies as its primary user base. Current client list includes Prologis, Clayco, Layton Construction, and Brinkman Constructors.

Paintjet’s workforce remains small, with 24 full-time employees. A portion of the new funding will be used to increase sales and operations staff. The company also moved its headquarters from Nashville to Virginia “to support our entry into the marine business and to increase our engineering headcount to expand our technology stack and distribute more broadly,” Hageman said. That’s what it means.

Source: techcrunch.com