Tag Archives: distribution

Astronomers Map the Distribution of Ordinary Matter Across the Universe

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Astronomers are making significant strides in comprehending how matter behaves and interacts in space utilizing fast radio bursts (FRB). They have found that over three-quarters of the universe’s ordinary material is concealed within sparse intergalactic gases, and they have also identified the furthest FRB event recorded to date.

This artist’s concept illustrates the density regions and red blank areas of the universe’s web in blue. Image Credit: Jack Madden/Illustristng/Ralf Konietzka/Liam Connor, CFA.

For many years, it has been established that at least half of the normal, predominantly proton-based baryonic material in the universe has gone unaccounted for.

Previous approaches by astronomers employed methods like X-ray and ultraviolet observations to gather significant clues regarding this missing mass, which manifests as extremely thin warm gases between galaxies.

The challenge arises from the high-temperature, low-density gas that remains mostly invisible to most telescopes, leaving scientists unable to assess its presence or distribution.

This is where FRBs come into play – brief, intense radio signals emitted by distant galaxies that researchers have recently demonstrated could measure baryonic matter in space, although its location remained a mystery until now.

In the latest study, scientists examined 60 FRBs, with the most distant FRB recorded at 1,174 million light-years (FRB 20200120E) from Messier 81 and reaching up to 9.1 billion light-years (FRB 20230521b).

This enabled them to pinpoint the missing material within intergalactic spaces or the intergalactic medium (IGM).

“The ‘baryon problem’ was never in doubt,” stated Dr. Liam Connor, an astronomer at the Harvard & Smithsonian Center for Astrophysics. “The issue has always been about its location. Now with FRBs, we’ve established that three-quarters of it exists between galaxies in the cosmic web.”

By analyzing the delays in each FRB signal as it traveled through space, Dr. Connor and his colleagues tracked the gaseous medium along its path.

“FRBs function like flashlights in space, illuminating the intergalactic medium. By accurately gauging how the light slows down, we can assess this medium, whether it’s starkly visible or barely detectable,” Dr. Connor explains.

The findings are revealing—approximately 76% of the universe’s baryonic matter resides within the IGM.

Additionally, about 15% is found in galaxy halos, with a minor fraction embedded within stars and cool galactic gases.

This distribution aligns with predictions made by advanced cosmological simulations, yet this is the first instance of direct confirmation.

“This marks a triumph for contemporary astronomy,” noted Dr. Vikram Ravi, an astronomer from California.

“Thanks to FRBs, we are now approaching a new understanding of the universe’s structure and composition.”

“These brief flashes enable us to trace the invisible baryonic matter filling the expansive voids between galaxies,” he added.

“Baryons are pulled into galaxies by gravity; however, supermassive black holes and supernova explosions can expel them back into the IGM, cooling cosmic temperatures when they spiral out of control,” commented Dr. Connor.

“Our findings indicate that this feedback mechanism is effective, suggesting gas must be displaced from galaxies into the IGM.”

The team’s results are published today in the journal Nature Astronomy.

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L. Connor et al. Gas-rich cosmic web unveiled by the partition of missing baryons. Nature Astronomy Published online on June 16th, 2025. doi:10.1038/s41550-025-02566-y

Source: www.sci.news

Magnetic Flares Could Be Key to the Formation and Distribution of Gold and Other Heavy Elements

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Since the Big Bang, the early universe has contained hydrogen, helium, and a minimal amount of lithium. Heavier elements, such as iron, were formed within stars. Yet, one of astrophysics’ greatest enigmas is how the first elements heavier than iron, like gold, were created and dispersed throughout the cosmos. A recent study by astronomers at Columbia University and other institutions suggests that a single flare from a magnetar could generate 27 equivalent masses of these elements simultaneously.

Impressions of Magnetar artists. Image credit: NASA’s Goddard Space Flight Center/S. Wesinger.

For decades, astronomers have theorized about the origins of some of nature’s heaviest elements, like gold, uranium, and platinum.

However, a fresh examination of older archival data indicates that up to 10% of these heavy elements in the Milky Way may originate from the emissions of highly magnetized neutron stars, known as magnetars.

“Until recently, astronomers largely overlooked the role that magnetars, the remnants of supernovae, might play in the formation of early galaxies,” remarked Todd Thompson, a professor at Ohio State University.

“Neutron stars are incredibly unique, dense objects known for their large size and strong magnetic fields. They are similar to black holes but not quite the same.”

The origin of heavy elements has long been a mystery, but scientists have understood that these elements can only form under specific conditions through a process known as the R process (or rapid neutron capture process).

This process was observed in 2017 when astronomers detected a collision between two super-dense neutron stars.

This event was captured using NASA telescopes and the LIGO gravitational wave observatory, providing the first direct evidence that heavy metals can be produced by celestial phenomena.

However, subsequent evidence suggests that neutron star collisions may not form heavy elements swiftly in the early universe, indicating that additional mechanisms might be necessary to account for all these elements.

Based on these insights, Professor Thompson and his colleagues realized that powerful magnetar flares could act as significant ejectors of heavy elements. This conclusion was validated by the observation of the SGR 1806-20 magnetar flare that occurred 20 years ago.

By analyzing this flare event, the researchers found that the radioactive decay of the newly formed elements aligns with theoretical predictions concerning the timing and energy released by magnetar flares after ejecting heavy R-process elements.

“This is the second time we’ve observed direct evidence of where these elements are produced, first linked to neutron star mergers,” stated Professor Brian Metzger from Columbia University.

“This marks a significant advancement in our understanding of heavy element production.”

“We are based at Columbia University,” mentioned Anildo Patel, a doctoral candidate at the institution.

The researchers also theorized that magnetar flares generate heavy cosmic rays and very fast particles, the origins of which remain unclear.

“I am always excited by new ideas about how systems and discoveries in space operate,” said Professor Thompson.

“That’s why seeing results like this is so thrilling.”

The team’s paper was published in The Astrophysical Journal Letters.

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Anirudh Patel et al. 2025. Direct evidence for R-process nuclear synthesis in delayed MeV radiation from SGR 1806-20 magnetar giant flares. ApJL 984, L29; doi: 10.3847/2041-8213/ADC9B0

Source: www.sci.news

Physicists’ Discovery Unveils Distribution of Strong Forces Within Protons

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The physics of proton gravitational form factors and their understanding in quantum chromodynamics have advanced significantly over the past two decades through both theory and experiment.a new paper inside modern physics review We provide an overview of this progress, highlighting the physical insights revealed by studies of the gravitational form factor and reviewing its interpretation in terms of the mechanical properties of protons.

A 2D representation of the quark contribution to the force distribution within the proton as a function of distance from the proton center. Light gray shading and long arrows indicate areas of stronger force, while dark gray shading and short arrows indicate areas of weaker force. Left panel: Normal force as a function of distance from center. The arrows change size and always point radially outward. Right panel: tangential force as a function of distance from center. The force changes direction and magnitude as indicated by the direction and length of the arrow. The sign of the force changes around 0.4 fm from the proton center. Image credit: Burkert other., doi: 10.1103/RevModPhys.95.041002.

“This measurement reveals insight into the environment experienced by the proton's components,” said Volker Burkert, principal investigator at the Jefferson Institute.

“A proton is made up of three quarks held together by a strong force.”

“At its peak, this amounts to more than four tons of force that would have to be applied to the quark to pull it out of the proton.”

“Of course, it is not possible in nature to separate just one quark from a proton because quarks have a property called color.”

“Protons have three colors mixed with quarks, and appear colorless from the outside. This is a requirement for them to exist in the universe.”

“When you try to extract a colored quark from a proton, the energy you invested in separating the quarks is used to create a meson, a pair of colorless quark and antiquark, leaving behind a colorless proton (or neutron).”

“In other words, the number four tons represents the strength of the force inherent in protons.”

The result is only the second of the mechanical properties of the protons to be measured.

Mechanical properties of protons include internal pressure (measured in 2018), mass distribution (physical size), angular momentum, and shear stress (shown here).

This result was made possible by predictions from half a century ago and data from 20 years ago.

In the mid-1960s, nuclear physicists realized that if they could observe how gravity interacted with subatomic particles like protons, such experiments could directly reveal the mechanical properties of protons. It was theorized that

“But at the time, we had no choice. For example, if you compare gravity to electromagnetic forces, there's a difference of 39 orders of magnitude. So it's pretty hopeless, right?” said Latifa El-Adhriri, a staff scientist at the Jefferson Institute. .

This data comes from experiments conducted at the Continuous Electron Beam Accelerator Facility (CEBAF) at the Jefferson Research Institute.

A typical CEBAF experiment involves a high-energy electron interacting with another particle by exchanging a packet of energy and a unit of angular momentum called a virtual photon with the particle. The energy of an electron determines which particles it interacts with in this way and how it reacts.

In the experiment, a high-energy beam of electrons interacting with protons inside a target of liquefied hydrogen gas exerted a much greater force on the protons than the four tons needed to pull out the quark/antiquark pair.

“We have developed a program to study deep virtual Compton scattering,” said Dr. El-Adrili.

“This is where electrons exchange virtual photons with protons.”

“And in the final state, the proton stays the same but recoils, and you actually produce one very high-energy photon, and you also get a scattered electron.”

“At the time we acquired the data, we did not know that beyond the intended 3D imaging with these data, we were also collecting the data needed to access the mechanical properties of the protons.”

“It turns out that this particular process, the highly virtual Compton scattering, may be related to how gravity interacts with matter.”

“A general version of this relationship is stated in Einstein's 1973 textbook on general relativity.gravityWritten by Charles W. Meisner, Kip S. Thorne, and John Archibald Wheeler. ”

“In it, they say, “A massless spin 2 field would give rise to a force indistinguishable from gravity, because a massless spin 2 field would couple with a stress-energy tensor in the same way as a gravitational interaction.'' It is written as 'It is from.'.'.

“Thirty years later, theorist Maxim Polyakov continued this idea and established a theoretical foundation linking deep virtual Compton scattering processes and gravitational interactions.”

“This theoretical breakthrough establishes a relationship between measurements of deep virtual Compton scattering and the gravitational shape factor.”

“And we were able to take advantage of that for the first time and bring out the pressure that we gave during the game.” Nature A paper was published in 2018 and now normal and shear forces are being studied,” Dr. Burkert said.

“A more detailed explanation of the relationship between deep virtual Compton scattering processes and gravitational interactions is provided in a new paper describing the first results obtained from this study.”

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V.D. Burkert other. 2023. Colloquium: Gravitational shape factor of protons. Rev.Mod. Physics 95(4):041002; doi: 10.1103/RevModPhys.95.041002

Source: www.sci.news