Gravitational-wave innovation could help unlock cosmic secrets

Gravitational-wave innovation could help unlock cosmic secrets

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New frontiers in the study of the universe and gravitational waves have been opened following a breakthrough by researchers at the University of the West of Scotland (UWS).

The pioneering development of thin-film technology promises to improve the sensitivity of current and future gravitational-wave detectors. Developed by academics at UWS’s Institute of Thin Films, Sensors and Imaging (ITFSI), the innovation could improve our understanding of the nature of the universe. The research is published in the journal Applied optics.

Gravitational waves, first predicted by Albert Einstein’s theory of general relativity, are ripples in the fabric of spacetime caused by the most energetic events in the cosmos, such as black hole mergers and neutron star collisions. Detecting and studying these waves provides invaluable insights into the fundamental nature of the universe.

Dr. Carlos Garcia Nuez, a professor in the School of Computing, Engineering and Physical Sciences at UWS, said: “At the Institute of Thin Films, Sensors and Imaging, we are working hard to push the limits of thin-film materials by exploring new techniques for deposit them, controlling their properties in order to meet the requirements of current and future sensing technology for gravitational wave sensing”.

“The development of high-reflection mirrors with low thermal noise opens up a wide range of applications, ranging from the detection of gravitational waves from cosmological events, to the development of quantum computers.”

The technique used in this work, originally developed and patented by Professor Des Gibson, director of the UWS’s Institute of Thin Films, Sensors and Imaging, could enable the production of thin films that achieve low levels of ‘thermal noise’. Reducing this type of noise in mirror coatings is essential to increase the sensitivity of current gravitational-wave detectors that enable detection of a wider range of cosmological events, and could be implemented to improve other high-precision devices, such as atomic clocks or quantum computers.

Professor Gibson said: ‘We are thrilled to unveil this cutting-edge thin-film gravitational-wave sensing technology. This breakthrough represents a significant step forward in our ability to explore the universe and unlock its secrets through the study of gravitational waves. Gravitational forces. We believe this advance will accelerate scientific progress in this field and open new avenues for discovery.”

“UWS thin-film technology has already undergone extensive testing and validation in collaboration with renowned scientists and research institutes. The results have been met with great enthusiasm, fueling anticipation for its future impact in the field of astronomy of gravitational waves. The coating deposition technology is being marketed by UWS spinout company, Albasense Ltd.”

The development of low thermal noise coatings will not only make the next generation of gravitational wave detectors more precise and sensitive to cosmic events, but will also provide new solutions to atomic clocks and quantum mechanics, both highly relevant to the sustainable development goals of United Nations 7, 9 and 11.

More information:
Carlos Garcia Nuez et al, Amorphous dielectric optical coatings deposited by plasma ion-assisted electron beam evaporation for gravitational wave detectors, Applied optics (2023). DOI: 10.1364/AO.477186

#Gravitationalwave #innovation #unlock #cosmic #secrets

Webb reveals secrets of early universe through deep field, peers into stellar nurseries – NASASpaceFlight.com

Webb reveals secrets of early universe through deep field, peers into stellar nurseries - NASASpaceFlight.com

With the help of the joint NASA/European Space Agency/Canadian Space Agency James Webb Space Telescope (JWST), scientists are peering deep into the universe and uncovering secrets previously hidden from visible and X-ray telescopes. The JWST Advanced Deep Extragalactic Survey (JADES) used Webb’s incredible deep field sensing capabilities to create a deep field that shows more than 45,000 galaxies and unlocks some of the secrets of the early universe.

Another team used Webb’s immense sensitivity to infrared light to peer behind the thick dust within the bars of a barred spiral galaxy. Behind the dust within the bars of the galaxy were hundreds of bubbles of gas where hot young stars are forming and growing.

JADES data reveals 45,000 galaxies, unlocks secrets of early universe

In the fields of astrophysics and cosmology, one question has existed in the minds of scientists for centuries: when did our universe form and how did the first stars and galaxies form? In recent decades, various telescopes, such as the Hubble Space Telescope and ground-based observatories, have been used to create huge mosaics of portions of the sky called deep fields. Hubble’s 1995 Deep Field is among the most popular images of our universe ever created, and subsequent deep fields have allowed scientists to peer deeper and deeper into our universe by increasing exposure times.

However, Hubble is only so powerful and is limited by its 2.4-metre mirror. Webb’s mirror, launched with the observatory in December 2021, is nearly three times the size of Hubble’s mirror, at 6.5 metres. Webb’s mirror’s larger size, powerful instruments, and infrared sensitivity allowed him to create some of the deepest deep fields of all time, with one of JADES’ first deep fields pinpointing galaxies that existed when the universe was less than 600 million years old – and an incredible feat given Webb’s young age.

A deep field taken by Webb as part of JADES. This image shows an area of ​​the sky known as GOODS-South, with more than 45,000 galaxies dotting the black sea of ​​space. (Credit: NASA/ESA/CSA/Brant Robertson/Ben Johnson/Sandro Tacchella/Marcia Rieke/Daniel Eisenstein/Alyssa Pagan)

JADES is one of the largest programs allotted time in Webb’s freshman year of science, with 32 days of that freshman year devoted to gathering data for JADES and creating incredible deep fields. Much of the JADES data is yet to come, but the team is already making groundbreaking discoveries that will change astrophysics and cosmology forever.

With JADES, we want to answer many questions, such as: how did the first galaxies assemble? How fast did stars form? Why do some galaxies stop forming stars? said JADES co-lead Marcia Rieke of the University of Arizona.

Using Webb’s data, a team within JADES, led by Ryan Endsley of the University of Texas at Austin, studied galaxies that existed between 500 million and 850 million years after the formation of the universe. This specific period of time, which is referred to as the epoch of reionization, is when much of the gas that clouded the energetic light in the early universe disappeared in a process called reionization. Scientists aren’t entirely sure what led to the reionization of the gas, but they believe supermassive black holes or young galaxies may have played a significant role in the reionization.

Endsley et al. used Webb’s near-infrared spectrograph (NIRSpec) to find and study galaxies that existed during the epoch of reionization. NIRSpec specifically looked for star formation signatures and was able to identify many of these signatures.

Almost every single galaxy we’re finding shows these unusually strong emission line signatures that indicate intense recent star formation. These early galaxies were very good at making hot, massive stars, Endsley said.

But how did these young stars influence the reionization of the gas?

The stars forming within the star-forming regions identified by NIRSpec were massive and extremely luminous, meaning they emitted extraordinarily large amounts of ultraviolet light. This ultraviolet light would ionize the gas surrounding the stars, and given the large numbers of these young stars within galaxies in the early universe, Endsley et al. they believe these young galaxies could be the main driver behind the reionization of gas during the reionization epoch.

Furthermore, Endlsey et al. found that these young galaxies probably experienced periods of extreme star formation separated by periods of slow star formation. Periods of extreme star formation would likely have been caused by galaxies absorbing massive clumps of gas and other materials used up during the star formation process. On the flip side, the massive stars within these galaxies may have exploded rapidly, which would have injected large amounts of energy into their surroundings and prevented the gas from condensing and forming new stars.

As mentioned above, the deep fields created by programs like JADES allow scientists to peer into the earliest periods of the universe and have given scientists the ability to discover galaxies that existed when the universe was less than 600 million years old. Several teams within JADES are specifically looking for galaxies that existed when the universe was less than 400 million years old. Finding and studying these galaxies will allow scientists to explore features of the early universe, especially how star formation differed in the early universe compared to what they see now.

However, how do scientists determine how far away a galaxy is and when it existed in the universe?

Whenever light is emitted from a cosmic object, that light travels in waves throughout the universe. As the universe is expanding, these light waves stretch into longer wavelengths and become redder. This phenomenon is called redshift, and when an object’s redshift is measured, scientists are able to determine how far away it is and when it existed. An object’s redshift is typically measured by looking at the spectrum of a galaxy, which shows a collection of wavelengths representing the contents of the galaxy. However, redshift can also be measured by imaging a galaxy with a variety of filters that cover narrow bands of color, resulting in images with varying levels of brightness. The latter method allows researchers to determine the redshifts of several thousand galaxies simultaneously.

Image of Webb’s Deep Field Compass by GOODS-South. (Credit: NASA/ESA/CSA/Brant Robertson/Ben Johnson/Sandro Tacchella/Marcia Rieke/Daniel Eisenstein/Alyssa Pagan)

Led by Kevin Hainline of the University of Arizona, a team of JADES scientists used Webb’s near-infrared camera (NIRCam) to obtain measurements of the redshift, known as photometric redshifts, of galaxies in the inside of JADES data. NIRCam has identified over 700 galaxies that could have existed when the universe was between 370 million and 650 million years old.

Previously, the first galaxies we could see looked like little specks. Yet those spots represent millions or even billions of stars at the beginning of the universe. Now we can see that some of them are actually extended objects with visible structure. We can see clusters of stars being born just a few hundred million years after the beginning of time, Hainline said.

Finding star formation in the early universe is much more complicated than we thought, Rieke said.

Before Webb, discovering and measuring redshift galaxies was extremely difficult, with only a few dozen galaxies observed with a redshift greater than eight (which is equivalent to when the universe was less than 650 million years old). . In less than a year of scientific observations, Webb and JADES have already discovered thousands of galaxies with redshifts greater than eight.

JADES results were presented at the 242nd meeting of the American Astronomical Society.

Discovering the secrets behind the dust of NGC 5068

Webb continues to uncover the secrets of our universe by peering behind the dusty bars of the barred spiral galaxy NGC 5068. Using NIRCam and the mid-infrared (MIRI) instrument, Webb imaged NGC 5068 in both the near and mid-infrareds, giving scientists a glimpse into the depths of the barred galaxy. Webb envisioned the galaxy as part of a campaign to develop a database of stellar nurseries within nearby galaxies.

Composite image of NGC 5068 using MIRI and NIRCam images. (Credits: ESA/Webb/NASA/CSA/J. Lee/PHANGS-JWST Team)

NGC 5068 is located about 20 million light-years away in the constellation Virgo and has long been thought to host stellar nurseries, areas of hot gas and dust where star formation typically occurs. Stellar nurseries not only trigger star formation within them, but also serve as places where hot, young stars grow and develop into main-sequence stars.

Areas of star formation within galaxies are of interest to scientists due to their relevance to several fields of cosmology and astrophysics. Star formation, as discussed above, is thought to have changed dramatically throughout the history of the universe, so understanding star formation during different periods of our universe’s history may prove extremely important in determining how the universe was shaped in what it is today. Additionally, Webb’s incredible observations can be used in tandem with observations from other telescopes such as the Hubble Space Telescope and the Atacama large millimeter/submillimeter array to create a detailed look at the star formation process.

Webb’s infrared sensitivity allows him to see beyond the dust within NGC 5068, allowing the observatory to identify stellar nurseries and the processes and environments that enable star formation. With the combined capabilities of MIRI and NIRCam, Webb is able to observe star formation processes as they occur and the swirling structures of the environments surrounding the stellar nurseries where star formation occurs.

(Main image: (top left) Webb’s JADES deep field of GOODS-South, (bottom right) Webb’s image of NGC 5068. Credits: (top left) NASA/ESA/CSA/ Brant Robertson/Ben Johnson/Sandro Tacchella/Marcia Rieke /Daniel Eisenstein/Alyssa Pagan, (bottom right) ESA/Webb/NASA/CSA/J. Lee/PHANGS-JWST Team)


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Behind galactic bars: The Webb telescope unlocks the secrets of star formation

Webb Composite NGC 5068

Webb Composite NGC 5068

This image of the barred spiral galaxy NGC 5068 is a composite taken from two of the James Webb Space Telescopes’ instruments, MIRI and NIRCam. Credits: ESA/Webb, NASA and CSA, J. Lee and the PHANGS-JWST team

James Webb Space Telescope has captured a detailed image of the barred spiral galaxy NGC 5068. Part of a project to record star formation in nearby galaxies, this initiative provides significant insights into various astronomical fields. The telescopes ability to see through gas and dust, typically hiding star formation processes, offers unique views into this crucial aspect of galactic evolution.

A delicate tracery of dust and bright star clusters threads across this image from the James Webb Space Telescope. The bright tendrils of gas and stars belong to the barred spiral galaxy NGC 5068, whose bright central bar is visible in the upper left of this image a composite from two of Webbs instruments. NASA Administrator Bill Nelson revealed the image on June 2 during an event with students at the Copernicus Science Centre in Warsaw, Poland.

NGC 5068 Webb MIRI

In this image of the barred spiral galaxy NGC 5068, from the James Webb Space Telescopes MIRI instrument, the dusty structure of the spiral galaxy and glowing bubbles of gas containing newly-formed star clusters are particularly prominent. Three asteroid trails intrude into this image, represented as tiny blue-green-red dots. Asteroids appear in astronomical images such as these because they are much closer to the telescope than the distant target. As Webb captures several images of the astronomical object, the asteroid moves, so it shows up in a slightly different place in each frame. They are a little more noticeable in images such as this one from MIRI, because many stars are not as bright in mid-infrared wavelengths as they are in near-infrared or visible light, so asteroids are easier to see next to the stars. One trail lies just below the galaxys bar, and two more in the bottom-left corner. Credit: ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST Team

NGC 5068 lies around 20 million light-years from Earth in the constellation Virgo. This image of the central, bright star-forming regions of the galaxy is part of a campaign to create an astronomical treasure trove, a repository of observations of star formation in nearby galaxies. Previous gems from this collection can be seen here (IC 5332) and here (M74). These observations are particularly valuable to astronomers for two reasons. The first is because star formation underpins so many fields in astronomy, from the physics of the tenuous plasma that lies between stars to the evolution of entire galaxies. By observing the formation of stars in nearby galaxies, astronomers hope to kick-start major scientific advances with some of the first available data from Webb.

NGC 5068 Webb NIRCam

This view of the barred spiral galaxy NGC 5068, from the James Webb Space Telescopes NIRCam instrument, is studded by the galaxys massive population of stars, most dense along its bright central bar, along with burning red clouds of gas illuminated by young stars within. This near-infrared image of the galaxy is filled by the enormous gathering of older stars which make up the core of NGC 5068. The keen vision of NIRCam allows astronomers to peer through the galaxys gas and dust to closely examine its stars. Dense and bright clouds of dust lie along the path of the spiral arms: These are H II regions, collections of hydrogen gas where new stars are forming. The young, energetic stars ionize the hydrogen around them, creating this glow represented in red. Credit: ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST Team

The second reason is that Webbs observations build on other studies using telescopes including the Hubble Space Telescope and ground-based observatories. Webb collected images of 19 nearby star-forming galaxies which astronomers could then combine with Hubble images of 10,000 star clusters, spectroscopic mapping of 20,000 star-forming emission nebulae from the Very Large Telescope (VLT), and observations of 12,000 dark, dense molecular clouds identified by the Atacama Large Millimeter/submillimeter Array (ALMA). These observations span the electromagnetic spectrum and give astronomers an unprecedented opportunity to piece together the minutiae of star formation.

With its ability to peer through the gas and dust enshrouding newborn stars, Webb is particularly well-suited to explore the processes governing star formation. Stars and planetary systems are born amongst swirling clouds of gas and dust that are opaque to visible-light observatories like Hubble or the VLT. The keen vision at infrared wavelengths of two of Webbs instruments MIRI (Mid-Infrared Instrument) and NIRCam (Near-Infrared Camera) allowed astronomers to see right through the gargantuan clouds of dust in NGC 5068 and capture the processes of star formation as they happened. This image combines the capabilities of these two instruments, providing a truly unique look at the composition of NGC 5068.

The James Webb Space Telescope stands as the apex of space science observatories worldwide. Tasked with demystifying enigmas within our own solar system, Webb will also extend its gaze beyond, seeking to observe distant worlds orbiting other stars. In addition to this, it aims to delve into the cryptic structures and the origins of our universe, thereby facilitating a deeper understanding of our position within the cosmic expanse. The Webb project is an international endeavor spearheaded by NASA, conducted in close partnership with the European Space Agency (ESA) and the Canadian Space Agency.


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Secrets of the hypernuclei flux: first observations at the relativistic heavy ion collider

Particle Collision Hypernuclei Flow Concept

Particle Collision Hypernuclei Flow Concept

Physicists at the Relativistic Heavy Ion Collider (RHIC) have made the first observation of the directed flow of hypernuclei, rare nuclei containing at least one hyperon, in particle collisions. Hyperons, which contain a strange quark, are thought to be abundant in neutron stars, one of the densest objects in the universe. By simulating these conditions in the laboratory, researchers aim to understand the interactions between hyperons and nucleons.

Particle collisions offer a new way to study the interactions of hyperon particles with normal nuclear building blocks, potentially providing insight into the properties of neutron stars.

In a groundbreaking study, RHIC scientists observed the directed flow of hypernuclei during particle collisions. This rare matter, abundant in neutron stars, was examined under simulated conditions, providing information on interactions crucial for understanding[{” attribute=””>neutron star structures. The observations, mirroring regular nuclei flow patterns, will help enhance theoretical models of neutron stars.

Physicists studying particle collisions at the Relativistic Heavy Ion Collider (RHIC) have published the first observation of directed flow of hypernuclei. These short-lived, rare nuclei contain at least one hyperon in addition to ordinary protons and neutrons. Hyperons contain at least one strange quark in place of one of the up or down quarks that make up ordinary nucleons (the collective name for protons and neutrons). Such strange matter is thought to be abundant in the hearts of neutron stars, which are among the densest, most exotic objects in the universe. While blasting off to neutron stars to study this exotic matter is still the stuff of science fiction, particle collisions could give scientists insight into these celestial objects from a laboratory right here on Earth.

The conditions in a neutron star may still be far from what we reach at this moment in the laboratory, but at this stage its the closest we can get, said Xin Dong, a physicist from the U.S. Department of Energys Lawrence Berkeley National Laboratory (LBNL) who was involved in the study. By comparing our data from this laboratory environment to our theories, we can try to infer what happens in the neutron star.

Neutron Star Insight From Particle Collisions

Neutron stars are compact objects formed when massive stars collapse at the end of their lives. Tracking how hypernuclei flow collectively in high-energy heavy ion collisions could help scientists learn about hyperon-nucleon interactions in the nuclear medium and understand the inner structure of neutron stars. Credit: STAR Collaboration

The scientists used the STAR detector at RHIC, a DOE Office of Science user facility for nuclear physics research at Brookhaven National Laboratory, to study the flow patterns of the debris emitted from collisions of gold nuclei. Those patterns are triggered by the enormous pressure gradients generated in the collisions. By comparing the flow of hypernuclei with that of similar ordinary nuclei made only of nucleons, they hoped to gain insight into interactions between the hyperons and nucleons.

In our normal world, nucleon-nucleon interactions form normal atomic nuclei. But when we move into a neutron star, hyperon-nucleon interactionswhich we dont know much about yetbecome very relevant to understanding the structure, said Yapeng Zhang, another member of STAR from the Institute of Modern Physics of the Chinese Academy of Sciences, who led the data analysis together with his student Chenlu Hu. Tracking how hypernuclei flow should give the scientists insight into the hyperon-nucleon interactions that form these exotic particles.

The data, just published in the journal Physical Review Letters, will provide quantitative information theorists can use to refine their descriptions of the hyperon-nucleon interactions that drive the formation of hypernucleiand the large-scale structure of neutron stars.

There are no solid calculations to really establish these hyperon-nucleon interactions, said Zhang. This measurement may potentially constrain theories and provide a variable input for the calculations.

Go with the flow

Previous experiments have shown that the flow patterns of regular nuclei generally scale with massmeaning the more protons and neutrons a nucleus has, the more the nuclei exhibit collective flow in a particular direction. This indicates that these nuclei inherit their flow from their constituent protons and neutrons, which coalesce, or come together, because of their interactions, which are governed by the strong nuclear force.

The STAR results reported in this paper show that hypernuclei follow this same mass-scaling pattern. That means hypernuclei most likely form via the same mechanism.

In the coalescence mechanism, the nuclei (and hypernuclei) form this way depending on how strong the interactions are between the individual components, Dong said. This mechanism gives us information about the interaction between the nucleons (in nuclei) and nucleons and hyperons in hypernuclei.

RHIC STAR Detector

A side view of the Solenoidal Tracker at RHIC (STAR) experiment at the Relativistic Heavy Ion Collider (RHIC), a particle collider for nuclear physics research at the U.S. Department of Energys Brookhaven National Laboratory. Credit: Brookhaven National Laboratory

Seeing similar flow patterns and the mass scaling relationship for both normal nuclei and hypernuclei, the scientists say, implies that the nucleon-nucleon and hyperon-nucleon interactions are very similar.

The flow patterns also convey information about the matter generated in the particle smashupsincluding how hot and dense it is and other properties.

The pressure gradient created in the collision will induce some asymmetry in the outgoing particle direction. So, what we observe, the flow, reflects how the pressure gradient is created inside the nuclear matter, Zhang said.

The measured flow of hypernuclei may open a new door to study hyperon-nucleon interactions under finite pressure at high baryon density.

The scientists will use additional measurements of how hypernuclei interact with that medium to learn more about its properties.

The benefits of low energy

This research would not have been possible without the versatility of RHIC to operate over such a wide range of collision energies. The measurements were made during Phase I of the RHIC Beam Energy Scana systematic study of gold-gold collisions ranging from 200 GeV per colliding particle pair down to 3 GeV.

To reach that lowest energy, RHIC operated in fixed-target mode: One beam of gold ions traveling around the 2.4-mile-circumference RHIC collider crashed into a foil made of gold placed inside the STAR detector. That low energy gives scientists access to the highest baryon density, a measure related to the pressure generated in the collisions.

At this lowest collision energy, where the matter created in the collision is very dense, nuclei and hypernuclei are produced more abundantly than at higher collision energies, said Yue-Hang Leung, a postdoctoral fellow from the University of Heidelberg, Germany. The low-energy collisions are the only ones that produce enough of these particles to give us the statistics we need to do the analysis. Nobody else has ever done this before.

How does what the scientists learned at RHIC relate to neutron stars?

The fact that hypernuclei appear to form via coalescence just like ordinary nuclei implies that they, like those ordinary nuclei, are created at a late stage of evolution of the collision system.

At this late stage, the density for the hyperon-nucleon interaction we see is not that high, Dong said. So, these experiments may not be directly simulating the environment of a neutron star.

But, he added, This data is fresh. We need our theory friends to weigh in. And they need to include this new data on hyperon-nucleon interactions when they build a new neutron star model. We need both experimentalists and our theorists efforts to work towards understanding this data and making those connections.

Reference: Observation of Directed Flow of Hypernuclei 3H and 4H in sNN=3GeV Au+Au Collisions at RHIC by B.E. Aboona et al. (STAR Collaboration), 24 May 2023, Physical Review Letters.
DOI: 10.1103/PhysRevLett.130.212301

This research was funded by the DOE Office of Science (NP), the U.S. National Science Foundation, and a range of international organizations and agencies listed in the scientific paper. The STAR team used computing resources at the Scientific Data and Computing Center at Brookhaven Lab, the National Energy Research Scientific Computing Center (NERSC) at DOEs Lawrence Berkeley National Laboratory, and the Open Science Grid consortium.


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