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A NASA mission has observed a supermassive black hole pointing its highly energetic jet straight toward Earth. Don't panic just yet, though. As fearsome as this cosmic event is, it's located at a very safe distance of about 400 million light-years away.
Actively feeding supermassive black holes, including the one at hand, are surrounded by swirling disks of matter called accretion disks which gradually feed them over time. Some of the material they don't swallow is then channeled toward their poles, where it's subsequently blasted out at near-light, or relativistic, speed. This creates highly energetic and extremely bright electromagnetic radiation. In some cases, like with NASA's latest muse, that jet is pointed straight at Earth. Those events are known as blazars.
This blazar, designated Markarian 421 and located in the constellation Ursa Major, was observed with NASA's Imaging X-ray Polarimetry Explorer (IXPE), which launched in December 2021. IXPE observes a property of magnetic fields called polarization, which refers to the fields' orientation. The polarization of the jet blasted out by Markarian 421 revealed a surprise for astronomers, showing that the part of the jet where particles are being accelerated is also home to a magnetic field with a helical structure.
Blazar jets can stretch across space for millions of light-years, but the mechanisms that launch them aren't yet well-understood. However, these new discoveries surrounding the jet of Markarian 421 could shed some light on this extreme cosmic phenomenon.
"Markarian 421 is an old friend for high-energy astronomers," lead researcher behind the discovery and Italian Space Agency astrophysicist, Laura Di Gesu, said in a statement. "We were sure the blazar would be a worthwhile target for IXPE, but its discoveries were beyond our best expectations, successfully demonstrating how X-ray polarimetry enriches our ability to probe the complex magnetic field geometry and particle acceleration in different regions of relativistic jets."
The twisted structure of blazar jets
The main reason jets of feeding supermassive black holes are so bright is that particles approaching the speed of light give off tremendous amounts of energy and behave according to the physics of Einstein’s theory of special relativity.
Blazar jets also get an extra boost to such brightness because their orientation towards us causes wavelengths of light associated with their jets to "bunch up," increasing both their frequencies and energies. This is similar to how sound waves from the siren of an approaching ambulance "bunch up" to cause an increase in frequency that makes it sound more high-pitched.
As a result of these two effects, blazars can often outshine the combined light of every star in the galaxies that house them. And now, IXPE has used that light to paint a picture of the physics going on at the heart of Markarian 421's jet and even identify the glowing beam's point of origin.
Previously, models of blazar jets had hinted that they're accompanied by helical magnetic fields, almost like DNA in living cells, except single- rather than double-stranded. What wasn’t predicted, however, was the fact that the magnetic helix would host areas where particles are being accelerated.
"We had anticipated that the polarization direction might change, but we thought large rotations would be rare, based on previous optical observations of many blazars,” research co-author and Massachusetts Institute of Technology physicist, Herman Marshal, said. "So, we planned several observations of the blazar, with the first showing a constant polarization of 15%."
Even more remarkably, analysis of IXPE's data showed that the polarization of the jet dropped to 0% between its first and second observations. This showed the team the magnetic field was turning like a corkscrew.
"We recognized that the polarization was actually about the same but its direction literally pulled a U-turn, rotating nearly 180 degrees in two days," Marshall said. "It then surprised us again during the third observation, which started a day later, to observe the direction of polarization continuing to rotate at the same rate."
During these maneuvers, measurements of electromagnetic radiation in the form of optical, infrared and radio light showed no effect on the stability and structure of the jet itself, even when X-ray emissions did change. This implied a shockwave traveling along the twisted magnetic field from Markarian 421.
Hints of such a phenomenon have once been seen in the jet of another blazar witnessed by IXPE, Markarian 501, but the team's new findings represent more clearcut evidence that a helical magnetic field does indeed contribute to a traveling shockwave that's accelerating jet particles to relativistic speeds.
The team behind the work intends to continue studying Markarian 421 as well as identify other blazars to find some with similar qualities in pursuit of revealing a mechanism that powers the extreme and bright outflows characteristic of these phenomena.
"Thanks to IXPE, it's an exciting time for studies of astrophysical jets," Di Gesu concluded.
The team"s research was published on Monday (July 17) in the journal Nature Astronomy.
Originally posted on Space.com.
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Robert Lea is a science journalist in the U.K. who specializes in science, space, physics, astronomy, astrophysics, cosmology, quantum mechanics and technology. Rob's articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University
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Cosmology & The Universe
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An observation of a planetary nebula from the NIRCam instrument of NASA's James Webb Space Telescope, a revolutionary apparatus designed to peer through the cosmos to the dawn of the universe and released July 12, 2022. NASA, ESA, CSA, STScI, Webb ERO Production Team/Handout via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY.Register now for FREE unlimited access to Reuters.comGREENBELT, Md., July 13 (Reuters) - The powerful James Webb Space Telescope's inaugural batch of images has opened a new chapter of cosmic exploration, but astronomers say the observatory's most consequential discoveries may well be those they have yet to even imagine.Distant colliding galaxies, gas-giant exoplanets and dying star systems were the first celestial subjects captured by the multibillion-dollar observatory, putting its wide range of infrared-imaging capabilities on colorful display and proving the telescope works as designed. read more Webb's gallery of early photos and spectrographic data, which astronomers likened to the results of mere "target practice" as they readied the telescope for operational science, also previewed several planned areas of inquiry ahead.Register now for FREE unlimited access to Reuters.comThe competitively-selected agenda of research includes exploring the evolution of early galaxies, the life cycle of stars, the search for habitable planets orbiting distant suns, and the composition of moons in our own outer solar system.But the most revolutionary findings by Webb, 100 times more sensitive than its 30-year-old predecessor, the still-operational Hubble Space Telescope, may turn out to be accidental discoveries or answers to questions astronomers have yet to ask."Who knows what's coming for JWST. But I'm sure we're going to have a lot of surprises," René Doyon, principal investigator for one of Webb's instruments, the Near-Infrared Imager and Slitless Spectrograph, said Tuesday at NASA's Goddard Space Flight Center in Maryland, where the agency unveiled the observatory's first full-color images.With Webb open for business seven months after its launch in December, astronomers are preparing for "something that's out there that we never guessed would be there at all," said John Mather, a Nobel Prize-winning senior astrophysicist at NASA whose work during the 1990s helped cement cosmology's 'Big Bang' theory.DARK MATTER, DARK ENERGYMather and other scientists pointed to dark matter, an invisible and little-understood but theoretically influential cosmic scaffolding, as an enigma that Webb might unlock during its mission.Hubble, likewise, opened a whole new field of astrophysics devoted to another mysterious phenomenon, dark energy, as its observations of supernovas led to the unexpected discovery that the universe's expansion is accelerating.Taken together, dark energy and dark matter are now estimated by scientists to account for 95% of the known universe. All the galaxies, planets, dust, gases and other visible matter in the cosmos compose just 5%."Those were huge surprises," Mather said of early dark matter and dark energy discoveries.Amber Straughn, a deputy project scientist working with Webb, said: "It's hard to imagine what we might learn with this hundred-times-more-powerful instrument that we really don't know yet."Dark matter already has figured prominently in Webb's very first "deep field" image, a composite photo of a distant galaxy cluster, SMACS 0723, that offers the most detailed glimpse to date of the early universe thanks to a magnifying effect called a gravitational lens.The sheer combined mass of galaxies and other unseen matter in the foreground of the image warps the surrounding space enough to amplify light coming from more distant galaxies behind them, bringing into view fainter objects farther away, and thus further back in time.At least one of the tiny specks of light "photo-bombing" the edge of the picture dates back 13.1 billion years, or nearly 95% of the way to the Big Bang, the theoretical cosmic flashpoint that put the universe in motion 13.8 billion years ago.But because the calculated combined mass of all the visible matter in the foreground is insufficient by itself to produce the faint circular distortion seen in the image, the lensing effect is firm indirect evidence of dark matter's presence."It's the most powerful tool that we have, astrophysically, to do this type of lensing experiment," said Jane Rigby, a Webb operations project scientist. "We can't directly detect dark matter, but we see its impact... we can see its effects in action.""The universe has been out there, we just had to build a telescope to see what was there," she added.New light was also shed unexpectedly from Webb's first spectrographic analysis of an exoplanet in a distant solar system, in this case a gas giant roughly the size of Jupiter dubbed WASP-96 b.Measuring the wavelengths from light filtered through the atmosphere of the exoplanet as it orbited its own sun clearly revealed the molecular signature of water vapor in clouds and haze, features scientists were surprised to find."There are discoveries in these data," Webb program scientist Eric Smith said. "We're making discoveries and we really haven't even started trying yet."Register now for FREE unlimited access to Reuters.comReporting by Joey Roulette in Greenbelt, Md.; Additional reporting and editing by Steve Gorman; Editing by Rosalba O'BrienOur Standards: The Thomson Reuters Trust Principles.
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Cosmology & The Universe
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Using data from the James Webb Space Telescope's first year of interstellar observation, an international team of researchers was able to serendipitously view an exploding supernova in a faraway spiral galaxy.
The study, published recently in The Astrophysical Journal Letters, provides new infrared measurements of one of the brightest galaxies in our cosmic neighborhood, NGC 1566, also known as the Spanish Dancer. Located about 40 million miles away from Earth, the galaxy's extremely active center has led it to become especially popular with scientists aiming to learn more about how star-forming nebulae form and evolve.
In this case, scientists were able to survey a Type 1a supernova -- the explosion of a carbon-oxygen white dwarf star, which Michael Tucker, a fellow at the Center for Cosmology and AstroParticle Physics at The Ohio State University and a co-author of the study, said researchers caught by mere chance while studying NGC 1566.
"White dwarf explosions are important to the field of cosmology, as astronomers often use them as indicators of distance," said Tucker. "They also produce a huge chunk of the iron group elements in the universe, such as iron, cobalt and nickel."
The research was made possible thanks to the PHANGS-JWST Survey, which, due to its vast inventory of star cluster measurements, was used to create a reference dataset to study in nearby galaxies. By analyzing images taken of the supernova's core, Tucker and co-author Ness Mayker Chen, a graduate student in astronomy at Ohio State who led the study, aimed to investigate how certain chemical elements are emitted into the surrounding cosmos after an explosion.
For instance, light elements like hydrogen and helium were formed during the big bang, but heavier elements can be created only through the thermonuclear reactions that happen inside supernovas. Understanding how these stellar reactions affect the distribution of iron elements around the cosmos could give researchers deeper insight into the chemical formation of the universe, said Tucker.
"As a supernova explodes, it expands, and as it does so, we can essentially see different layers of the ejecta, which allows us to probe the nebula's core," he said. Powered by a process called radioactive decay -- wherein an unstable atom releases energy to become more stable -- supernovas emit radioactive high-energy photons like uranium-238. In this instance, the study specifically focused on how the isotope cobalt-56 decays into iron-56.
Using data from JWST's near-infrared and mid-infrared camera instruments to investigate the evolution of these emissions, researchers found that more than 200 days after the initial event, supernova ejecta was still visible at infrared wavelengths that would have been impossible to image from the ground.
"This is one of those studies where if our results weren't what we expected, it would have been really concerning," he said. "We've always made the assumption that energy doesn't escape the ejecta, but until JWST, it was only a theory."
For many years, it was unclear whether fast-moving particles produced when cobalt-56 decays into iron-56 seeped into the surrounding environment, or were held back by the magnetic fields supernovas create.
Yet by providing new insight into the cooling properties of supernova ejecta, the study confirms that in most circumstances, ejecta doesn't escape the confines of the explosion. This reaffirms many of the assumptions scientists have made in the past about how these complex entities work, Tucker said.
"This study validates almost 20 years' worth of science," he said. "It doesn't answer every question, but it does a good job of at least showing that our assumptions haven't been catastrophically wrong."
Future JWST observations will continue to help scientists develop their theories about star formation and evolution, but Tucker said that further access to other types of imaging filters could help test them as well, creating more opportunities to understand wonders far beyond the edges of our own galaxy.
"The power of JWST is really unparalleled," said Tucker. "It's really promising that we're accomplishing this kind of science and with JWST, there's a good chance we'll not only be able to do the same for different kinds of supernovas, but do it even better."
This work was supported by the National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, and others.
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Cosmology & The Universe
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A European Space Agency telescope launched Saturday on top of a SpaceX Falcon 9 rocket from Florida to begin a $1.5 billion mission seeking to answer fundamental questions about the unseen forces driving the expansion of the Universe. The Euclid telescope, named for the ancient Greek mathematician, will observe billions of galaxies during its six-year survey of the sky, measuring their shapes and positions going back 10 billion years, more than 70 percent of cosmic history.
Led by the European Space Agency, the Euclid mission has the ambitious goal of helping astronomers and cosmologists learn about the properties and influence of dark matter and dark energy, which are thought to make up about 95 percent of the Universe. The rest of the cosmos is made of regular atoms and molecules that we can see and touch.
Stumbling in the dark
“To highlight the challenge we face, I would like to give the analogy: It’s very difficult to find a black cat in a dark room, especially if there’s no cat,” said Henk Hoekstra, a professor and cosmologist at Leiden Observatory in the Netherlands. “That’s a little bit of the situation we find ourselves in because we have these observations … But we lack a good theory. So far, nobody has come up with a good explanation for dark matter or dark energy.”
Hoekstra, who is part of the consortium of international scientists eager to work with Euclid data, said the launch is a “very special day.”
“The launch of Euclid really changes cosmology into the future,” he said. “It’s the first space mission designed to study dark energy.”
But Euclid will also provide a test of Einstein’s theory of relativity and long-standing astrophysical models on cosmic scales. “Maybe we’re completely wrong,” Hoekstra said. “We have to keep it in the back of our mind that maybe gravity is wrong when we apply it to the whole cosmos.”
The spacecraft measures about 15.4 feet (4.7 meters) tall and carries a 600-megapixel visible light camera and a 64-megapixel near-infrared imager and spectrometer, which contains detectors provided by NASA. Euclid is expected to downlink about 100 gigabytes of compressed data every day, and over the course of its mission, will produce about 170 petabytes of information after automated processing at nine ground-based data centers.
“The required amount of data that will be analyzed and delivered back, the numbers are absolutely staggering,” said Gaitee Hussain, head of the science division at the European Space Agency. “This is what is required in order to answer what is arguably the most fundamental question in physics and cosmology today, which is what is the Universe actually made of?”
After more than 15 years of design, development, and testing, the Euclid telescope lifted off from Cape Canaveral at 11:12 am EDT (1512 UTC) aboard a Falcon 9 rocket. The launcher arced downrange heading southeast from the Florida coastline, with nine kerosene-fueled engines powering the Falcon 9 through the atmosphere in the first two-and-a-half minutes of the flight.
The rocket’s reusable booster stage released to begin a descent to a drone ship parked in the Atlantic Ocean, while the upper stage ignited its engine two times to propel the roughly 2.1-ton Euclid spacecraft onto a trajectory toward an orbit about a million miles (1.5 million kilometers) from Earth.
It will take about a month for Euclid to cruise into its halo orbit around the Sun-Earth L2 Lagrange point, a gravitational balance point commonly used by space-based observatories, including the James Webb Space Telescope.
Following three months of checkouts, first light, and calibration, Euclid should be ready to start its operational science mission in October. The telescope will scan about 15,000 square degrees of the sky with its visible and infrared instruments, primarily in the northern and southern sky, while avoiding brighter regions populated with light from our own galaxy and Solar System.
Euclid to solve 'biggest embarrassment' in cosmology
Dark matter has never been directly measured, but scientists have concluded that it makes up a little more than a quarter of the Universe. Dark energy, on the other hand, constitutes about 70 percent of the cosmos, and according to models, is responsible for accelerating the Universe’s expansion.
Guadalupe Cañas, a research fellow at ESA, called the vacuum in understanding the nature of dark matter and dark energy the “biggest embarrassment that we have currently in cosmology.”
“We know that 95 percent of our Universe is something that is totally unknown to us,” she said.
Euclid’s 3.9-foot (1.2-meter) telescope is about half the size of the primary mirror of the Hubble Space Telescope, or little less than one-fifth that of the James Webb Space Telescope. While that means Euclid won’t be able to study galaxies as old as Hubble or Webb can see, Euclid has the benefit of seeing a broader swath of the sky. Think of it as trading a telephoto lens for a wide-angle. “If you want to observe the Universe in a cosmological way, you don’t want to be restricted to particular areas,” said Giuseppe Racca, ESA’s Euclid project manager. “You really want to observe a lot.”
Scientists say it would take Hubble hundreds of years to complete the same extra-galactic survey as Euclid, which will cover in a week the same area of sky that Hubble has observed in its 33-year mission.
After an initial period of cosmic expansion after the Big Bang (known as inflation), the Universe’s growth decelerated until about five to six billion years ago. Cosmologists have found that the expansion of the Universe started accelerating at this point. Euclid’s observations will cover the period of time before and after the start of the acceleration.
Euclid will pursue signs of dark matter and dark energy using two methods.
One is called weak gravitational lensing, where astronomers will rely on automated processing to detect minute changes in the shape of galaxies caused by clumps of invisible dark matter on the line of sight between the Euclid telescope and its distant targets.
Distortions in the shapes of faraway galaxies are easily observable in close-up views taken by Hubble and Webb, but there should also be subtle effects from dark matter—at least that’s what scientists think.
“Everything looks normal, but when you do the statistics of those, you will find that actually, on average, these galaxies have acquired a net preferred direction (due to dark matter). It’s just extremely noisy,” Hoekstra said. “So this is why, with Euclid, we need one-and-a-half billion galaxies to really beat down the noise because, unfortunately, galaxies are not nice and round. If they were nice and round, we could do an amazing measurement, but galaxies have all kinds of shapes and sizes and that’s why we need all this data.”
Euclid will also help cosmologists study how barely perceptible fluctuations in sound energy in the early Universe, called baryon acoustic oscillations, led to the patterns of galaxy formation and clustering that spread throughout the cosmos over billions of years.
Ultimately, scientists will compare what they learn from Euclid with their expectations based on model predictions.
“If these predictions, to a certain accuracy, are not fulfilled, then we have something new in hand,” said René Laureijs, Euclid project scientist at ESA. “Then we can say Euclid is so precise that the predictions we have at the moment cannot be reconciled with our observations, and then we have maybe something new in hand, in terms of physics.”
SpaceX steps in to launch European space missions
The Euclid mission was originally slated to launch on a Russian Soyuz rocket from the European spaceport in French Guiana, but that option became unavailable after Russia’s invasion of Ukraine.
Euclid was already built and well into its final round of pre-launch testing when ESA had to search for a new launch vehicle. The backup option, a European Ariane 6 rocket, is still in development after years of delays.
That forced ESA to look overseas. Enter SpaceX.
European officials started discussions with SpaceX about one year ago, and ESA member states approved the switch to a foreign rocket—a thought that is anathema to ESA’s “buy European” policies—in October. Otherwise, Euclid would likely have remained grounded until at least 2025, when officials hope the new Ariane 6 will be flying and will have reached a level of reliability required to launch such a costly mission, said Mike Healy, ESA’s head of science projects.
SpaceX and ESA agreed on a contract to launch Euclid last December, and the little more than six months before the target liftoff date. At that time, officials hoped to launch Euclid at the beginning of July. It turned out that Euclid launched right on time, despite an "incredibly tense" period when there was uncertainty about how and when the mission might get into space, Racca said.
Engineers performed additional checks to ensure Euclid’s sensitive optics and telescope made of silicon carbide—which combine the properties of metal and ceramics—could withstand the stronger vibrations of SpaceX’s rocket.
SpaceX charged ESA about $70 million to launch Euclid, according to Healy. That’s about $5 million above the standard commercial “list price” for a dedicated Falcon 9 launch, covering extra costs for SpaceX to meet unusually stringent cleanliness requirements for the Euclid telescope. A grain of dust or a piece of hair on the telescope’s optics could ruin the mission.
SpaceX also provided a brand new payload fairing for the Euclid mission to reduce the risk of any contaminants falling onto the telescope. Most launches employ a payload shroud reused from previous missions.
Delays in the Ariane 6 rocket has also prompted ESA to agree to launch the agency’s Hera asteroid probe on a Falcon 9 rocket from Cape Canaveral in 2024. Earlier this week, ESA’s director general said an Earth science satellite called EarthCARE will also have to launch on a SpaceX Falcon 9 rocket due to problems with its European Vega C rocket.
And ESA, along with the European Union, is considering launching up to four Galileo navigation satellites on two SpaceX Falcon 9 rockets because European launchers are not ready.
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Cosmology & The Universe
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SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer), a space observatory by NASA designed to explore the origin of the universe, galaxies, and water in planetary systems. Credit: NASA Jet Propulsion Laboratory, Public domain, via Wikimedia Commons. The cosmic optical background (COB) is the visible light emitted by all sources outside of the Milky Way. This faint glow of light, which can only be observed using very precise and sophisticated telescopes, could help astrophysics to learn more about the origins of the universe and what lies beyond our galaxy. Last year, physicists working at different institutes across the United States published the most precise COB measurements collected so far, gathered by the New Horizons spacecraft, an interplanetary space probe launched by NASA over a decade ago. These measurements suggested that the COB is two times brighter than theoretical predictions. Researchers at Johns Hopkins University have recently carried out a theoretical study exploring the possibility that this observed excess light could be caused by the decay of a hypothesized type of dark matter particles, known as axions. In their paper, published in Physical Review Letters, they showed that axions with masses between 8 and 20 eV could potentially account for the excess COB flux measured by the New Horizons team.
"Marc Postman is a colleague across the street who is an incredible observational cosmologist, and so when his paper with Todd Lauer and the New Horizons team appeared, I noticed it and read it," Marc Kamionkowski, one of the researchers who carried out the study, told Phys.org. "The measurement they collected is a great example of cleverly repurposing a powerful astronomical observatory to different ends than those it was designed for. We sent this incredible little spacecraft out toward Pluto years ago, and it did everything it was supposed to, but it had no brakes, and is still speeding further and further from the sun with not much to do. Marc and Todd realized that it could be used to detect—for the very first time—the cosmic background of optical photons from all the unresolved galaxies in the universe, and it did." The Feynman diagram for the decay of an axion to two photons. The particles in the loops include all charged leptons and quarks. Credit: Caltech (https://ned.ipac.caltech.edu/level5/March06/Overduin/Overduin6.html). After reading the paper by Lauer and his colleagues, Kamionkowski realized that if the excess they measured was in-fact attributed to the decay of axions, this could be potentially confirmed using available cosmological data. Specifically, this excess would be detected with a high signal-to-noise ratio during SPHEREx, a planned two-year NASA mission that will send a near-infrared space observatory into space to collect new and potentially valuable measurements. "Our calculations are embarrassingly simple, as they are the types of calculations that we and tons of other people have been doing for years," Kamionkowski explained. "The idea that two-photon decay of an axion could lead to a cosmic signal was already around when I was a graduate student over 30 years ago. Our work simply involves summing the photons from all those produced by axion decay over time, a simple integral. We had to get some factors of cosmic redshift in there correctly, but that's a homework problem in a typical cosmology class."
Overall, the calculations performed by Kamionkowski and his colleagues highlight the possibility of confirming or disproving the connection between axion dark matter decay and the recently observed excess COB using future line-intensity-mapping (LIM) measurements set to be collected by NASA's SPHEREx satellite. SPHEREx is expected to launch in 2025, collecting measuring near-infrared signals originating from approximately 450 million galaxies. The researchers at Johns Hopkins have already published a follow-up paper, where they explored the consistency of the axion decay scenario with existing constraints to COB from gamma rays.
"NASA's Fermi telescope has obtained gamma-ray energy spectra from over 800 blazars, and the highest-energy gamma rays can be attenuated by production of electron-positron pairs via scattering with COB photons," Kamionkowski added. "In our new study, we modeled the attenuation expected from this COB scattering and by comparing with Fermi data were able to place an upper limit to the COB background from dark-matter decay, which was still consistent with the COB excess inferred from New Horizons. "My student Gabriela Sato-Polito has also been working with Dan Grin (Haverford College) looking in deep VLT images of several high-redshift clusters for dark-matter decay lines. These measurements should allow us to probe some, but not all, of the parameter space for dark-matter decays consistent with the New Horizons excess." More information: José Luis Bernal et al, Cosmic Optical Background Excess, Dark Matter, and Line-Intensity Mapping, Physical Review Letters (2022). DOI: 10.1103/PhysRevLett.129.231301
Tod R. Lauer et al, New Horizons Observations of the Cosmic Optical Background, The Astrophysical Journal (2021). DOI: 10.3847/1538-4357/abc881
José Luis Bernal et al, Seeking dark matter with γ-ray attenuation, arXiv (2022). DOI: 10.48550/arxiv.2208.13794 © 2022 Science X Network Citation: Could axion decay underlie excess cosmic optical background? (2022, December 14) retrieved 15 December 2022 from https://phys.org/news/2022-12-axion-decay-underlie-excess-cosmic.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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Cosmology & The Universe
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NEWYou can now listen to Fox News articles! Astronomers at the Massachusetts Institute of Technology (MIT) and universities in Canada and the U.S. say they have detected a radio signal from a far-away galaxy that is flashing repetitively. In research published in the Journal Nature, authored by members of the Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB Collaboration, the scientists said a fast radio burst (FRB) has been located several billion light-years from Earth. CHIME is an interferometric radio telescope at the Dominion Radio Astrophysical Observatory in British Columbia, Canada. It is designed to detect radio waves emitted by hydrogen in the earliest stages of the universe, and it has detected hundreds of FRBs.FRBs are millisecond-duration flashes of radio waves that are visible at distances of billions of light-years. The first FRB was discovered 15 years ago; hundreds of similar radio flashes have been detected, although the majority of observed FRBs have been one-offs.NASA, PARTNERS REVEAL STUNNINGLY-DETAILED FIRST IMAGES FROM JAMES WEBB SPACE TELESCOPE Star formed of compressed Neutron star, Star formed of compressed.neutrons, believed to be the residue of a supernova explosion. (Photo by: QAI Publishing/Universal Images Group via Getty Images)Exactly what the source of the FRB is, labeled FRB 20191221A, remains a mystery. Astronomers theorize that the repeating signal could be coming from either a magnetar or radio pulsar – types of neutron stars – "on steroids." Neutron stars are dense, spinning collapsed cores of giant stars.However, it's the duration of FRB 20191221A that's most notable. The radio signal, which was picked up in December 2019, lasts for up to three seconds, or about 1,000 times longer than the average FRB. "It was unusual," Daniele Michilli, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research, recalled in a statement. "Not only was it very long, lasting about three seconds, but there were periodic peaks that were remarkably precise, emitting every fraction of a second — boom, boom, boom — like a heartbeat. This is the first time the signal itself is periodic."FULL BUCK SUPERMOON CAPTURED AROUND GLOBEIt is currently the longest-persisting FRB with the clearest periodic pattern thus far and the team detected bursts of radio waves that repeat every 0.2 seconds in a clear pattern."The long (roughly [3-second]) duration and nine or more components forming the pulse profile make this source an outlier in the FRB population. Such short periodicity provides strong evidence for a neutron-star origin of the event. Moreover, our detection favors emission arising from the neutron-star magnetosphere, as opposed to emission regions located further away from the star, as predicted by some models," the group wrote.In addition, FRB 20191221A appears to be more than a million times brighter than radio emissions from our own galactic pulsars and magnetars. A composite image of the Cosmic Cliffs in the Carina Nebula, created with NIRCam and MIRI instrument data from NASA's James Webb Space Telescope, a revolutionary apparatus designed to peer through the cosmos to the dawn of the universe and released July 12, 2022. (NASA, ESA, CSA, STScI, Webb ERO Production Team/Handout via REUTERS)"CHIME has now detected many FRBs with different properties," Michilli noted. "We’ve seen some that live inside clouds that are very turbulent, while others look like they’re in clean environments. From the properties of this new signal, we can say that around this source, there’s a cloud of plasma that must be extremely turbulent."The team aims to detect more signals from this source, which MIT said in a release could be used as an "astrophysical clock" – perhaps even measuring the rate at which the universe is expanding. CLICK HERE TO GET THE FOX NEWS APPMichilli said future telescopes promise to discover thousands of FRBs a month, which could lead to the detection of "many more of these periodic signals." This announcement follows the release of the first images from the James Webb Space Telescope, which peers back billions of years ago. Julia Musto is a reporter for Fox News Digital. You can find her on Twitter at @JuliaElenaMusto.
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Cosmology & The Universe
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The James Webb Space Telescope has captured the "signature of water" and evidence of clouds and haze on a giant gas planet orbiting a distant sunlike star 1,150 light-years away. The observation comes with the release of the first five full-color images from the telescope by NASA, the European Space Agency, and the Canadian Space Agency on Tuesday, hailed as the "deepest" and sharpest infrared images of the universe ever produced. FIRST FULL-COLOR IMAGE FROM JAMES WEBB SPACE TELESCOPE REVEALED NASA's Hubble Space Telescope, Webb's predecessor, was the first to capture the detection of water in 2013, though NASA said Webb's observation was "more detailed" and "immediate." "Researchers will be able to use the spectrum to measure the amount of water vapor in the atmosphere, constrain the abundance of various elements like carbon and oxygen, and estimate the temperature of the atmosphere with depth," NASA said. "They can then use this information to make inferences about the overall make-up of the planet, as well as how, when, and where it formed." The first images centered on five cosmic targets, including the Carina Nebula, "the earliest, rapid phases of star formation that were previously hidden"; the Southern Ring Nebula, an expanding cloud of gas surrounding a dying star; Stephan’s Quintet, a galaxy cluster; the WASP-96b exoplanet, located 1,150 light-years from Earth; and SMACS 0723. "Today, we present humanity with a groundbreaking new view of the cosmos from the James Webb Space Telescope — a view the world has never seen before,” NASA Administrator Bill Nelson said Tuesday. “These images, including the deepest infrared view of our universe that has ever been taken, show us how Webb will help to uncover the answers to questions we don’t even yet know to ask; questions that will help us better understand our universe and humanity’s place within it." On Monday, President Joe Biden and Vice President Kamala Harris unveiled the first image captured by the telescope of "galaxy cluster SMACS 0723." Using infrared light, the telescope can see through cosmic dust, allowing scientists to see the first galaxies and stars to form in the universe. The telescope, developed by NASA and Northrop Grumman, is the largest and most powerful space telescope ever built, costing nearly $10 billion dollars and taking over 20 years to assemble. It was launched into space in December 2021 after a series of delays. CLICK HERE TO READ MORE FROM THE WASHINGTON EXAMINER Earlier this year, test images from the telescope, including its first "selfie" from space, were released while it was still in its commissioning phase, according to CNN.
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Cosmology & The Universe
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Just as Charles Darwin once used the fossil record to tell the story of the evolution of life on Earth, astronomers are using the first light ever to shine through the universe to understand events that have shaped the cosmos.
This first light is called the "Cosmic Microwave Background (CMB)," leftover radiation which is spread almost evenly through the universe. The CMB carries with it the signatures of the physical processes of the early universe and possesses unique features that can be used to determine the make-up of the universe.
Just like how the study of biological evolution has evolved since the time of Darwin, the ways in which cosmologists use this cosmic fossil have changed, and future missions are set to increase the focus on the CMB and what it can teach us about how the universe evolved.
On Monday, July 2, at the National Astronomy Meeting 2023 (NAM 2023) held at Cardiff University in the U.K., astrophysicist Erminia Calabrese offered overviews of both where CMB science is currently and where it is headed in the near future.
"The reason why this light has been really the driving force of modern cosmology is that it has been there throughout the whole of cosmic history," Calabrese said. "It was there from the beginning, it went through everything that the universe experienced. It traveled across the formation of the first stars, the forming and evolving large-scale structure of the universe.
"While taking this journey towards us, it has basically captured imprints from all these physics, and carries it with it when it today."
Let there be light: What is the Cosmic Microwave Background?
If you could journey back around 380,000 years in cosmic history to the point at which the universe was filled with a dense hot soup of electrons and protons, the first thing you would notice is how dark the cosmos is.
The reason this early epoch in the 13.8 billion-year history of the universe is a literal cosmic dark age is because the abundance of free electrons meant that photons, particles of light, were endlessly scattered, thus preventing them from traveling. At this time, the universe was essentially opaque to light.
"So what we are looking at is the very first light ever emitted in the universe, composed of photons that were emitted during the Big Bang," Calabrese explained. "The photons were trapped in interactions with everything else, meaning any particle phenomenon that was happening in this very hot and dense phase of the universe was interacting with these photons."
That means as they were trapped, the photons were creating a record of the physics in the early universe, but they couldn't stay trapped and in equilibrium with matter forever.
Eventually, undergoing rapid cosmic inflation as a result of the Big Bang, the universe expanded and cooled enough to allow electrons to bond with protons and form the first neutral atoms. This is known as the period of recombination, even though electrons and protons had not been previously connected.
Initially, the light that comprises the CMB was incredibly hot and energetic, but as the universe continued to expand it has cooled and lost energy, which has seen the frequency of this radiation reduced to the microwave region of the electromagnetic spectrum.
Calabrese explains that currently, the CMB takes the form of a radiation field with a temperature of 2.7 Kelvin (-455 degrees Fahrenheit or -270.4 degrees Celsius).
How do scientists use the Cosmic Microwave Background?
Because recombination happened all over the universe at the same time, CMB radiation streams to us from all directions evenly. That means that this cosmic fossil looks the same in all areas of the sky — which scientists describe as being isotropic.
This sameness, even at opposite sides of the universe in areas not currently in contact, is one of the key pieces of evidence that the universe once existed in a hot and dense state and then underwent a period of rapid inflation, which we now call the Big Bang. But it is in the areas where tiny differences arise that scientists find a useful cosmic fossil record.
Within the CMB are small deviations from this uniformity called anisotropies. It is through these anisotropies that the CMB contains information about the evolution of the universe.
Small-scale anisotropies in the CMB represent tiny fluctuations in density in the early universe that eventually resulted in the creation of galaxies and galaxy clusters. Though they may be tiny, without these variations, the large-scale structure we see in the universe today couldn't have taken shape.
It is larger anisotropies that reveal the contents of the universe and the abundance of these elements throughout cosmic history. This includes not just visible "everyday" matter comprised of atoms and constituting stars, planets, cosmic gas clouds, and us, but also invisible dark matter and dark energy, the forces that are driving the current day accelerating expansion of the universe.
"In particular, there are three methods we work with to study the CMB: We can go to space, and we've had three different generations of satellites that have been dedicated to measuring the CMB anisotropies," Calabrese explained. "You can stay on Earth but try to get higher in the atmosphere with stratospheric balloons, or you just stay on the ground and then deal with the atmosphere. All these methods have got pros and cons; no single experiment can give you access to everything."
In Calabrese's NAM 2023 talk, the researcher highlighted the need for future CMB studying missions that could answer fundamental questions such as what is dark matter made of and what is the large-scale distribution of mass in the universe.
One such mission mentioned by Calabrese is the Japanese Aerospace Exploration Agency (JAXA) mission known as the Space Lite (Light) satellite for the study of B-mode polarization and Inflation from cosmic background Radiation Detection (LiteBIRD).
LiteBIRD will observe the entire sky for three years from orbit, and JAXA says it will achieve unprecedented sensitivity, allowing it to precisely distinguish between the CMB and foreground radiation signals from sources like cosmic dust. That means that LiteBIRD, set to launch in 2028, could help fill in the gaps in cosmic evolution that current Big Bang models can't explain.
"We really don't have answers to the big key fundamental questions that we were aiming to answer with CMB temperature, and now we need to take the next step and continue exploring and exploiting everything that is in the CMB to be able to answer them," Calabrese said.
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Cosmology & The Universe
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A filament of 10 galaxies seen just 830 million years after the birth of the universe.
Woven across our universe is a weblike structure of galaxies called the cosmic web. Galaxies are strung along filaments in this vast web, which also contains enormous voids. Now, astronomers using Webb have discovered an early strand of this structure, a long, narrow filament of 10 galaxies that existed just 830 million years after the big bang. The 3 million light-year-long structure is anchored by a luminous quasar – a galaxy with an active, supermassive black hole at its core. The team believes this early thread of the cosmic web will eventually evolve into a massive cluster of galaxies.
The same study also probes the properties of eight quasars in the young universe. Scientists determined that the galaxies’ central black holes, which existed less than a billion years after the big bang, range in mass from 600 million to 2 billion times that of our Sun. They are still working to explain how these black holes could grow so large so fast.
Webb Space Telescope Identifies the Earliest Strands of the Cosmic Web
Galaxies are not scattered randomly across the universe. They gather together not only into clusters, but into vast interconnected filamentary structures with gigantic barren voids in between. This “cosmic web” started out tenuous and became more distinct over time as gravity drew matter together.
Astronomers using NASA’s James Webb Space Telescope have discovered a thread-like arrangement of 10 galaxies that existed just 830 million years after the big bang. The 3 million light-year-long structure is anchored by a luminous quasar – a galaxy with an active, supermassive black hole at its core. The team believes the filament will eventually evolve into a massive cluster of galaxies, much like the well-known Coma Cluster in the nearby universe.
“I was surprised by how long and how narrow this filament is,” said team member Xiaohui Fan of the University of Arizona in Tucson. “I expected to find something, but I didn’t expect such a long, distinctly thin structure.”
“This is one of the earliest filamentary structures that people have ever found associated with a distant quasar,” added Feige Wang of the University of Arizona in Tucson, the principal investigator of this program.
This discovery is from the ASPIRE project (A SPectroscopic survey of biased halos In the Reionization Era), whose main goal is to study the cosmic environments of the earliest black holes. In total, the program will observe 25 quasars that existed within the first billion years after the big bang, a time known as the Epoch of Reionization.
“The last two decades of cosmology research have given us a robust understanding of how the cosmic web forms and evolves. ASPIRE aims to understand how to incorporate the emergence of the earliest massive black holes into our current story of the formation of cosmic structure,” explained team member Joseph Hennawi of the University of California, Santa Barbara.
Growing Monsters
Another part of the study investigates the properties of eight quasars in the young universe. The team confirmed that their central black holes, which existed less than a billion years after the big bang, range in mass from 600 million to 2 billion times the mass of our Sun. Astronomers continue seeking evidence to explain how these black holes could grow so large so fast.
“To form these supermassive black holes in such a short time, two criteria must be satisfied. First, you need to start growing from a massive ‘seed’ black hole. Second, even if this seed starts with a mass equivalent to a thousand Suns, it still needs to accrete a million times more matter at the maximum possible rate for its entire lifetime,” explained Wang.
“These unprecedented observations are providing important clues about how black holes are assembled. We have learned that these black holes are situated in massive young galaxies that provide the reservoir of fuel for their growth,” said Jinyi Yang of the University of Arizona, who is leading the study of black holes with ASPIRE.
Webb also provided the best evidence yet of how early supermassive black holes potentially regulate the formation of stars in their galaxies. While supermassive black holes accrete matter, they also can power tremendous outflows of material. These winds can extend far beyond the black hole itself, on a galactic scale, and can have a significant impact on the formation of stars.
“Strong winds from black holes can suppress the formation of stars in the host galaxy. Such winds have been observed in the nearby universe but have never been directly observed in the Epoch of Reionization,” said Yang. “The scale of the wind is related to the structure of the quasar. In the Webb observations, we are seeing that such winds existed in the early universe.”
These results were published in two papers in The Astrophysical Journal Letters on June 29.
References:
“A SPectroscopic Survey of Biased Halos in the Reionization Era (ASPIRE): JWST Reveals a Filamentary Structure around a z = 6.61 Quasar” by Feige Wang, Jinyi Yang, Joseph F. Hennawi, Xiaohui Fan, Fengwu Sun, Jaclyn B. Champagne, Tiago Costa, Melanie Habouzit, Ryan Endsley, Zihao Li, Xiaojing Lin, Romain A. Meyer, Jan–Torge Schindler, Yunjing Wu, Eduardo Bañados, Aaron J. Barth, Aklant K. Bhowmick, Rebekka Bieri, Laura Blecha, Sarah Bosman, Zheng Cai, Luis Colina, Thomas Connor, Frederick B. Davies, Roberto Decarli, Gisella De Rosa, Alyssa B. Drake, Eiichi Egami, Anna-Christina Eilers, Analis E. Evans, Emanuele Paolo Farina, Zoltan Haiman, Linhua Jiang, Xiangyu Jin, Hyunsung D. Jun, Koki Kakiichi, Yana Khusanova, Girish Kulkarni, Mingyu Li, Weizhe Liu, Federica Loiacono, Alessandro Lupi, Chiara Mazzucchelli, Masafusa Onoue, Maria A. Pudoka, Sofía Rojas-Ruiz, Yue Shen, Michael A. Strauss, Wei Leong Tee, Benny Trakhtenbrot, Maxime Trebitsch, Bram Venemans, Marta Volonteri, Fabian Walter, Zhang-Liang Xie, Minghao Yue, Haowen Zhang, Huanian Zhang and Siwei Zou, 29 June 2023, The Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/accd6f
“A SPectroscopic Survey of Biased Halos in the Reionization Era (ASPIRE): A First Look at the Rest-frame Optical Spectra of z > 6.5 Quasars Using JWST” by Jinyi Yang, Feige Wang, Xiaohui Fan, Joseph F. Hennawi, Aaron J. Barth, Eduardo Bañados, Fengwu Sun, Weizhe Liu, Zheng Cai, Linhua Jiang, Zihao Li, Masafusa Onoue, Jan-Torge Schindler, Yue Shen, Yunjing Wu, Aklant K. Bhowmick, Rebekka Bieri, Laura Blecha, Sarah Bosman, Jaclyn B. Champagne, Luis Colina, Thomas Connor, Tiago Costa, Frederick B. Davies, Roberto Decarli, Gisella De Rosa, Alyssa B. Drake, Eiichi Egami, Anna-Christina Eilers, Analis E. Evans, Emanuele Paolo Farina, Melanie Habouzit, Zoltan Haiman, Xiangyu Jin, Hyunsung D. Jun, Koki Kakiichi, Yana Khusanova, Girish Kulkarni, Federica Loiacono, Alessandro Lupi, Chiara Mazzucchelli, Zhiwei Pan, Sofía Rojas-Ruiz, Michael A. Strauss, Wei Leong Tee, Benny Trakhtenbrot, Maxime Trebitsch, Bram Venemans, Marianne Vestergaard, Marta Volonteri, Fabian Walter, Zhang-Liang Xie, Minghao Yue, Haowen Zhang, Huanian Zhang and Siwei Zou, 29 June 2023, The Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/acc9c8
The James Webb Space Telescope is the world’s premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency), and CSA (Canadian Space Agency).
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Cosmology & The Universe
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The world of astronomy mourned the recent passing of Dutch-American astronomer Maarten Schmidt, the first person to measure the distance to a quasar. His groundbreaking work in the 1960’s greatly expanded the size of the known universe, providing one of the first clues that the Big Bang theory was correct. Schmidt died on Sept. 17 at his home in Fresno, California. He was 92 years old. The story of quasars began several years before Schmidt focused his attention on them. Starting in the 1950s, astronomers identified several sources of radio emissions in the sky. Many of those radio sources could be assigned to known objects, like bright stars or nearby galaxies. But some remained frustratingly elusive, having no visible counterpart. Whatever these strange radio sources were, they appeared as point-like objects, indicating that they were either huge in size but incredibly far away or small and nearby.
Astronomers, never slow to assign a name to a new category of celestial phenomenon, quickly designated these radio sources “quasi-stellar objects,” which was shortened to quasars.
Unraveling the mysteries of quasars
Schmidt, who received his Doctor of Philosophy from Leiden University in 1956 under the tutelage of Dutch astronomer Jan Oort (of Oort Cloud fame), eventually moved to the California Institute of Technology to continue his studies into the properties and evolution of galaxies. Among Schmidt’s many accomplishments during his tenure there, he was the first to discover that the density of interstellar gas within galaxies was proportional to their rate of star formation, a relationship now known as the Schmidt law (or, more recently, the Kennicutt-Schmidt law).
Schmidt then turned his attention to finding the light spectra of radio sources, especially these mysterious quasars. By the early 1960s, astronomers had been able to identify optical light counterparts to one other quasar, but its spectrum remained poorly understood — its light output did not match any other known type of astronomical object.
In 1963, Schmidt used the 200-inch Hale telescope at Palomar Observatory to discover the optical counterpart of the quasar known as 3C 273, one of the first to be discovered. He also gathered the spectrum of this poorly understood object, and that spectrum featured strange emission lines that, once again, defied explanation.
After several weeks of deep contemplation and much nervous pacing around his home, Schmidt realized what he was looking at: a perfectly normal galaxy. All the emission lines from all the usual elements were there, like hydrogen and helium, but they were simply shifted far down toward the red end of the spectrum.
The light spectrum of an astronomical object can shift from two things. One is the Doppler effect: If an object is moving away from us, the wavelength of its emitted light will lengthen, and its emission lines will be redshifted. But the position of the emission lines from 3C 273 implied a recession velocity of around 100 million mph, some 15 percent the speed of light! This redshift result was orders of magnitude larger than that found for any other known object.
Quasars: The luminous cores of distant galaxies
Schmidt argued for another interpretation in his Nature paper describing his discovery: the Big Bang. Distant objects are pulled away from us due to the expansion of space itself, which also causes a redshift. It was this realization that allowed Edwin Hubble to lay the observational groundwork for the Big Bang theory in the 1920s. But besides Hubble’s insight, there was little more to anchor the Bang Bang in observations. And so astronomers continued to debate its validity.
Schmidt’s work showed that 3C 273 was billions of light-years away, making it the most distant astronomical object known at the time. This discovery of the first distance to a quasar dramatically rewrote our understanding of the true scale of the cosmos.
For quasars to be detectable at such vast distances, they must be insanely luminous. In fact, they must be the most luminous objects in the universe. Schmidt believed that when we observe a quasar, we are seeing the light emitted as gas violently swirls and grinds together around a gigantic black hole in a newly forming galaxy, which turned out to be the correct interpretation.
The existence of quasars provided proponents of the Big Bang theory a major observational win. Quasars only appear in the distant universe; there are no nearby objects like them. In the Big Bang model, the universe changes and evolves as it continues to cool and expand. And because quasars are only found far, far away, they must have only existed in the early universe, not our modern-day one. In 1966, Time magazine put Schmidt on their cover, likening his discovery of the true nature of quasars to those of Galileo’s in its power to reshape our understanding of the universe. And an accomplishment like that is sure to live on.
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Cosmology & The Universe
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Scientists find first evidence that black holes are the source of dark energy
Observations of supermassive black holes at the centers of galaxies point to a likely source of dark energy—the 'missing' 70% of the universe.
The measurements from ancient and dormant galaxies show black holes growing more than expected, aligning with a phenomenon predicted in Einstein's theory of gravity. The result potentially means nothing new has to be added to our picture of the universe to account for dark energy: black holes combined with Einstein's gravity are the source.
The conclusion was reached by a team of 17 researchers in nine countries, led by the University of Hawai'i and including Imperial College London and STFC RAL Space physicists. The work is published in two papers in the journals The Astrophysical Journal and The Astrophysical Journal Letters.
Study co-author Dr. Dave Clements, from the Department of Physics at Imperial, said, "This is a really surprising result. We started off looking at how black holes grow over time, and may have found the answer to one of the biggest problems in cosmology."
Study co-author Dr. Chris Pearson, from STFC RAL Space, said, "If the theory holds, then this is going to revolutionize the whole of cosmology, because at last we've got a solution for the origin of dark energy that's been perplexing cosmologists and theoretical physicists for more than 20 years."
Gravity versus dark energy
In the 1990s, it was discovered that the expansion of the universe is accelerating—everything is moving away from everything else at a faster and faster rate. This is difficult to explain—the pull of gravity between all objects in the universe should be slowing the expansion down.
To account for this, it was proposed that a 'dark energy' was responsible for pushing things apart more strongly than gravity. This was linked to a concept Einstein had proposed but later discarded—a 'cosmological constant' that opposed gravity and kept the universe from collapsing.
This concept was revived with the discovery of the accelerating expansion of the universe, with its main component being a kind of energy included in spacetime itself, called vacuum energy. This energy pushes the universe further apart, accelerating the expansion.
Black holes posed a problem though—their extremely strong gravity is hard to oppose, especially at their centers, where everything seems to break down in a phenomenon called a 'singularity.'
The new result shows that black holes gain mass in a way consistent with them containing vacuum energy, providing a source of dark energy and removing the need for singularities to form at their center.
Black hole growing pains
The conclusion was made by studying nine billion years of black hole evolution. Black holes are formed when massive stars come to the end of their life. When found at the centers of galaxies, they are called supermassive black holes. These contain millions to billions of times the mass of our Sun inside them in a comparatively small space, creating extremely strong gravity.
Black holes can increase in size by accreting matter, such as by swallowing stars that get too close, or by merging with other black holes. To discover whether these effects alone could account for the growth of supermassive black holes, the team looked at data spanning nine billion years.
The researchers looked at a particular type of galaxy called giant elliptical galaxies, which evolved early in the universe and then became dormant. Dormant galaxies have finished forming stars, leaving little material for the black hole at their center to accrete, meaning any further growth cannot be explained by these normal astrophysical processes.
Comparing observations of distant galaxies (when they were young) with local elliptical galaxies (which are old and dead) showed growth much larger than predicted by accretion or mergers: the black holes of today are 7—20 times larger than they were nine billion years ago.
Cosmological coupling
Further measurements with related populations of galaxies at different points in the universe's evolution show good agreement between the size of the universe and the mass of the black holes. These show that the measured amount of dark energy in the universe can be accounted for by black hole vacuum energy.
This is the first observational evidence that black holes actually contain vacuum energy and that they are 'coupled' to the expansion of the universe, increasing in mass as the universe expands—a phenomenon called 'cosmological coupling.' If further observations confirm it, cosmological coupling will redefine our understanding of what a black hole is.
Study first author Duncan Farrah, University of Hawai'i Astronomer and former Imperial Ph.D. student, said, "We're really saying two things at once: that there's evidence the typical black hole solutions don't work for you on a long, long timescale, and we have the first proposed astrophysical source for dark energy."
"What that means, though, is not that other people haven't proposed sources for dark energy, but this is the first observational paper where we're not adding anything new to the universe as a source for dark energy: black holes in Einstein's theory of gravity are the dark energy."
More information: Duncan Farrah et al, A Preferential Growth Channel for Supermassive Black Holes in Elliptical Galaxies at z ≲ 2, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/acac2e
The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/acb704. iopscience.iop.org/article/10. … 847/2041-8213/acb704
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Cosmology & The Universe
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Planning is well underway for NASA’s Habitable Worlds Observatory (HWO), which will scour the atmospheres of planets outside the solar system for telltale signs of alien life.
This week, a workshop was held at the California Institute for Technology (Caltech) at which scientists and engineers discussed the state of technology that could be employed by the HWO, one of NASA’s next big telescope projects after the James Webb Space Telescope (JWST).
The hunt for signs of life in the atmospheres of planets outside the solar system orbiting distant stars — exoplanets — is akin to hunting for a needle in a cosmic haystack. After all, NASA estimates there are several billion Earth-size planets sitting in the habitable zones of their stars, which regions with the right temperatures to allow liquid water to exist. And that's in the Milky Way alone.
Yet, scientists at least have a good idea of what they should be hunting for as well as knowledge of signs that would potentially indicate life.
"We want to probe the atmospheres of these exoplanets to look for oxygen, methane, water vapor, and other chemicals that could signal the presence of life," NASA’s Exoplanet Exploration Program chief technologist, Nick Siegler, said in a statement. "We aren't going to see little green men but rather spectral signatures of these key chemicals, or what we call biosignatures."
The HWO was first proposed as a top priority by the Decadal Survey on Astronomy and Astrophysics 2020 (Astro2020), a roadmap of goals for the astronomy community to take on over the coming decade. This is because, in addition to hunting for signs of life outside the solar system and helping astronomers understand entire planetary systems, the observatory will also play a major role in astrophysics investigations.
Though the mission is set to launch in the late 2030s or early 2040s, advancing technologies the telescope will use now could help prevent cost overruns later down the line, according to Dmitry Mawet, member of the HWO Technical Assessment Group (TAG).
Throwing shade at distant stars
To perform deep investigations of exoplanet atmospheres in order to hunt for signs of life, the HWO will tap into its ability to block out the glares of stars those exoplanets orbit.
Blocking strong light coming from these stars will allow fainter bits of starlight, reflecting off the atmospheres of orbiting planets around these stars, to be seen. Chemical elements and compounds absorb and emit light at unique wavelengths characteristic to their compositions, meaning light exposed to a planet's atmosphere carries fingerprints of elements it is made of.
Scientists take this light and, using a process called spectroscopy, search for these fingerprints. Such chemical fingerprints could include biosignatures indicating chemical compounds exhaled or inhaled by living things.
There are two main ways that the HWO could potentially block out excess starlight. On one hand, it could utilize a large external light block called a starshade, which would unfurl from the HWO after its launch into a massive sunflower-shaped umbrella.
Or alternatively, it could use an internal starshade called a coronagraph, similar to instruments scientists use to block out light from the sun’s bright photosphere to study its nebulous outer atmosphere, or corona. Siegler added that currently, NASA has decided to focus the HWO around coronagraph technology used on several other telescopes, including the JWST and forthcoming Nancy Grace Roman Telescope.
Located on the Hawaiian mountain Mauna Kea, the W. M. Keck Observatory is already using a coronagraph invented by Mawet in conjunction with the Keck Planet Imager and Characterizer (KPIC) to study exoplanets. The coronagraph lets the KPIC picture thermal emissions from young and hot gas-giant exoplanets, allowing scientists to investigate how these planets and their planetary systems evolve.
Earth-like planets that the HWO will set its sights on can emit light around 10 billion times fainter than that of their stars, meaning a coronagraph for the future space telescope would need to push starlight well past its current limits.
"As we get closer and closer to this required level of starlight suppression, the challenges become exponentially harder," Mawet added.
Suppressing starlight with a shapeshifting mirror
One of the ideas put forward at the Caltech meeting to enhance suppression of light from a distant star is to put a mirror within a coronagraph that can be deformed to control light rays.
Employing thousands of actuators to drive the shape of the mirror as well as push and pull on its reflective surfaces could stop stray light from making its way to the final image, thus preventing unwanted "blobs" of residual starlight. A deformable "active" mirror of this type is the kind set to be used by the Nancy Grace Roman Space telescope, in fact, an observatory set to launch no later than 2027. Roman should let astronomers see gas giants around a billion times fainter than their stars as well as debris around stars left over from the births of planets.
This will be a vital stepping stone towards more powerful technology that will be needed by the HWO, bridging a gap in coronagraph masks and active mirrors too great to cover in a single proverbial bound.
"We need to be able to deform the mirrors to a picometer-level of precision," Mawet explained. "We will need to suppress the starlight by another factor of roughly 100 compared to Roman’s coronagraph."
During the Caltech session, scientists also addressed the best type of mirror to use for the HWO and what it should be coated with, as well as other potential instruments for the telescope.
As planning for the HWO continues in earnest, astronomers are also at work selecting Earth-like exoplanet targets for the future telescope to train its gaze on. This hunt will include the use of the Caltech-operated Keck Planet Finder (KPF) at the Keck Observatory, which has been specially designed to look for Earth-like planets in the habitable zones of small red stars.
"The workshop helped guide us in figuring out where the gaps are in our technology and where we need to do more development in the coming decade," Mawet concluded.
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Robert Lea is a science journalist in the U.K. who specializes in science, space, physics, astronomy, astrophysics, cosmology, quantum mechanics and technology. Rob's articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University
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Cosmology & The Universe
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The greatest puzzle in cosmology just got even more puzzling.
Images from the James Webb Space Telescope have confirmed that the universe appears to be expanding significantly faster than it should be, researchers report in a study accepted in the Astrophysical Journal. The observation is in conflict with an esteemed theory, the standard model of cosmology, that describes how the universe has evolved since the first moments after the Big Bang.
The conflict comes down to calculations of the Hubble constant, a number that describes how fast everything in the universe is flying apart. One calculation, based on Planck satellite observations of the oldest light in the universe in conjunction with the standard model of cosmology, suggests the Hubble constant is 67.4 kilometers per second per megaparsec (a megaparsec is about 3 million light-years). Hubble Space Telescope images of stars at various distances from us provide a fundamentally incompatible value — 73 kilometers per second per megaparsec.
The discrepancy is known as the Hubble tension, and new JWST data hasn’t done anything to ease it (SN: 7/30/19). The telescope took images of the same stars as the Hubble telescope and calculated a very similar Hubble constant. Although the Planck number disagrees from the Hubble telescope and JWST number by less than 10 percent, the discrepancy in the measurements implies that there’s something terribly wrong with our understanding of the universe. Unless an error turns up in one of the measurements, it will take strange new physics to explain the tension.
“Papers in the literature over the last 10 years have invoked anything from weird dark matter to weird dark energy, to another [exotic] particle, to a magnetic field in the early universe to a new field, all kinds of things” to explain the Hubble tension, says cosmologist Adam Riess of Johns Hopkins University.
Some of these explanations “look semi-successful, some of them look like failures, some of them would cause other problems,” he says. Developing a theory that might resolve the tension “is still very much in the skunkworks [or extremely speculative] stage of trying to understand what [the tension] could mean.”
JWST looks to the stars to calculate the Hubble constant
With the Hubble telescope and JWST, astronomers calculate the Hubble constant by observing flashing stars known as Cepheid variables. The stars flare up periodically at rates that indicate how much light they’re putting out. Comparing a star’s brightness in telescope images with its expected brightness, based on the flare-up rates, gives a measure of the distance to the stars. Shifts in the color of the light coming from the stars reveal how fast they’re moving. Combining distance and speed observations of Cepheid stars leads to a measure of the expansion of the universe.
But Cepheid variable stars tend to sit deep inside galaxies, surrounded by crowds of other stars. That can make it difficult to get good measurements of the Cepheids’ speeds and locations. One simple resolution for the Hubble tension could have been that the Hubble telescope measurements were simply off.
Enter JWST, which can peer through the stellar crowds to clearly make out the color and brightness of Cepheid variables. The higher-resolution JWST images provide data with dramatically lower uncertainties and reduced confusion with nearby stars than the Hubble telescope could manage. The result: The Hubble telescope measurements have been right all along, Riess and colleagues report in their new paper.
This study alone isn’t enough to convince astronomer Wendy Freedman of the University of Chicago. The two galaxies studied are comparatively close to us, on cosmic scales, with the farthest one about 75 million light-years away, she notes. The relative proximity makes it easier to pick out the Cepheids from the stellar crowds. Freedman suspects it will be harder to distinguish Cepheids from the crowds of surrounding stars in more distant galaxies, even with JWST.
“The problem is only going to be worse,” Freedman says. “Because the resolution, it gets worse as you go to a higher distance.” For very distant galaxies, she suspects, stars could appear too close together to pick out the Cepheids from neighboring stars, even for JWST. As a result, Freedman says that Riess’ confirmation of the higher Hubble constant may crumble with analysis of more distant Cepheids.
JWST’s images leave the Hubble tension untouched
Hints that the measurements might hold up at larger distances arose in a Sept. 12 presentation at a conference in Baltimore dedicated to the first year of JWST science. Riess showed preliminary Cepheid data from four more galaxies. One of them is 140 million light-years away — among the most distant galaxies in the Hubble telescope Cepheid studies. JWST data from those stars also line up with the Hubble telescope measurements. Although still awaiting peer review, the images strongly suggest that the JWST has indeed overcome the uncertainties that resulted when light from Cepheids got mixed up with light from nearby stars in the lower resolution Hubble telescope images.
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University of Cambridge astrophysicist George Efstathiou, who was not involved in the study, is both convinced that Riess has gotten the measurements right and confounded by the implications. “When they showed me all of that [data],” Efstathiou says, “my reaction was, ‘Well, you know, I’m stumped.’”
Efstathiou is a member of the Planck satellite collaboration, which studied the oldest light in the universe, called the cosmic microwave background, and found the lower value for the expansion of the universe. The satellite’s calculation is based on images of the patterns in light from the early universe. Together with the standard model of cosmology, the images show that the universe is expanding with a Hubble constant that’s lower than the JWST measurement by about 5.6 kilometers per second per megaparsec.
As it stands, there doesn’t seem to be anything wrong with the Planck measurement of the Hubble constant or with the JWST observations. The tension between the measurements points a finger at the standard model of cosmology as the problem. But the standard model also appears to be unimpeachable; it’s withstood numerous other challenges without breaking down. The model came about in part due to the discovery of the accelerating expansion of the universe, which earned Riess and others a Nobel Prize in physics (SN: 10/4/11). The revelation was a key piece in shaping the model to include dark matter, dark energy and other factors, making it the simplest theory that can accurately describe the universe.
Now, though, Riess’ Cepheid-based studies of the Hubble constant show that there’s still more to learn.
“This is a crack, or a surprise that doesn’t fit,” Riess says. “It’s left us more in a kind of confused or purgatory state.” The implication, he says, is “there’s a problem with the standard model. You can revise it, but we don’t know how to revise it, which direction or in what way.”
People shouldn’t mistake the tension over the Hubble tension as despair. “It’s more of an opportunity to learn something about the universe with these telescopes,” Riess says.
One possibility is completely new physics.
“If there’s new physics, that’d be fun,” Freedman says. “We’d all like to see something new and interesting…. Either way, I think it’s going to be an exciting result — either confirming the [standard] model or showing that there’s something still in the model that’s missing.”
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Cosmology & The Universe
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Space Updated on: September 6, 2022 / 7:56 PM / CBS News NASA releases stunning Webb Telescope images NASA releases stunning Webb Telescope images, previewing discoveries to come 03:29 NASA's highly sensitive James Webb Space Telescope has captured an extremely detailed image of thousands of never-before-seen young stars in a region known as the Tarantula Nebula.Located in the Large Magellanic Cloud, which is around 160,000 light years from Earth, the nebula, also known as stellar nursery 30 Doradus, is a region of very active star formation, according to NASA's Jet Propulsion Laboratory. NASA's mosaic image of the nebula covers an area of 340 light-years. Viewed with Webb's Near-Infrared Camera (NIRCam), the region resembles a burrowing tarantula's home. But it was actually named the Tarantula Nebula for its dusty filaments captured in previous telescope images. In this mosaic image stretching 340 light-years across, Webb's Near-Infrared Camera displays the Tarantula Nebula star-forming region in a new light, including tens of thousands of never-before-seen young stars that were previously shrouded in cosmic dust. Credit: NASA, ESA, CSA, STScI, Webb ERO Production Team The nebula is home to the hottest, most massive stars known to exist. And it's of major interest to astronomers because, unlike in our Milky Way, it is producing new stars at a "furious rate." Studying the nebula also offers astronomers a unique insight into our universe's past and how stars formed in the deep cosmic past. Though close to us, the chemical make-up of the nebula is similar to the gigantic, star-forming regions from when the universe was only a few billion years old, and star formation was at its peak — a period known as "cosmic noon." The sparkling blue stars seen in the image are responsible for creating the nebula's cavity — located right at the center of the NIRCam image — with their own radiation. "Only the densest surrounding areas of the nebula resist erosion by these stars' powerful stellar winds, forming pillars that appear to point back toward the cluster," said NASA. These pillars contain young stars called "protostars," which form in cocoons of dust. Webb's NIRCam caught one very young star still gathering mass in a cloud of dust and gas."Astronomers previously thought this star might be a bit older and already in the process of clearing out a bubble around itself," NASA said. "However, NIRSpec showed that the star was only just beginning to emerge from its pillar and still maintained an insulating cloud of dust around itself. Without Webb's high-resolution spectra at infrared wavelengths, this episode of star formation in action could not have been revealed." The heart of the Tarantula Nebula as seen in mid-infrared light by the James Webb Space Telescope. NASA, ESA, CSA, STScI, Webb ERO Production Team NASA also used its Mid-Infrared Instrument (MIRI), which is capable of penetrating deeper into the cosmos than a telescope using visible light, to look at the nebula. The MIRI revealed a very different side of the celestial structure and a "previously unseen cosmic environment," NASA said. "The hot stars fade, and the cooler gas and dust glow," NASA said. "Within the stellar nursery clouds, points of light indicate embedded protostars, still gaining mass." Webb, a joint project from NASA, the European Space Agency and the Canadian Space Agency, launched on Christmas Day last year, after more than 20 years of development, and by July it has begun delivering stunning new images of the cosmos."Webb has already begun revealing a universe never seen before, and is only getting started on rewriting the stellar creation story," NASA said.Correction: This story has been updated to note that Webb launched on Christmas Day but took several more months to begin sending images. In: James Webb Space Telescope galaxy NASA Natacha Larnaud Natacha Larnaud is a social TV producer for CBS News. Thanks for reading CBS NEWS. Create your free account or log in for more features. Please enter email address to continue Please enter valid email address to continue
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Cosmology & The Universe
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An international team has spotted a remote blast of cosmic radio waves lasting less than a millisecond. This 'fast radio burst' (FRB) is the most distant ever detected. Its source was pinned down by the European Southern Observatory's (ESO) Very Large Telescope (VLT) in a galaxy so far away that its light took eight billion years to reach us. The FRB is also one of the most energetic ever observed; in a tiny fraction of a second it released the equivalent of our Sun's total emission over 30 years.
The discovery of the burst, named FRB 20220610A, was made in June last year by the ASKAP radio telescope in Australia [1] and it smashed the team's previous distance record by 50 percent.
"Using ASKAP's array of dishes, we were able to determine precisely where the burst came from," says Stuart Ryder, an astronomer from Macquarie University in Australia and the co-lead author of the study published today in Science. "Then we used [ESO's VLT] in Chile to search for the source galaxy, [2] finding it to be older and further away than any other FRB source found to date and likely within a small group of merging galaxies."
The discovery confirms that FRBs can be used to measure the 'missing' matter between galaxies, providing a new way to 'weigh' the Universe.
Current methods of estimating the mass of the Universe are giving conflicting answers and challenging the standard model of cosmology. "If we count up the amount of normal matter in the Universe -- the atoms that we are all made of -- we find that more than half of what should be there today is missing," says Ryan Shannon, a professor at the Swinburne University of Technology in Australia, who also co-led the study. "We think that the missing matter is hiding in the space between galaxies, but it may just be so hot and diffuse that it's impossible to see using normal techniques."
"Fast radio bursts sense this ionised material. Even in space that is nearly perfectly empty they can 'see' all the electrons, and that allows us to measure how much stuff is between the galaxies," Shannon says.
Finding distant FRBs is key to accurately measuring the Universe's missing matter, as shown by the late Australian astronomer Jean-Pierre ('J-P') Macquart in 2020. "J-P showed that the further away a fast radio burst is, the more diffuse gas it reveals between the galaxies. This is now known as the Macquart relation. Some recent fast radio bursts appeared to break this relationship. Our measurements confirm the Macquart relation holds out to beyond half the known Universe," says Ryder.
"While we still don't know what causes these massive bursts of energy, the paper confirms that fast radio bursts are common events in the cosmos and that we will be able to use them to detect matter between galaxies, and better understand the structure of the Universe," says Shannon.
The result represents the limit of what is achievable with telescopes today, although astronomers will soon have the tools to detect even older and more distant bursts, pin down their source galaxies and measure the Universe's missing matter. The international Square Kilometre Array Observatory is currently building two radio telescopes in South Africa and Australia that will be capable of finding thousands of FRBs, including very distant ones that cannot be detected with current facilities. ESO's Extremely Large Telescope, a 39-metre telescope under construction in the Chilean Atacama Desert, will be one of the few telescopes able to study the source galaxies of bursts even further away than FRB 20220610A.
Notes
[1] The ASKAP telescope is owned and operated by CSIRO, Australia's national science agency, on Wajarri Yamaji Country in Western Australia.
[2] The team used data obtained with the FOcal Reducer and low dispersion Spectrograph 2 (FORS2), the X-shooter and the High Acuity Wide-field K-band Imager (HAWK-I) instruments on ESO's VLT. Data from the Keck Observatory in Hawai'i, US, was also used in the study.
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Cosmology & The Universe
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New research puts age of universe at 26.7 billion years, nearly twice as old as previously believed
Our universe could be twice as old as current estimates, according to a new study that challenges the dominant cosmological model and sheds new light on the so-called "impossible early galaxy problem."
The work is published in the journal Monthly Notices of the Royal Astronomical Society.
"Our newly-devised model stretches the galaxy formation time by a several billion years, making the universe 26.7 billion years old, and not 13.7 as previously estimated," says author Rajendra Gupta, adjunct professor of physics in the Faculty of Science at the University of Ottawa.
For years, astronomers and physicists have calculated the age of our universe by measuring the time elapsed since the Big Bang and by studying the oldest stars based on the redshift of light coming from distant galaxies. In 2021, thanks to new techniques and advances in technology, the age of our universe was thus estimated at 13.797 billion years using the Lambda-CDM concordance model.
However, many scientists have been puzzled by the existence of stars like the Methuselah that appear to be older than the estimated age of our universe and by the discovery of early galaxies in an advanced state of evolution made possible by the James Webb Space Telescope. These galaxies, existing a mere 300 million years or so after the Big Bang, appear to have a level of maturity and mass typically associated with billions of years of cosmic evolution. Furthermore, they're surprisingly small in size, adding another layer of mystery to the equation.
Zwicky's tired light theory proposes that the redshift of light from distant galaxies is due to the gradual loss of energy by photons over vast cosmic distances. However, it was seen to conflict with observations. Yet Gupta found that "by allowing this theory to coexist with the expanding universe, it becomes possible to reinterpret the redshift as a hybrid phenomenon, rather than purely due to expansion."
In addition to Zwicky's tired light theory, Gupta introduces the idea of evolving "coupling constants," as hypothesized by Paul Dirac. Coupling constants are fundamental physical constants that govern the interactions between particles. According to Dirac, these constants might have varied over time. By allowing them to evolve, the timeframe for the formation of early galaxies observed by the Webb telescope at high redshifts can be extended from a few hundred million years to several billion years. This provides a more feasible explanation for the advanced level of development and mass observed in these ancient galaxies.
Moreover, Gupta suggests that the traditional interpretation of the "cosmological constant," which represents dark energy responsible for the accelerating expansion of the universe, needs revision. Instead, he proposes a constant that accounts for the evolution of the coupling constants. This modification in the cosmological model helps address the puzzle of small galaxy sizes observed in the early universe, allowing for more accurate observations.
More information: R Gupta, JWST early Universe observations and ΛCDM cosmology, Monthly Notices of the Royal Astronomical Society (2023). DOI: 10.1093/mnras/stad2032
Journal information: Monthly Notices of the Royal Astronomical Society
Provided by University of Ottawa
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Cosmology & The Universe
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HomeSpaceScientists May Find ‘Evidence’ of Another Universe Before Our Own Scientists find proof of previous universes in the night
sky, namely the leftovers of black holes from a previous universe.The detailed, all-sky picture of the infant universe created
from nine years of WMAP data. The image reveals 13.77 billion year old
temperature fluctuations (shown as color differences) that correspond to the
seeds that grew to become the galaxies. The signal from our galaxy was
subtracted using the multi-frequency data. This image shows a temperature range
of ± 200 microKelvin.CREDIT:
NASA/WMAP SCIENCE TEAM CREDIT: NASA/WMAP SCIENCE TEAM According to New Scientist, the concept is based on
something known as conformal cyclic cosmology (CCC). What it means is that our
universe, rather than beginning with a single Big Bang, goes through continual
cycles of Big Bangs and compressions. While the vast majority of the cosmos would be annihilated
from one cycle to the next, these scientists claim that some electromagnetic
radiation may survive the recycling process. Their findings have been published
on arXiv. “What we claim we’re seeing is the final remnant after a
black hole has evaporated away in the previous aeon,” University of Oxford
mathematical physicist Roger Penrose, a co-author on the study and co-creator
of CCC theory, told New Scientist. The evidence is presented in the form of "Hawking
points," which are named after the late Stephen Hawking. He hypothesised
that black holes would release Hawking radiation, which Penrose and his
colleagues claim may travel from one universe to the next. They believe Hawking points might arise in the cosmic
microwave background, which is the leftover radiation from the Big Bang (CMB).
On the CMB map, hawking spots would appear as rings of light known as B-modes. Previously, it was considered that these aberrant locations
in the CMB were created by gravitational waves or interstellar dust. However,
Penrose and his colleagues believe their theory may give an exciting response,
and one such Hawking point may have already been discovered by the BICEP2
project, which aims to map the CMB. “Though seemingly problematic for cosmic inflation, the
existence of such anomalous points is an implication of conformal cyclic
cosmology (CCC),” the team wrote in their paper. “Although of extremely low temperature at emission, in CCC
this radiation is enormously concentrated by the conformal compression of the
entire future of the black hole, resulting in a single point at the crossover
into our current aeon.” The recycling universe idea is not without debate. The
majority of our data imply that the universe's expansion is accelerating, with
the cosmos not being dense enough to condense back into a single point and
expand again - a notion known as the Big Bounce.
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Cosmology & The Universe
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Does anybody remember GLASS-z13? No?It was spotted by the James Webb Space Telescope and championed as the "oldest galaxy ever seen" and it was announced... six days ago.Yes, that's right. Not even a week ago, two pre-print papers posted to scientific article repository arXiv (pronounced "archive") detailed some of the earliest analysis of images snapped by the JWST, humanity's next-generation infrared eye on the cosmos. Lurking within the data were two galaxies -- potentially the most distant galaxies humans had ever laid eyes on. One of them was dubbed GLASSz-13 or GL-z13 for short (The Atlantic gave it the cutesy name of "Glassy")."JWST has found the oldest galaxy we have ever seen in the universe" one headline read. The story exploded across the web, with Twitter buzzing about it and mainstream outlets picking up on the record-breaking find. It even got its own Wikipedia page!In the rush of reporting, a few key points were missed. It's not the "oldest galaxy" we've ever seen. It's maybe the oldest light we've ever detected but it's probably a very young galaxy, no more than a 100 billion years into its life (an important distinction). It's also important to note GL-z13 is currently just a "candidate" that requires further investigation -- the data is pretty good, according to astronomers I've spoken with -- but further observations would help tick it off as the record holder. But all that might not even matter. Hubble and James Webb Space Telescope Images Compared: See the Difference See all photos In a slew of new papers dropped on arXiv Monday, astronomers have picked out galaxies that may lie even further away than GL-z13. It's a showcase of the power of the revolutionary James Webb Space Telescope.As soon as researchers were given access to Webb's first batch of data, they began scouring it for distant galaxies. Webb is the best at finding these galaxies because it sees the cosmos in infrared light, rather than visible light, like the Hubble Space Telescope does.Visible light from the very earliest galaxies in the universe has been "redshifted." Because the universe has been expanding since the Big Bang, wavelengths of light get stretched out. When you stretch the light we can see with our eyes, that stretching shifts it toward a redder wavelength. In this case, infrared. Webb is designed specifically to capture this light.Astronomers denote redshift with z. Higher z values essentially represent a further look back in time. For instance, z = 1 corresponds to around 7.7 billion years ago, whereas z = 10 corresponds to around 13.2 billion years ago.In the papers uploaded to arXiv, at least three have presented candidate galaxies with a z value greater than 16. This would correspond to around 13.6 billion years ago. One presents a case for a galaxy at z = 16.7, which would correspond to about 250 million years after the Big Bang.This pixelated red dot could be a galaxy that existed just a few 100 million years after the Big Bang. The scale bar is 1 kiloparsec (about 3,260 light-years). Finkelstein et al. (2022)/NASA/ESA/CSA/STScI Another, summarized by astrophysicist Steve Finklestein in this Twitter thread, presents a galaxy at z > 14. Finkelstein named it Maisie's Galaxy, after his daughter.The discoveries have astronomers on Twitter buzzing yet again, but where does this leave GL-z13? Well its z value is about 13 (as the name might suggest), so perhaps it's Game Over for Glassy.However, it's still got a shot at becoming the most distant galaxy ever observed because astrophysicists need to validate what they're seeing in the JWST data."Many of the candidates in these papers aren't as convincing [as GL-z13]," said Michael Brown, an astrophysicist at Monash University in Melbourne.There's even more uncertainty about distances when you bring in the gentle disagreement between astrophysicists about how fast the universe is expanding. We won't get into that here. In short, confirmation of these galaxies as bonafide galaxies will require further observations which are very likely to come during the first years of Webb's operation.And yes, the Webb Space Telescope is poised to deliver even more candidates for the most distant galaxy ever observed beyond today. They might even drop on arXiv tomorrow! While many of these candidates will soon fade from the public consciousness, each will provide a stepping stone for astrophysicists to piece together the earliest moments of our universe. Some of the questions these galaxies will answer haven't even been asked yet.In fact, astrophysicists are already finding the early universe might be a lot more busy than they expected. Stars may have started forming at a much faster rate than some models have predicted. How did matter coalesce and start to form these galaxies early on? We don't know yet. But Webb is, seemingly, already rewriting what we thought we knew about the beginning of, well, everything.It's an astronomical revolution. So strap in. It's going to be one hell of a ride.
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Cosmology & The Universe
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Could dark photon dark matter be directly detected using radio telescopes?
Dark matter, matter in the universe that does not emit, absorb or reflect light, cannot be directly detected using conventional telescopes or other imaging technologies. Astrophysicists have thus been trying to identify alternative methods to detect dark matter for decades.
Researchers at Tsinghua University, the Purple Mountain Observatory and Peking University recently carried out a study exploring the possibility of directly detecting dark photons, prominent dark matter candidates, using radio telescopes. Their paper, published in Physical Review Letters, could inform future searches for dark photons, which are hypothetical particles that would carry a force in dark matter, similarly to how photons carry electromagnetism in normal matter.
"This process involves the excitation of free electrons by dark photon fields, leading to the emission of normal photons. Building on this work, Jia and I considered using the free electrons in a dished telescope to induce electromagnetic signals and then using the FAST telescope to search for search such a signal."
Soon after, they started exploring the use of dished telescopes to search for dark photon-related electromagnetic signals, An and his colleagues realized that due to the non-relativistic nature of dark matter, the reflector in such telescopes would need to be spherical and the receiver of the signal should be placed at the center of this sphere.
Existing dished radio telescopes, however, such as the five-hundred-meter aperture spherical radio telescope (FAST) in China, are designed to observed remote radio signals, thus the shape of their dish is parabolic, with the receiver placed at the point of focus.
This meant that electromagnetic signals induced by dark photons would not concentrate at their receiver.
"After this realization, we temporarily gave up on this idea," An explained. "In the summer of 2021, I was invited to give lectures about dark matter at the UFITS summer school for cosmology held at the FAST site, where I studied the details of how the FAST telescope works. I learned that the receiver suspended above the dish could move around such that the telescope could observe radio waves from different directions. I then came up with the idea that although the dark photon dark matter-induced EM waves are not focused on the receiver, the EM field can form a distribution on top of the dish, and this distribution can be accurately calculated theoretically."
According to An's subsequent theoretical predictions, the movable receiver in radio telescopes should be able to collect electromagnetic signals in different locations. The signals collected by the receiver could then be compared to distributions predicted by theory, which would help to improve the sensitivity of the telescopes to dark photon-induced signals.
"With our colleagues, we then started to calculate this signal," An said. "To our surprise, we found that even without considering the distribution, with the extraordinary sensitivity, even with the fact that the dark photon dark matter induced signal is not focused at the receiver, the sensitivity of the FAST telescope has already surpassed the CMB constraint, which means that the FAST telescope can discover the dark matter if the dark matter is composed by dark photon and is in the right mass region."
To further assess the viability of their proposed method to search for dark photons, An and his colleagues also analyzed observation data collected by the FAST radio telescope, which is located in a village in the mountains in the Guizhou region in China. This data was provided by Prof. Xiaoyuan Huang, who is also a co-author of the recent paper.
"We analyzed the data and placed the most stringent bound on the model in the 1–1.5 GHz frequency range," An said. "We realized that dark photon dark matter could induce electric signals on dipole antennas and that due to the non-relativistic nature, we could use interferometry technology to improve the sensitivity, Therefore, we calculate the potential sensitivity of the LOFAR telescope and the future SKA telescope and find they both have the potential to discover dark photon dark matter. "
Overall, the analyses conducted by this team of researchers suggest that radio telescopes could potentially enable the direct detection of dark photons. Their work could thus broaden horizons in the ongoing search for dark photons, particularly ultra-light dark photons.
"In the early 1960s, while conducting research in radio astronomy, Penzias and Wilson stumbled upon an unexpected low-level background noise," An said. "This noise was later confirmed to be the cosmic microwave background radiation, providing important evidence for the hot early expansion of the universe. Ultra-light dark photons exhibit photon-like electromagnetic interactions through kinetic mixing with photons. As a candidate for diffuse dark matter in the universe, ultra-light dark photons can display behavior similar to that of cosmic microwave background radiation. By carefully listening with modern radio telescopes, elusive whispers from the dark world may be heard."
Ultralight dark photons can behave similarly to dark electromagnetic fields with specific frequencies, and this research team showed that it could potentially be detected using radio telescopes, instruments that are commonly used to observe cosmic microwave background. In the future, their theoretical considerations could inform searches for dark photon dark matter that rely on large-scale radio telescope observations.
"Our work may open a new sub-area in radio astronomy," An added. "We now plan to search for dark photon dark matter signals in the data from LOFAR and MeerKAT telescopes. We also plan to apply this idea to search for axion dark matter, another competitive ultralight dark matter candidate."
More information: Haipeng An et al, Direct Detection of Dark Photon Dark Matter Using Radio Telescopes, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.181001
Journal information: Physical Review Letters
© 2023 Science X Network
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Cosmology & The Universe
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Space September 21, 2022 / 1:51 PM / CBS/AFP The James Webb Space Telescope has turned its gaze away from the deep universe toward our home Solar System, capturing an image of a luminous Neptune and its delicate, dusty rings in detail not seen in decades, NASA said Wednesday. Hey Neptune. Did you ring? 👋Webb’s latest image is the clearest look at Neptune's rings in 30+ years, and our first time seeing them in infrared light. Take in Webb's ghostly, ethereal views of the planet and its dust bands, rings and moons: https://t.co/Jd09henF1F #IAC2022 pic.twitter.com/17QNXj23ow— NASA Webb Telescope (@NASAWebb) September 21, 2022 The last time astronomers had such a clear view of the farthest planet from the sun was when NASA's Voyager 2 became the first and only space probe to fly past the ice giant for just a few hours in 1989.Now Webb's unprecedented infrared imaging capabilities has provided a new glimpse into Neptune's atmosphere, said Mark McCaughrean, a senior advisor for science and exploration at the European Space Agency. The telescope "takes all that glare and background away" so that "we can start to tease out the atmospheric composition" of the planet, McCaughrean, who has worked on the Webb project for more than 20 years, told AFP.Neptune appears as deep blue in previous images taken by the Hubble Space Telescope due to methane in its atmosphere. However the near-infrared wavelengths captured by Webb's primary imager NIRCam shows the planet as a greyish white, with icy clouds streaking the surface. "The rings are more reflective in the infrared," McCaughrean said, "so they're much easier to see."The image also shows an "intriguing brightness" near the top of Neptune, NASA said in a statement. Because the planet is tilted away from Earth and takes 164 years to orbit the Sun, astronomers have not yet had a good look at its north pole.Webb also spotted seven of Neptune's 14 known moons. This composite image provided by NASA on Sept. 21, 2022, shows three side-by-side images of Neptune. From left, a photo of Neptune taken by Voyager 2 in 1989, Hubble in 2021, and Webb in 2022. AP Looming over Neptune in a zoomed-out image is what appears to be a very bright spiky star, but is in fact Triton, Neptune's strange, huge moon haloed with Webb's famed diffraction spikes. Triton, which is larger than dwarf planet Pluto, appears brighter than Neptune because it is covered in ice, which reflects light. Neptune meanwhile "absorbs most of the light falling on it," McCaughrean said.Because Triton orbits the wrong way around Neptune, it is believed to have once been an object from the nearby Kuiper belt which was captured in the planet's orbit."So it's a pretty cool to go and have a look at," said McCaughrean.As astronomers sweep the universe searching for other planets like our own, they have found that ice giants such as Neptune and Uranus are the most common in the Milky Way."By being able to look at these ones in great detail, we can key into our observations of other ice giants," McCaughrean said.Operational since July, Webb is the most powerful space telescope ever built, and has already unleashed a raft of unprecedented data. Scientists are hopeful it will herald a new era of discovery.Research based on Webb's observations of both Neptune and Triton is expected in the next year. "The kind of astronomy we're seeing now was unimaginable five years ago," McCaughrean said."Of course, we knew that it would do this, we built it to do this, it is exactly the machine we designed," he said. "But to suddenly start seeing things in these longer wavelengths, which were impossible before... it's just absolutely remarkable." This image provided by NASA on Wednesday, Sept. 21, 2022, shows the Neptune system captured by Webb's Near-Infrared Camera. / AP Earlier this month, the world's newest and biggest space telescope captured an extremely detailed image of thousands of never-before-seen young stars in a region known as the Tarantula Nebula.This summer, the telescope captured a stunning images of Jupiter and also provided the clearest look of the Cartwheel Galaxy so far. Unlike the Hubble Space Telescope, which mostly observes light in the visible part of the spectrum, Webb is optimized to study longer-wavelength infrared radiation, allowing it to capture light from the dawn of the universe that's been stretched out by the expansion of space itself over the past 13.8 billion years.Last month, the European Space Agency released a new photo capturing the heart of Messier 74, located 32 million light years away in the Pisces constellation, in a view that combines the Hubble telescope with the Webb telescope. In: James Webb Space Telescope NASA Thanks for reading CBS NEWS. Create your free account or log in for more features. Please enter email address to continue Please enter valid email address to continue
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Cosmology & The Universe
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How fast is the universe really expanding? Multiple views of an exploding star raise new questions
How did we get here? Where are we going? And how long will it take? These questions are as old as humanity itself, and, if they've already been asked by other species elsewhere in the universe, potentially very much older than that.
They are also some of the fundamental questions we are trying to answer in the study of the universe, called cosmology. One cosmological conundrum is how fast the universe is expanding, which is measured by a number called the Hubble constant. And there is quite a bit of tension around it.
In two new papers led by my colleague Patrick Kelly at the University of Minnesota, we have successfully used a new technique—involving light from an exploding star that arrived at Earth via multiple winding routes through the expanding universe—to measure the Hubble constant. The papers are published in Science and The Astrophysical Journal.
And if our results don't quite resolve the tension, they do give us another clue—and more questions to ask.
Standard candles and the expanding universe
We have known since the 1920s that the universe is expanding.
Around 1908, US astronomer Henrietta Leavitt found a way to measure the intrinsic brightness of a kind of star called a Cepheid variable—not how bright they appear from Earth, which depends on distance and other factors, but how bright they really are. Cepheids grow brighter and dimmer in a regular cycle, and Leavitt showed the intrinsic brightness was related to the length of this cycle.
Leavitt's Law, as it is now called, lets scientists use Cepheids as "standard candles": objects whose intrinsic brightness is known, and therefore, whose distance can be calculated.
How does this work? Imagine it is night, and you are standing on a long, dark street with only a few light poles going down the road. Now imagine every light pole has the same type of light bulb, with the same power. You'll notice the distant ones appear fainter than the nearby ones.
We know that light fades proportionately to its distance, in something called the inverse-square law for light. Now, if you can measure how bright each light appears to you, and if you already know how bright it should be, you can then figure out how far away each light pole is.
In 1929, another US astronomer, Edwin Hubble, was able to find a number of these Cepheid stars in other galaxies and measure their distance—and from those distances and other measurements, he could determine that the universe was expanding.
Different methods give different results
This standard candle method is a powerful one, allowing us to measure the vast universe. We are always looking for different candles that can be better measured, and seen at much greater distances.
Some recent efforts to measure the universe further from Earth, like the SH0ES project I was a part of, led by Nobel laureate Adam Riess, have used Cepheids alongside a type of exploding star called a Type Ia supernova, which can also be used as a standard candle.
There are also other methods to measure Hubble's constant, such as one that uses the cosmic microwave background—relic light or radiation that began to travel through the universe shortly after the Big Bang.
The problem is that these two measurements, one nearby using supernovae and Cepheids, and one much farther away using the microwave background, differ by nearly 10%. Astronomers call this difference the Hubble tension, and have been looking for new measurement techniques to resolve it.
A new method: gravitational lensing
In our new work, we have successfully used a new technique to measure this expansion rate of the universe. The work is based on a supernova called Supernova Refsdal.
In 2014, our team spotted multiple images of the same supernova—the first time such a "lensed" supernova had been observed. Instead of the Hubble Space Telescope seeing one supernova, we saw five!
How does this happen? The light from the supernova went out in all directions, but it traveled through space warped by the enormous gravitational fields of a huge cluster of galaxies, which bent some of the light's path in such a way that it ended up coming to Earth via multiple routes. Each appearance of the supernova had reached us along a different path through the universe.
Imagine three trains leaving the same station at the same time. However, one goes directly to the next station, the other makes a wide trip through the mountains, and another via the coast. They all leave and arrive at the same stations, but take different trips and so while they leave at the same time, they will arrive at different times.
So our lensed images show the same supernova, that exploded at one certain point in time, but each image has traveled a different path. By looking at the arrival at Earth of each appearance of the supernova—one of which happened in 2015, after the exploding star had been spotted already—we were able to measure their travel time, and therefore how much the universe had grown while the image was in transit.
Are we there yet?
This gave us a different, but unique measurement of the growth of the universe. In the papers, we find this measurement is closer to the cosmic microwave background measurement, rather than the nearby Cepheid and supernova measurement. However, based on its location, it should be closer to the Cepheid and supernova measurement.
While this does not settle the debate at all, it gives us another clue to look at. There could be a problem with the supernova value, or our understanding of galaxy clusters and the models to apply to lensing, or something else entirely.
Like the kids in the back of the car on a road trip asking "are we there yet", we still don't know.
Provided by The Conversation
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Cosmology & The Universe
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How did the universe come to be? The prevailing theory is everything that is began with the Big Bang. In a nutshell, the theory suggests everything, everywhere, all at once suddenly burst to life. The caveat being everything and everywhere prior to the Big Bang is fairly hard to conceptualize. The Big Bang theory is currently the best model we have for the birth of our universe. Astrophysicists have shown the theory explains, fairly comprehensively, phenomena we've observed in space over decades, like lingering background radiation and elemental abundances. It's a robust framework that gives us a pretty good idea of how the cosmos came into being some 13.8 billion years ago. But with the flurry of preprint papers and popular science articles about the James Webb Space Telescope's first images, old, erroneous claims that the Big Bang never happened at all have been circulating on social media and in the press in recent weeks. One scientist has claimed that the JWST images are inspiring "panic among cosmologists" -- that is, the scientists who study the origins of the universe.This is simply not true. The JWST has not provided evidence disproving the Big Bang theory, and cosmologists aren't panicking. Why, then, are we seeing viral social media posts and funky headlines that suggest the Big Bang didn't happen at all?To answer that question, and show why we should be skeptical of claims like this, we need to understand where the idea came from. Where did "the Big Bang didn't happen" come from?It all started with an article at The Institute of Art and Ideas, a British philosophical organization, on Aug. 11. The piece was written by Eric Lerner, who has long argued against the Big Big theory. He even wrote a book titled The Big Bang Never Happened in 1991. This provocatively headlined article at IAI is also related to an upcoming debate Lerner is participating in, run by the IAI, dubbed "Cosmology and the Big Bust." Lerner's article gathered steam across social media, being shared widely on Twitter and across Facebook, over the last week. It makes sense why it's caught fire: It's a controversial idea that upends what we think we know about the cosmos. In addition, it's tied to a new piece of technology in the James Webb telescope, which is seeing parts of the universe we've never been able to see before. Including Webb as the news hook here suggests there's new data which overturns a long-standing theory.Don't get me wrong -- there is new and intriguing data emerging from the JWST. Just not the kind that would undo the Big Bang theory. Most of this new data trickles down to the public in the form of scientific preprints, articles that are yet to undergo peer review and land on repositories like arXiv, or popular press articles.Lerner's piece uses some of the early JWST studies to attempt to dismiss the Big Bang theory. What's concerning is how it misconstrues early JWST data to suggest that astronomers and cosmologists are worried the well-established theory is incorrect. There are two points early in Lerner's article which show this:He points to a preprint with the word "Panic!" in its title, calling it a "candid exclamation."He misuses a quote from Allison Kirkpatrick, an astronomer at the University of Kansas. The first point is just a case of Lerner missing the pun. The full title of the paper is "Panic! At the Disks: First Rest-frame Optical Observations of Galaxy Structure at z>3 with JWST in the SMACS 0723 Field." The first author of that preprint, astronomer Leonardo Ferreira, is clearly riffing on popular 2000s emo band Panic! at the Disco with his title. It's a tongue-in-cheek reference, not a cosmological crisis. As for the second point, Lerner takes this quote from Allison Kirkpatrick, which comes from a Nature news article published on July 27:"Right now I find myself lying awake at three in the morning and wondering if everything I've done is wrong."This cherrypicked quote isn't in direct reference to the Big Bang theory. Rather, Kirkpatrick is reckoning with the first data coming back from the JWST about the early evolution of the universe. It's true there are some puzzles for astronomers to solve here, but, so far, they aren't rewriting the beginning of the universe to do so. Kirkpatrick has stated her quotes were misused and even changed her Twitter name to "Allison the Big Bang happened Kirkpatrick." "We as scientists have a responsibility to educate the public, and I take that responsibility very seriously," Kirkpatrick told CNET. "Deliberately misleading the public makes it difficult for them to trust real scientists and to know fact from fiction."In addition, Lerner's article claims that his ideas are being censored by the scientific establishment, and later he also points to his theory being important to develop fusion energy on Earth. It's no coincidence the same paragraph links to LPPFusion, a company run by Lerner aimed at developing clean energy technologies.Why does this matter?One of the chief reasons the Big Bang theory stands up is because of the cosmic microwave background. This was discovered in 1964. In short, the CMB is the radiation leftover from the Big Bang, right when the universe began and scientists have been able to "see" it with satellites that can detect that lingering radiation. So to bolster evidence the Big Bang theory is incorrect, you'd need to explain the CMB another way. Lerner's dismissive of the CMB, and his proposal for the observation has been disproven in the past. If you're interested in further arguments against Lerner's hypotheses and why the claims don't add up, I recommend checking out Brian Keating's recent YouTube video. Keating is a cosmologist at the University of California, San Diego, and dives into a bit more detail about the limits of Lerner's arguments.It's also important to note Webb is not built to see and undertake new analyses of the CMB itself. The telescope can't "see" that far back in time. However, it will look at an epoch a few hundred million years after the Big Bang. What it finds there will almost certainly reshape our views on the early universe, galaxies and the evolution of the cosmos. But it's disingenuous to claim the early images and study results have contradicted the Big Bang theory.Kirkpatrick notes JWST's images actually do the opposite. She said they "support the Big Bang model because they show us that early galaxies were different than the galaxies we see today -- they were much smaller!"Science is about making incremental progress in our understanding, coming to increasingly stronger conclusions based on observations. The observations astrophysicists and cosmologists have made over decades line up with the Big Bang theory. They don't line up anywhere near as neatly if we use Lerner's alternative theory. That's doesn't mean scientists won't find evidence overturning the Big Bang theory. They just might! But, for now, it remains our best theory for explaining what we see. Scientific theories can -- and should -- be challenged by well-reasoned scientists presenting highly detailed and thoughtful arguments. This is not one of those times. And that means, despite the headlines, the Big Bang did happen. Updated Aug 22: Added Kirkpatrick's quotes.
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Cosmology & The Universe
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Space August 30, 2022 / 8:44 AM / CBS News New James Webb Space Telescope images released Images from James Webb Space Telescope reveal more of the universe 05:27 The veteran and the new kid on the block have teamed up to produce a spectacular image of the Phantom Galaxy. The European Space Agency released a new photo Monday capturing the heart of Messier 74, located 32 million light years away in the Pisces constellation. It's a view that combines the Hubble Space Telescope's strong vision at ultraviolet and visible wavelengths with the James Webb Space Telescope's unprecedented sensitivity at infrared wavelengths. "By combining data from telescopes operating across the electromagnetic spectrum, scientists can gain greater insight into astronomical objects than by using a single observatory – even one as powerful as Webb," the space agency said. M74 shines at its brightest in this combined optical/mid-infrared image, featuring data from both the NASA/ESA Hubble Space Telescope and the NASA/ESA/CSA James Webb Space Telescope. European Space Agency M74 is made up of about 100 billion stars and two symmetrical "arms." It is in a subclass of spiral galaxies known as a "grand design spiral," meaning it has prominent and well-defined arms, whereas some other galaxies are not as clear. Its characteristics make it a "favorite target" for astronomers, the space agency says. Launched in 1990, Hubble has spent decades beaming jaw-dropping images back to Earth, exponentially expanding our understanding of the cosmos. The Webb Telescope, the most expensive science probe ever built, launched just this year, with the goal of studying the origins of the universe. Webb has already beamed back the most detailed images of space seen to date, and scientists are eager to combine its findings with past revelations to continue piecing together our universe's history. Webb's superior technology beautifully reveals the gas and dust spiraling outward from the heart of M74. The agency said that the image also shows off a clear view of the nuclear star cluster at the center, thanks to a lack of gas in the area. ESA highlighted the images each telescope captured on its own — as well as the power of combining them. The dust in the image is colored red, young stars can be seen in blue and older stars are yellow, marked by a "spooky green glow" when the colors combine. On the left, the Hubble Space Telescope's view of the galaxy. On the right, the James Webb Space Telescope's image is strikingly different. The combined image in the center merges these two for a truly unique look at this "grand design" spiral galaxy. European Space Agency Webb captured the galaxy using its Mid-InfraRed Instrument in its quest to study the earliest phases of star formation. It's part of a larger collaborative effort to document 19 nearby star-forming galaxies that have already been studied using both Hubble and observatories on Earth. "The addition of crystal-clear Webb observations at longer wavelengths will allow astronomers to pinpoint star-forming regions in the galaxies, accurately measure the masses and ages of star clusters, and gain insights into the nature of the small grains of dust drifting in interstellar space," the agency said. In: James Webb Space Telescope galaxy NASA Sophie Lewis Sophie Lewis is a social media producer and trending writer for CBS News, focusing on space and climate change. Thanks for reading CBS NEWS. Create your free account or log in for more features. Please enter email address to continue Please enter valid email address to continue
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Cosmology & The Universe
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Largest catalog of exploding stars now available
Celestial phenomena that change with time such as exploding stars, mysterious objects that suddenly brighten and variable stars are a new frontier in astronomical research, with telescopes that can rapidly survey the sky revealing thousands of these objects.
The largest data release of relatively nearby supernovae (colossal explosions of stars), containing three years of data from the University of Hawaiʻi Institute for Astronomy's (IfA) Pan-STARRS telescope atop Haleakalā on Maui, is publicly available via the Young Supernova Experiment (YSE). The project, which began in 2019, surveyed more than 1,500 square degrees of sky every three days, and discovered thousands of new cosmic explosions and other astrophysical transients, dozens of them just days or hours after exploding.
The newly-released data contains information on nearly 2,000 supernovae and other luminous variable objects with observations in multiple colors. It is also the first to extensively use the multi-color imaging to classify the supernovae and estimate their distances.
Astrophysicists use large imaging surveys—systematic studies of large areas of the sky over time—and different parts of the electromagnetic spectrum for many scientific goals. Some are used to study distant galaxies and how they evolve over cosmic time, or look at specific regions of the sky that are especially important, such as the Andromeda Galaxy.
"Pan-STARRS produces a steady stream of transient discoveries, observing large areas of the sky every clear night with two telescopes," said Mark Huber, a senior researcher at IfA.
"With over a decade of observations, Pan-STARRS operates one of the best calibrated systems in astronomy, with a detailed reference image of the static sky visible from Haleakalā. This enables rapid discovery and follow-up of supernovae and other transient events, well suited for programs like YSE to build up the sample required for analysis and this significant data release."
YSE is designed to find energetic astrophysical "transient" sources such as supernovae, tidal disruption events and kilonovae (extremely energetic explosions). These transients evolve quickly, rising to their maximum brightness and then fading away after a few days or months.
Multi-institution collaboration
The images from Pan-STARRS are transferred to UH's Information Technology Center for initial processing and scientific calibration by the Pan-STARRS Image Processing Pipeline. Higher-level processing, detailed analysis and storage was then performed using computing systems at the National Center for Supercomputing Applications' (NCSA) Center for Astrophysical Surveys (CAPS), the University of California, Santa Cruz (UCSC), and the Dark Cosmology Centre (DARK) at the Niels Bohr Institute at the University of Copenhagen.
The survey and the tools used to analyze the data are critical precursors to the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time, a new 8.4-meter telescope being built in Chile. Rubin Observatory will survey the entire sky every three nights, discovering so many variable and exploding objects that it will be impossible to obtain detailed follow-up observations. The ability to classify these objects from the survey data alone will be vital to choosing the most interesting ones for astronomers to target with other telescopes.
Gautham Narayan, deputy director of CAPS, is leading the cosmological analysis for the data sample and former CAPS graduate fellow Patrick Aleo is lead author of the paper, "The Young Supernova Experiment Data Release 1 (YSE DR1): Light Curves and Photometric Classification of 1975 Supernovae."
"Much of the time-domain universe is uncharted. We still do not know the progenitor systems of many of the most common classes of transients, such as type Ia supernovae, while still using these sources to try and understand the expansion history of our universe," Narayan said. "We've also seen one electromagnetic counterpart to a binary neutron star merger. There are many kinds of transients that are theoretically predicted, but have never been seen at all."
Ken Chambers, Pan-STARRS director, added that "this collaboration with the Young Supernova Experiment makes exceptional use of Pan-STARRS' ability to routinely survey the sky for transient phenomena and moving objects. We have provided an unprecedented sample of young supernovae discovered before their peak luminosity that will be an important resource for supernova researchers and cosmologists for many years. Looking ahead, Pan-STARRS will remain a crucial resource in the Northern Hemisphere to complement the Rubin Observatory in the Southern Hemisphere."
This groundbreaking effort is a collaboration between UH, UCSC, DARK, NCSA and University of Illinois—Urbana-Champaign (UIUC) and the University of Hawaiʻi. The collaboration used Hawaiʻi's Pan-STARRS1 telescope and data pipeline to collect and process the images, DARK's analysis of the data on its computing cluster, UCSC's organization of the survey and data hosting, and NCSA and UIUC's analysis.
The study is published on the arXiv preprint server.
More information: . D. Aleo et al, The Young Supernova Experiment Data Release 1 (YSE DR1): Light Curves and Photometric Classification of 1975 Supernovae, arXiv (2022). DOI: 10.48550/arxiv.2211.07128
Journal information: arXiv
Provided by University of Hawaii at Manoa
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Cosmology & The Universe
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silly string — Cosmic strings' greatest power? Their ability to confound physicists. Enlarge / A computer-generated simulation of cosmic strings.Chris Ringeval Remember that time in the Lord of the Rings lore when the dwarves of Moria dug too greedily and too deep, unearthing the Balrog, an ancient horror not meant to roam free in the modern age?
Cosmic strings are kind of like that but for physics. They are hypothetical leftovers from the momentous transformations experienced by our Universe when it was less than a second old. They are defects, flaws in space itself. They’re no wider than a proton, but they may potentially stretch across the observable volume of the Universe. They have unspeakable powers—the ability to warp space so much that circles around them never complete, and they carry enough energy to unleash planet-destroying levels of gravitational waves. They’re also the path into some of the most exotic physics known (and unknown) to science.
But perhaps the greatest power cosmic strings possess is their capacity to confound physicists. According to our best understanding of the early Universe, our cosmos should be riddled with cosmic strings. And yet not a single search has found any evidence for them. Figuring out where the cosmic strings are hiding, or why they shouldn’t exist after all, will help push our understanding of cosmology and fundamental physics to new heights.
And no, we won’t need a wizard.
A broken universe
Let’s turn the clock back to some of the earliest moments in the history of the Universe. At that time, the cosmos was less than a fraction of a second old, and its entire observable volume, currently around 90 billion light-years across, was compressed into a space no bigger than an atom.
I’ll tell you straight away that we have no firm understanding of the nature of the Universe at this time. That’s because the matter that filled the Universe was in such an extremely exotic state, with temperatures and pressures so stupidly high, that it’s not even worth typing out numbers for them. At these energies, our current knowledge of physics simply breaks down. We have no well-understood equation, no guiding principles, no experimental results that can tell us what exactly the Universe was up to when it was so young. But we do have a few sneaking suspicions. We’ve identified through our mathematical models and verified through experiments that the forces of nature aren’t always what they seem. At the normal, typical energies of everyday life, we experience four fundamental forces: gravity, electromagnetism, strong nuclear, and weak nuclear. But at high energies, things shuffle around a bit.
At an energy of around 246 GeV, the electromagnetic and weak nuclear forces cease to be distinct. Instead, they merge into a single super-force known (appropriately) as the electroweak force. And here's something wild: At those energies, there are only three forces of nature, not four. Once you drop below that energy, the electroweak force breaks apart into the more familiar electromagnetic and weak nuclear forces.
In physics, this splitting is called "spontaneous symmetry breaking." The unified electroweak force exhibits a deep mathematical symmetry, but that symmetry can only be sustained at high energies. In our everyday experience, that symmetry is hidden (or broken), and the electroweak’s two component forces appear to be wildly different, even though they’re really manifestations of a deeper, singular force.
Why stop there? Physicists suspect that at even higher energies, the strong nuclear force joins the party, creating a single force known as a GUT—a Grand Unified Theory. This isn’t mere idle speculation. The constants that define the strengths of the forces change with energy, and at high enough energies, they all have roughly the same strengths, signaling that unification is a viable option. Beyond that, at almost unfathomable energies, gravity is also thought to join with the others to create a Voltron of fundamental physics: a Theory of Everything. Page: 1 2 3 Next →
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Cosmology & The Universe
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Astronomers have observed a huge, mysterious dark spot on the surface of Neptune from Earth for the first time — and discovered a puzzling bright counterpart close to it.
While scientists still don't comprehend the origins of this shadowy patch on the blue surface of the distant ice giant, new observations made using the Very Large Telescope (VLT) could help shed some light on this puzzling Neptunian feature.
A dark spot on Neptune was first discovered by NASA's Voyager 2 spacecraft in 1989 when it flew by the eighth planet from the sun on its way out of the solar system. Dark spots on the surface of planets were familiar to astronomers already. Since the 1800s, they had been studying Jupiter's "Great Red Spot," a storm that has been raging on the gas giant for at least 200 years. The dark spot on Neptune was strange, however, because it disappeared after Voyager 2's observations. Then, in 2018, the Hubble Space Telescope detected several new Neptunian dark spots in both the planet's southern and northern hemispheres.
This piqued the interest of University of Oxford professor Patrick Irwin, who led a team to investigate Neptune with the VLT's Multi Unit Spectroscopic Explorer (MUSE), focusing on one of the spots in the planet’s northern hemisphere. By doing this, the researchers hoped to dismiss a previously proposed explanation, that the dark spots are caused by a clearing in clouds over the frozen surface of the ice giant.
"Dark spots are very large, 6,200 to 9,300 miles (10,000 – 15,000 km) in diameter and very mysterious,” Irwin, lead author of a paper published in the journal Science, told Live Science via email. “When the Great Dark Spot was observed by Voyager 2, there was some speculation that it might be similar to Jupiter's Great Red Spot, but we now know that Neptune's dark spots are very different. In addition to seeing a dark spot from Earth, we have also detected a deep, bright spot, labeled DBS-2019, next to the dark spot, which has never been seen before."
Still in the dark about the "spottiness" of Neptune
The team used MUSE to measure reflected light, broken down into component colors, from Neptune's dusky patch and found that this spot isn't darker than its surroundings due to the density of clouds above it.
Instead, it is because the particles in this level of the atmosphere are themselves darker, emitting light at wavelengths of 700 nanometers — around the color red in the electromagnetic spectrum.
The light spot seen by the astronomers, which is at the same level in the atmosphere as the dark spot, wasn't present in observations of Neptune conducted a few weeks before MUSE collected its data, and this seems to imply it is a short-lived feature.
"The fact that it's so close to the dark spot is interesting and suggests some connection, although what that connection is is not known," Irwin explained.
The researchers also aren't yet sure what causes the dark spots on Neptune, but Irwin said they can put forward a few viable hypotheses for the origins of these shadowy patches.
"We suggest it could be caused by the addition of darker particles from below," Irwin said. An alternative theory is that ultraviolet light is causing local heating, turning hydrogen sulfide ice straight from a solid to a gas, releasing a darker haze in the Neptunian atmosphere. "We need more observations and also more dynamical modeling to figure out what's going on here," Irwin added.
The ability to see features like this from Earth represents a massive step forward in planetary astronomy, but Irwin and the team now intend to look deeper with an instrument located off the surface of our planet, the James Webb Space Telescope (JWST).
"We're also part of a team set up to analyze recent observations of Neptune made with JWST," he concluded. "I can't wait to get cracking on these data!"
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Robert Lea is a science journalist in the U.K. who specializes in science, space, physics, astronomy, astrophysics, cosmology, quantum mechanics and technology. Rob's articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University
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Cosmology & The Universe
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The "Cosmic Cliffs" of the Carina Nebula is seen in an image divided horizontally by an undulating line between a cloudscape forming a nebula along the bottom portion and a comparatively clear upper portion, with data from NASA's James Webb Space Telescope, a revolutionary apparatus designed to peer through the cosmos to the dawn of the universe and released July 12, 2022. Speckled across both portions is a starfield, showing innumerable stars of many sizes. NASA, ESA, CSA, STScI, Webb ERO Production Team/Handout via REUTERSRegister now for FREE unlimited access to Reuters.comGREENBELT, Md., July 12 (Reuters) - Following a presidential sneak peek of a galaxy-studded image from deep in the cosmos, NASA officials gathered on Tuesday to unveil more of their initial showcase from the James Webb Space Telescope, the largest and most powerful orbital observatory ever launched.The first batch of full-color, high-resolution pictures, which took weeks to render from raw telescope data, were selected by NASA to provide compelling early images from Webb's major areas of inquiry and a preview of science missions ahead.The $9 billion infrared telescope, built for NASA by aerospace giant Northrop Grumman Corp , is expected to revolutionize astronomy by allowing scientists to peer farther than before and with greater clarity into the cosmos, to the dawn of the known universe.Register now for FREE unlimited access to Reuters.comA partnership between NASA, the European Space Agency and the Canadian Space Agency, the Webb was launched on Christmas Day, 2021, and reached its destination in solar orbit nearly 1 million miles from Earth a month later.Once there, the telescope underwent a months-long process to unfurl all of its components, including a sun shield the size of a tennis court, and to align its mirrors and calibrate its instruments.With Webb now finely tuned and fully focused, astronomers will embark on a competitively selected list of science projects exploring the evolution of galaxies, the life cycles of stars, the atmospheres of distant exoplanets and the moons of our outer solar system.The introductory assortment of pictures had been a closely guarded secret until Friday, when the space agency posted a list of five celestial subjects chosen for its big reveal on Tuesday at NASA's Goddard Space Flight Center in Maryland.Whoops and hollers from a spritely James Webb “cheer team” welcomed some 300 scientists, telescope engineers, politicians and senior officials from NASA and its international partners into a packed and lively auditorium ahead of opening remarks."I didn't know I was coming to a pep rally today," NASA Administrator James Nelson said from the stage, enthusing that Webb's "every image is a discovery."PRESIDENTIAL PEEKU.S. President Joe Biden got a jump on the unveiling with his own White House briefing on Monday to release the very first photo - an image of a galaxy cluster dubbed SMACS 0723 revealing the most detailed glimpse of the early universe recorded to date.Among the four other Webb "targets" getting their closeups on Tuesday are two enormous clouds of gas and dust blasted into space by stellar explosions to form incubators for new stars - the Carina Nebula and the Southern Ring Nebula, each thousands of light years away from Earth.The debut collection includes another galaxy cluster known as Stephan's Quintet, which was first discovered in 1877 and encompasses several galaxies described by NASA as "locked in a cosmic dance of repeated close encounters."NASA will also present Webb's first spectrographic analysis of an exoplanet - one roughly half the mass of Jupiter that lies more than 1,100 light years away - revealing the molecular signatures of filtered light passing through its atmosphere.Built to view its subjects chiefly in the infrared spectrum, Webb is about 100 times more sensitive than its 30-year-old predecessor, the Hubble Space Telescope, which operates mainly at optical and ultraviolet wavelengths.The much larger light-collecting surface of Webb's primary mirror - an array of 18 hexagonal segments of gold-coated beryllium metal - enables it to observe objects at greater distances, thus further back in time, than Hubble or any other telescope.All five of Webb's introductory targets were previously known to scientists, but NASA officials promise Webb's imagery captures its subjects in an entirely new light, literally.The SMACS 0723 image Biden released on Monday showed a 4.6 billion-year-old galaxy cluster whose combined mass acts as a "gravitational lens," distorting space to greatly magnify the light coming from more distant galaxies behind it.At least one of the faint, older specks of light appearing in the "background" of the photo - a composite of images of different wavelengths of light - dates back more than 13 billion years, Nelson said.That makes it just 800 million years younger than the Big Bang, the theoretical flashpoint that set the expansion of the known universe in motion some 13.8 billion years ago.The bejeweled-like composite photo, according to NASA, offers the "most detailed view of the early universe" as well as the "deepest and sharpest infrared image of the distant cosmos" yet taken.The thousands of galaxies appearing in the image were captured in a tiny patch of the sky roughly the size of a grain of sand held at arm's length by someone standing on Earth, Nelson said.Register now for FREE unlimited access to Reuters.comWriting and reporting by Steve Gorman in Los Angeles; Additional reporting by Joey Roulette; Editing by Raju Gopalakrishnan and Nick ZieminskiOur Standards: The Thomson Reuters Trust Principles.
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Cosmology & The Universe
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This colourful stripe of stars, gas, and dust is actually a spiral galaxy named NGC 1055. Captured here by ESO’s Very Large Telescope (VLT), this big galaxy is thought to be up to 15 percent larger in diameter than the Milky Way. NGC 1055 appears to lack the whirling arms characteristic of a spiral, as it is seen edge-on. However, it displays odd twists in its structure that were probably caused by an interaction with a large neighbouring galaxy.Spiral galaxies throughout the Universe take on all manner of orientations with respect to Earth. We see some from above (as it were) or “face-on” — a good example of this being the whirlpool-shaped galaxy NGC 1232. Such orientations reveal a galaxy’s flowing arms and bright core in beautiful detail, but make it difficult to get any sense of a three-dimensional shape.We see other galaxies, such as NGC 3521, at angles. While these tilted objects begin to reveal the three-dimensional structure within their spiral arms, fully understanding the overall shape of a spiral galaxy requires an edge-on view — such as this one of NGC 1055. When seen edge-on, it is possible to get an overall view of how stars — both new patches of starbirth and older populations — are distributed throughout a galaxy, and the “heights” of the relatively flat disc and the star-loaded core become easier to measure. Material stretches away from the blinding brightness of the galactic plane itself, becoming more clearly observable against the darker background of the cosmos.Such a perspective also allows astronomers to study the overall shape of a galaxy’s extended disc, and to study its properties. One example of this is warping, which is something we see in NGC 1055. The galaxy has regions of peculiar twisting and disarray in its disc, likely caused by interactions with the nearby galaxy Messier 77 (eso0319) [1]. This warping is visible here; NGC 1055’s disc is slightly bent and appears to wave across the core.NGC 1055 is located approximately 55 million light-years away in the constellation of Cetus (The Sea Monster). This image was obtained using the FOcal Reducer and low dispersion Spectrograph 2 (FORS2) instrument mounted on Unit Telescope 1 (Antu) of the VLT, located at ESO’s Paranal Observatory in Chile. It hails from ESO’s Cosmic Gems programme, an outreach initiative that produces images of interesting, intriguing or visually attractive objects using ESO telescopes for the purposes of education and outreach.Source: ESO press release
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Cosmology & The Universe
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By Michael J. I. Brown - Monash UniversityA telescope can reveal the beauty of the universe, such as the Moon’s craters, Saturn’s rings, and the glowing gas of the Orion nebula. But a telescope isn’t just for sightseeing – it is also a scientific instrument.If you’ve just received a telescope as a present then it’s probably better than any used by the Italian scientist Galileo Galilei (1564-1642). A small telescope with a modern camera can be more capable than professional telescopes from just a century ago.You can use your telescope to see astrophysics in action, such as the planets travelling around the Sun, see how stars have different colours and even detect worlds orbiting distant stars. At the eyepieceLook through the eyepiece of your telescope and you can retrace the beginnings of astrophysics.Galileo only had a tiny telescope with a lens just a few centimetres across. Yet he mapped the Moon, saw Saturn’s rings, and discovered Jupiter’s four largest moons – Io, Europa, Ganymede and Callisto – now known as the Galilean moons.Galileo was also persecuted for advocating the theory that the planets (including Earth) orbit around the Sun, at a time when the popular belief was that Earth was the centre of the universe.His observation of the phases of Venus are among his most compelling pieces of evidence that Earth and the other planets of our Solar System orbit the Sun. If the planets travel around the Sun, as Galileo believed, then sometimes the Sun will be (almost) between us and Venus, so we can view most of the daytime side of Venus. At other times, Venus will be between us and the Sun, and will appear as larger (since it’s closer) crescent.Venus is never too far from the Sun in the sky (indeed it’s lost in the Sun’s glare during January 2018), and is only visible near sunrise or sunset. The phases of Venus, which resemble those of the Moon, can be seen with even a small telescope.There are plenty of guides on how to find Venus (and other planets, stars, constellations, galaxies and so on) including Sky and Telescope, apps for Android and Apple devices and the free Stellarium computer software.Use any of these to find Venus, and then use your telescope to see the phases of the planet as Galileo did four centuries ago.The lives of starsUnderstanding the lives of stars was the biggest puzzle for astrophysicists during the early 20th century. One of the first clues is the fact that different stars have different colours, which tells us they have different temperatures.Even without a telescope, you can see the red star Betelgeuse and the blue star Rigel in the constellation of Orion. Betelgeuse has a surface temperature of 3,000℃, while Rigel’s surface is at 12,000℃.Why do different stars have different temperatures? Measuring the luminosities of stars with different colours provides a critical clue. Look at open star clusters such as Pleiades and you will see that (with some exceptions) the brightest stars are blue. Blue stars are often the most luminous (and most massive), and their high temperatures result from the rapid fusion of hydrogen into helium. Some blue stars are 100 times as bright as the Sun.These stars live for just millions of years, as they are using their hydrogen fuel so rapidly. In contrast, some dull red stars may live for tens of billions of years.What about the exceptions – the very luminous stars that are red, such as Betelgeuse? Some stars have run out of hydrogen in their cores, and instead fuse hydrogen in shells and/or fuse helium in their cores.These stars can become enormous in size but have (relatively) cool surface temperatures. These red giants are also approaching the end of their lives.Strange new worldsSo far your telescope has been used for simple observations of stars and planets. With the addition of some more equipment you can use your telescope to detect planets around distant stars.To do this you need a good digital camera, the ability to track a star for a few hours, and some free software for your computer.The first planets orbiting other stars were detected in the 1990s and now thousands of such worlds are known. Some of these planets orbit stars that are 100 times fainter than the unaided eye can see, and such stars are easily seen with small telescopes. If you enjoy our selection of content please consider following Universal-Sci on social media:
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Cosmology & The Universe
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For millennia, humans have been fascinated by the mysteries of the cosmos.
Unlike ancient philosophers imagining the universe's origins, modern cosmologists use quantitative tools to gain insights into the universe's evolution and structure. Modern cosmology dates back to the early 20th century, with the development of Albert Einstein's theory of general relativity.
Now, researchers from the Atacama Cosmology Telescope (ACT) collaboration have created a groundbreaking new image that reveals the most detailed map of dark matter distributed across a quarter of the entire sky, extending deep into the cosmos. What's more, it confirms Einstein's theory of how massive structures grow and bend light, over the entire 14-billion-year life span of the universe.
"We have mapped the invisible dark matter across the sky to the largest distances, and clearly see features of this invisible world that are hundreds of millions of light-years across, says Blake Sherwin, professor of cosmology at the University of Cambridge, where he leads a group of ACT researchers. "It looks just as our theories predict."
Despite making up 85% of the universe and influencing its evolution, dark matter has been hard to detect because it doesn't interact with light or other forms of electromagnetic radiation. As far as we know dark matter only interacts with gravity.
To track it down, the more than 160 collaborators who have built and gathered data from the National Science Foundation's Atacama Cosmology Telescope in the high Chilean Andes observe light emanating following the dawn of the universe's formation, the Big Bang -- when the universe was only 380,000 years old. Cosmologists often refer to this diffuse light that fills our entire universe as the "baby picture of the universe," but formally, it is known as the cosmic microwave background radiation (CMB).
The team tracks how the gravitational pull of large, heavy structures including dark matter warps the CMB on its 14-billion-year journey to us, like how a magnifying glass bends light as it passes through its lens.
"We've made a new mass map using distortions of light left over from the Big Bang," says Mathew Madhavacheril, assistant professor in the Department of Physics and Astronomy at the University of Pennsylvania. "Remarkably, it provides measurements that show that both the 'lumpiness' of the universe, and the rate at which it is growing after 14 billion years of evolution, are just what you'd expect from our standard model of cosmology based on Einstein's theory of gravity."
Sherwin adds, "our results also provide new insights into an ongoing debate some have called 'The Crisis in Cosmology,'"explaining that this crisis stems from recent measurements that use a different background light, one emitted from stars in galaxies rather than the CMB. These have produced results that suggest the dark matter was not lumpy enough under the standard model of cosmology and led to concerns that the model may be broken. However, the team's latest results from ACT were able to precisely assess that the vast lumps seen in this image are the exact right size.
"When I first saw them, our measurements were in such good agreement with the underlying theory that it took me a moment to process the results," says Cambridge Ph.D. student Frank Qu, part of the research team. "It will be interesting to see how this possible discrepancy between different measurements will be resolved."
"The CMB lensing data rivals more conventional surveys of the visible light from galaxies in their ability to trace the sum of what is out there," says Suzanne Staggs, director of ACT and Henry DeWolf Smyth Professor of Physics at Princeton University. "Together, the CMB lensing and the best optical surveys are clarifying the evolution of all the mass in the universe."
"When we proposed this experiment in 2003, we had no idea the full extent of information that could be extracted from our telescope," says Mark Devlin, the Reese Flower Professor of Astronomy at the University of Pennsylvania and the deputy director of ACT. "We owe this to the cleverness of the theorists, the many people who built new instruments to make our telescope more sensitive, and the new analysis techniques our team came up with."
ACT, which operated for 15 years, was decommissioned in September 2022. Nevertheless, more papers presenting results from the final set of observations are expected to be submitted soon, and the Simons Observatory will conduct future observations at the same site, with a new telescope slated to begin operations in 2024. This new instrument will be capable of mapping the sky almost 10 times faster than ACT.
Story Source:
Materials provided by Princeton University. Original written by Liz Fuller-Wright (Nathi Magubane from the University of Pennsylvania contributed to this story). Note: Content may be edited for style and length.
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Cosmology & The Universe
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The group building the Giant Magellan Telescope in Chile has secured a $205 million investment that will help push construction of the massive instrument over the finish line. The money will go toward the facility that will house the telescope at the Las Campanas Observatory high in Chile’s Atacama Desert. When the telescope is complete, it will be 83 feet across and will have 10 times the light collecting area and four times the spatial resolution of the Webb Space Telescope, according to a release from the Giant Magellan Telescope Organization. (For comparison, the Webb telescope is about 21 feet in diameter). The Atacama Desert is a popular place for ground-based observatories because of its remoteness, altitude, and clear skies.According to GMTO, the Magellan telescope will scrutinize exoplanet atmospheres and early galaxies and will probe the nature and roles of dark matter and dark energy in the history of the universe. The new $205 million investment comes from the international consortium of institutions that are backing the project, a group that includes Harvard University, Arizona State University, Korea Astronomy and Space Science Institute, the Smithsonian Institution, and the São Paulo Research Foundation. Part of the Giant Magellan Telescope’s innovation is the use of adaptive optics, for which it will need adaptive secondary mirrors. Adaptive optics is a technology that mitigates the effects of fluctuations in the atmosphere (the same fluctuations that cause stars to twinkle from the perspective of ground-based observers).“The idea of the adaptive optics is that you use a deformable mirror that can literally wiggle,” said Rebecca Bernstein, an astronomer at the Carnegie Institution for Science and a project scientist on the Giant Magellan Telescope, told Gizmodo in June. “You can deform that mirror to allow the light that’s reflected from it to be free of the aberrations that are caused by the atmosphere.”“That lets us get to essentially perfect, untwinkling light…very close to what you get from when you’re above the atmosphere,” Bernstein added.With its adaptive optics system, Magellan will effectively correct for atmospheric aberrations in real time as it observes the cosmos.The telescope’s first light is anticipated by the end of the decade. Currently, six of the telescope’s seven primary mirrors have been cast. The 40,000-square-foot facility needed to build the telescope’s housing structure is complete. Magellan’s first adaptive secondary mirror is underway in Europe.In tandem with the Webb Space Telescope (and potentially some other telescopes, should they secure the necessary funding to become realities), the Magellan telescope will help astronomers, astrophysicists, and planetary scientists see the universe in much sharper relief than was possible with previous generations of telescopes.More: These Telescopes Will Change the Way We See Space
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Cosmology & The Universe
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In a paper published today in Science, a global team led by Macquarie University’s Dr Stuart Ryder and Swinburne University of Technology’s Associate Professor Ryan Shannon, report on their discovery of the most ancient and distant fast radio burst located to date, about eight billion years old.
The discovery smashes the team’s previous record by 50 per cent. It confirms that fast radio bursts (FRBs) can be used to measure the “missing” matter between galaxies.
The source of the burst was shown to be a group of two or three galaxies that are merging, supporting current theories on the cause of fast radio bursts. The team also showed that eight billion years is about as far back as we can expect to see and pinpoint fast radio bursts with current telescopes.
On 10 June 2022, CSIRO’s ASKAP radio telescope on Wajarri Yamaji Country was used to detect a fast radio burst, created in a cosmic event that released, in milliseconds, the equivalent of our Sun’s total emission over 30 years.
“Using ASKAP’s array of dishes, we were able to determine precisely where the burst came from,” says Dr Ryder, the first author on the paper. “Then we used the European Southern Observatory (ESO) Very Large Telescope (VLT) in Chile to search for the source galaxy, finding it to be older and further away than any other FRB source found to date, and likely within a small group of merging galaxies.”
Named FRB 20220610A, the fast radio burst has reaffirmed the concept of weighing the Universe using data from FRBs. This was first demonstrated by the late Australian astronomer Jean-Pierre ‘J-P’ Macquart in a paper in Nature in 2020.
“J-P showed that the further away a fast radio burst is, the more diffuse gas it reveals between the galaxies,” says Dr Ryder. “This is now known as the Macquart relation. Some recent fast radio bursts appeared to break this relationship. Our measurements confirm the Macquart relation holds out to beyond half the known Universe.”
About 50 FRBs have been pinpointed to date – nearly half using ASKAP. The authors suggest we should be able to detect thousands of them across the sky, and at even greater distances.
“While we still don’t know what causes these massive bursts of energy, the paper confirms that fast radio bursts are common events in the cosmos and that we will be able to use them to detect matter between galaxies, and better understand the structure of the Universe,” says Associate Professor Shannon.
And we will soon have the tools to do so. ASKAP is currently the best radio telescope to detect and locate FRBs. The international SKA telescopes now under construction in Western Australia and South Africa will be even better at allowing astronomers to locate even older and more distant FRBs. The nearly 40-metre mirror of ESO’s Extremely Large Telescope, currently under construction in the high, dry Chilean desert will then be needed to study their source galaxies.
The project was a world-wide effort with researchers from ASTRON (Netherlands), Pontificia Universidad Católica de Valparaíso (Chile), Kavli Institute for the Physics and Mathematics of the Universe (Japan), SKA Observatory (UK), Northwestern University, UC Berkeley, and UC Santa Cruz (USA).
Australian participants were Macquarie University, Swinburne University of Technology, CSIRO, ICRAR/Curtin University, ASTRO 3D, and University of Sydney.
Current methods of estimating the mass of the Universe are giving conflicting answers and challenging the standard model of cosmology.
“If we count up the amount of normal matter in the Universe – the atoms that we are all made of – we find that more than half of what should be there today is missing,” says Associate Professor Shannon.
“We think that the missing matter is hiding in the space between galaxies, but it may just be so hot and diffuse that it's impossible to see using normal techniques.
“Fast radio bursts sense this ionised material. Even in space that is nearly perfectly empty they can ‘see’ all the electrons, and that allows us to measure how much stuff is between the galaxies.”
CSIRO's ASKAP radio telescope is situated at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory in Western Australia, about 800 kilometres north of Perth.
Currently, 16 countries are partners in the SKA Observatory, which is building two radio telescopes. SKA-Low (the low frequency telescope) – at the same site as ASKAP – will comprise 131,072 two-metre-tall antennas, while SKA-Mid (the mid frequency telescope) in South Africa will comprise 197 dishes.
The Very Large Telescope (VLT) has four eight-metre mirrors and is operated by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. Australia is a strategic partner of ESO, giving Australian astronomers access to the VLT and the opportunity to contribute new technologies to it.
Australian astronomers are also hoping to gain access to ESO’s Extremely Large Telescope when it starts operation later this decade. The ELT will be able to deliver images 15 times sharper than the Hubble Space Telescope.
Journal
Science
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
A luminous fast radio burst that probes the Universe at redshift 1
Article Publication Date
20-Oct-2023
COI Statement
No conflicting interests
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Cosmology & The Universe
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This image provided by NASA on Monday, July 11, 2022, shows galaxy cluster SMACS 0723, captured by the James Webb Space Telescope. The telescope is designed to peer back so far that scientists can get a glimpse of the dawn of the universe about 13.7 billion years ago and zoom in on closer cosmic objects, even our own solar system, with sharper focus.(Uncredited / ASSOCIATED PRESS)Our view of the universe just expanded: The first image from NASA’s new space telescope unveiled Monday is brimming with galaxies and offers the deepest look of the cosmos ever captured.The first image from the $10 billion James Webb Space Telescope is the farthest humanity has ever seen in both time and distance, closer to the dawn of time and the edge of the universe. That image will be followed Tuesday by the release of four more galactic beauty shots from the telescope’s initial outward gazes.The “deep field” image released at a White House event is filled with lots of stars, with massive galaxies in the foreground and faint and extremely distant galaxies peeking through here and there. Part of the image is light from not too long after the Big Bang, which was 13.8 billion years ago.“We’re going to give humanity a new view of the cosmos,” NASA Administrator Bill Nelson told reporters last month in a briefing. “And it’s a view that we’ve never seen before.”This image provided by NASA on Monday, July 11, 2022, shows galaxy cluster SMACS 0723, captured by the James Webb Space Telescope. The telescope is designed to peer back so far that scientists can get a glimpse of the dawn of the universe about 13.7 billion years ago and zoom in on closer cosmic objects, even our own solar system, with sharper focus. (NASA/ESA/CSA via AP)(Uncredited / ASSOCIATED PRESS)The images on tap for Tuesday include a view of a giant gaseous planet outside our solar system, two images of a nebula where stars are born and die in spectacular beauty and an update of a classic image of five tightly clustered galaxies that dance around each other.The world’s biggest and most powerful space telescope rocketed away last December from French Guiana in South America. It reached its lookout point 1 million miles (1.6 million kilometers) from Earth in January. Then the lengthy process began to align the mirrors, get the infrared detectors cold enough to operate and calibrate the science instruments, all protected by a sunshade the size of a tennis court that keeps the telescope cool.The plan is to use the telescope to peer back so far that scientists will get a glimpse of the early days of the universe about 13.7 billion years ago and zoom in on closer cosmic objects, even our own solar system, with sharper focus.Webb is considered the successor to the highly successful, but aging Hubble Space Telescope. Hubble has stared as far back as 13.4 billion years. It found the light wave signature of an extremely bright galaxy in 2016. Astronomers measure how far back they look in light-years with one light-year being 5.8 trillion miles (9.3 trillion kilometers).“Webb can see backwards in time to just after the Big Bang by looking for galaxies that are so far away that the light has taken many billions of years to get from those galaxies to our telescopes,” said Jonathan Gardner, Webb’s deputy project scientist said during the media briefing.How far back did that first image look? Over the next few days, astronomers will do intricate calculations to figure out just how old those galaxies are, project scientist Klaus Pontoppidan said last month.The deepest view of the cosmos “is not a record that will stand for very long,” Pontoppidan said, since scientists are expected to use the telescope to go even deeper.Thomas Zurbuchen, NASA’s science mission chief said when he saw the images he got emotional and so did his colleagues: “It’s really hard to not look at the universe in new light and not just have a moment that is deeply personal.”At 21 feet (6.4 meters), Webb’s gold-plated, flower-shaped mirror is the biggest and most sensitive ever sent into space. It’s comprised of 18 segments, one of which was smacked by a bigger than anticipated micrometeoroid in May. Four previous micrometeoroid strikes to the mirror were smaller. Despite the impacts, the telescope has continued to exceed mission requirements, with barely any data loss, according to NASA.NASA is collaborating on Webb with the European and Canadian space agencies.“I’m now really excited as this dramatic progress augurs well for reaching the ultimate prize for many astronomers like myself: pinpointing “Cosmic Dawn” — the moment when the universe was first bathed in starlight,” Richard Ellis, professor of astrophysics at University College London, said via email.Get the breaking newsGet email alerts on breaking news stories as soon as they happen.By signing up you agree to our privacy policyMost Popular on DallasNews.com12345
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Cosmology & The Universe
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Research by the Atacama Cosmology Telescope collaboration has culminated in a significant breakthrough in understanding the evolution of the universe.
For millennia, humans have been fascinated by the mysteries of the cosmos.
Unlike ancient philosophers imagining the universe’s origins, modern cosmologists use quantitative tools to gain insights into its evolution and structure. Modern cosmology dates back to the early 20th century, with the development of Albert Einstein’s theory of general relativity.
Now, researchers from the Atacama Cosmology Telescope (ACT) collaboration have submitted a set of papers to The Astrophysical Journal featuring a groundbreaking new map of dark matter distributed across a quarter of the sky, extending deep into the cosmos, that confirms Einstein’s theory of how massive structures grow and bend light over the 14-billion-year life span of the universe.
The new map uses light from the cosmic microwave background (CMB) essentially as a backlight to silhouette all the matter between us and the Big Bang.
“It’s a bit like silhouetting, but instead of just having black in the silhouette, you have texture and lumps of dark matter, as if the light were streaming through a fabric curtain that had lots of knots and bumps in it,” said Suzanne Staggs, director of ACT and Henry DeWolf Smyth Professor of Physics at Princeton University. “The famous blue and yellow CMB image [from 2003] is a snapshot of what the universe was like in a single epoch, about 13 billion years ago, and now this is giving us the information about all the epochs since.”
“It’s a thrill to be able to see the invisible, to uncover this scaffold of dark matter that holds our visible star-filled galaxies,” said Jo Dunkley, a professor of physics and astrophysical sciences, who leads the analysis for ACT. “In this new image, we can see directly the invisible cosmic web of dark matter that surrounds and connects galaxies.”
“Usually, astronomers can only measure light, so we see how galaxies are distributed across the universe; these observations reveal the distribution of mass, so primarily show how the dark matter is distributed through our universe,” said David Spergel, Princeton’s Charles A. Young Professor of Astronomy on the Class of 1897 Foundation, Emeritus, and the president of the Simons Foundation.
“We have mapped the invisible dark matter distribution across the sky, and it is just as our theories predict,” said co-author Blake Sherwin, a 2013 Ph.D. alumnus of Princeton and a professor of cosmology at the University of Cambridge, where he leads a large group of ACT researchers. “This is stunning evidence that we understand the story of how structure in our universe formed over billions of years, from just after the Big Bang to today.’
He added: “Remarkably, 80% of the mass in the universe is invisible. By mapping the dark matter distribution across the sky to the largest distances, our ACT lensing measurements allow us to clearly see this invisible world.”
“When we proposed this experiment in 2003, we had no idea the full extent of information that could be extracted from our telescope,” said Mark Devlin, the Reese Flower Professor of Astronomy at the University of Pennsylvania and the deputy director of ACT, who was a Princeton postdoc from 1994-1995. “We owe this to the cleverness of the theorists, the many people who built new instruments to make our telescope more sensitive, and the new analysis techniques our team came up with.” This includes a sophisticated new model of ACT’s instrument noise by Princeton graduate student Zach Atkins.
Despite making up most of the universe, dark matter has been hard to detect because it doesn’t interact with light or other forms of electromagnetic radiation. As far as we know, dark matter only interacts with gravity.
To track it down, the more than 160 collaborators who have built and gathered data from the National Science Foundation’s Atacama Cosmology Telescope in the high Chilean Andes observed light emanating following the dawn of the universe’s formation, the Big Bang — when the universe was only 380,000 years old. Cosmologists often refer to this diffuse CMB light that fills our entire universe as the “baby picture of the universe.”
The team tracked how the gravitational pull of massive dark matter structures can warp the CMB on its 14-billion-year journey to us, just as antique, lumpy windows bend and distort what we can see through them.
“We’ve made a new mass map using distortions of light left over from the Big Bang,” said Mathew Madhavacheril, a 2016-2018 Princeton postdoc who is the lead author of one of the papers and an assistant professor in physics and astronomy at the University of Pennsylvania. “Remarkably, it provides measurements that show that both the ‘lumpiness’ of the universe, and the rate at which it is growing after 14 billion years of evolution, are just what you’d expect from our standard model of cosmology based on Einstein’s theory of gravity.”
Sherwin added, “Our results also provide new insights into an ongoing debate some have called ‘The Crisis in Cosmology.’” This “crisis” stems from recent measurements that use a different background light, one emitted from stars in galaxies rather than the CMB. These have produced results that suggest the dark matter was not lumpy enough under the standard model of cosmology and led to concerns that the model may be broken. However, the ACT team’s latest results precisely assessed that the vast lumps seen in this image are the exact right size.
“While earlier studies pointed to cracks in the standard cosmological model, our findings provide new reassurance that our fundamental theory of the universe holds true,” said Frank Qu, lead author of one of the papers and a Cambridge graduate student as well as a former Princeton visiting researcher.
“The CMB is famous already for its unparalleled measurements of the primordial state of the universe, so these lensing maps, describing its subsequent evolution, are almost an embarrassment of riches,” said Staggs, whose team built the detectors that gathered this data over the past five years. “We now have a second, very primordial map of the universe. Instead of a ‘crisis,’ I think we have an extraordinary opportunity to use these different data sets together. Our map includes all of the dark matter, going back to the Big Bang, and the other maps are looking back about 9 billion years, giving us a layer that is much closer to us. We can compare the two to learn about the growth of structures in the universe. I think is going to turn out to be really interesting. That the two approaches are getting different measurements is fascinating.”
ACT, which operated for 15 years, was decommissioned in September 2022. Nevertheless, more papers presenting results from the final set of observations are expected to be submitted soon, and the Simons Observatory will conduct future observations at the same site, with a new telescope slated to begin operations in 2024. This new instrument will be capable of mapping the sky almost 10 times faster than ACT.
Of the co-authors on the ACT team’s series of papers, 56 are or have been Princeton researchers. More than 20 scientists who were junior researchers on ACT while at Princeton are now faculty or staff scientists themselves. Lyman Page, Princeton’s James S. McDonnell Distinguished University Professor in Physics, was the former principal investigator of ACT.
This research will be presented at “Future Science with CMB x LSS,” a conference running from April 10-14 at Yukawa Institute for Theoretical Physics, Kyoto University. The pre-print articles highlighted here will appear on the open-access arXiv.org. They have been submitted to the Astrophysical Journal. This work was supported by the U.S. National Science Foundation (AST-0408698, AST-0965625 and AST-1440226 for the ACT project, as well as awards PHY-0355328, PHY-0855887 and PHY-1214379), Princeton University, the University of Pennsylvania, and a Canada Foundation for Innovation award. Team members at the University of Cambridge were supported by the European Research Council.
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Cosmology & The Universe
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The James Webb Space Telescope prior to launch. The telescope is designed to peer back so far that scientists will get a glimpse of the dawn of the universe about 13.7 billion years ago and zoom in on closer cosmic objects with sharper focus.Laura Betz/AP file Allison Strom sent a note on her astronomer text chain reading “Holy Jesus! Did you see that?” after the first images taken by the James Webb Space Telescope were revealed this week.Strom, an assistant professor of physics and astronomy at Northwestern University, is pumped up. And for good reason. Allison Strom, an assistant professor of physics and astronomy at Northwestern UniversityProvided She’s basically next in a long line of astronomers who got permission to use the telescope.She’ll get the chance to focus the device on a tiny patch of the cosmos to study what galaxies were made of billions of years ago when the universe was like a teenager.“You know, extremely messy, trying to figure out what they want to do with their lives,” Strom joked.Her project has been dubbed CECILIA (Chemical Evolution Constrained using Ionized Lines in Interstellar Aurorae) and is an acronym designed to fit the name of Cecilia Payne-Gaposchkin, one of the first women to earn a doctorate in astronomy.Emails from Strom to her team occasionally include a doctored photo of the pioneering astronomer wearing a little party hat.At some point in the next three weeks, the Webb telescope will do Strom’s bidding for a window of 40 hours, and then the fun begins for her and her colleagues who will analyze the data.In the meantime, Strom, 33, hopes to find a reasonably priced condo or rent an apartment somewhere in Ravenswood or Lake View. She’s a new hire and moving from New Jersey, where she was a postdoctoral fellow at Princeton University.She’s one of several astronomers at Northwestern and the University of Chicago who have been granted coveted time with the telescope — a $10 billion device that launched Christmas Day and traveled a million miles before sticking the landing in a cosmic parking lot known as L2, where it will orbit the sun.The risky process was the source of countless hours of lost sleep for scientists the world over. But it was a success.“The telescope works, and it works brilliantly. Our knowledge about the universe is about to take a giant leap forward,” said University of Chicago astronomy professor Jacob Bean, who viewed the first images revealed Monday by President Joe Biden from the comfort of his couch in Hyde Park. Jacob Bean, University of Chicago astronomy professor John Zich “I just had the biggest grin on my face as I sat there,” said Bean, 42. “It’s just fantastic. It’s the moment of a lifetime, the moment of my professional career to use the telescope and analyze the data.”He is a co-leader of a team of about 150 scientists who are in the process of receiving data from Webb that will shed light on exoplanets, or planets that orbit stars outside of Earth’s solar system.Their goal is to look for clues about the composition of them, how cold or warm they are, and whether they are habitable.Bean, who grew up in rural Georgia, said the exoplanet field of research was viewed as a bit of a kooky sideshow as recently as 10 years ago.“But now to reach the point where it’s been chosen for use by NASA’s flagship telescope, it shows how far our small group of people have come,” he said. “Everything we’ve planned and worked for has become a reality.” This image released by NASA on Tuesday, July 12, 2022, shows the edge of a nearby, young, star-forming region NGC 3324 in the Carina Nebula. Captured in infrared light by the Near-Infrared Camera (NIRCam) on the James Webb Space Telescope, this image reveals previously obscured areas of star birth, according to NASA.NASA, ESA, CSA, and STScI via AP Editor’s note: This article was corrected to say Allison Strom was a postdoctoral fellow at Princeton University.
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Cosmology & The Universe
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GREENBELT, Md. (AP) — NASA on Tuesday unveiled a new batch of images from its new powerful space telescope, including a foamy blue and orange shot of a dying star.The first image from the $10 billion James Webb Space Telescope was released Monday at the White House — a jumble of distant galaxies that went deeper into the cosmos than humanity has ever seen.The four additional photos released Tuesday included more cosmic beauty shots.With one exception, the latest images showed parts of the universe seen by other telescopes. But Webb’s sheer power, distant location off Earth and use of the infrared light spectrum showed them in new light.“Every image is a new discovery and each will give humanity a view of the humanity that we’ve never seen before,’’ NASA Administrator Bill Nelson said Tuesday, rhapsodizing over images showing “the formation of stars, devouring black holes.”Webb's use of the infrared light spectrum allows the telescope to see through the cosmic dust and “see light from faraway light from the corners of the universe,” he said.“We’ve really changed the understanding of our universe,” said European Space Agency director general Josef Aschbacher.The European and Canadian space agencies joined NASA in building the powerful telescope.On tap Tuesday:— The Southern Ring Nebula, which is sometimes called “eight-burst.’ About 2,500 light-years away, it shows an expanding cloud of gas surrounding a dying star. A light-year is 5.8 trillion miles.The dimmer star at the center of this scene has been sending out rings of gas and dust for thousands of years in all directions.NASA/Getty— Carina Nebula, one of the bright stellar nurseries in the sky, about 7,600 light-years away.This image combined the capabilities of the James Webb Space Telescope's two cameras to create a never-before-seen view of a star-forming region in the Carina Nebula.Space Telescope Science Institute Office of Public Outreach/Associated Press— Five galaxies in a cosmic dance, 290 million light-years away. Stephan’s Quintet was first seen 225 years ago in the constellation Pegasus.NASA's James Webb Space Telescope revealed Stephans Quintet, a visual grouping of five galaxies, in a new light. This enormous mosaic is Webb's largest image to date, covering about one-fifth of the Moon's diameter.NASA/GettyStephan's Quintet, a visual grouping of five galaxies captured by the Webb Telescope's Mid-Infrared Instrument (MIRI).Space Telescope Science Institute Office of Public Outreach/Associated Press— A blueish giant planet called WASP-96b. It’s about the size of Saturn and is 1,150 light-years away. A gas planet, it’s not a candidate for life elsewhere but a key target for astronomers.NASA's James Webb Space Telescope has captured the distinct signature of water, along with evidence for clouds and haze, in the atmosphere surrounding a hot, puffy gas giant planet orbiting a distant Sun-like star.NASA/GettyThe images were released one-by-one at an event at NASA’s Goddard Space Center that included cheerleaders with pompoms the color of the telescope’s golden mirrors.The world’s biggest and most powerful space telescope rocketed away last December from French Guiana in South America. It reached its lookout point 1 million miles (1.6 million kilometers) from Earth in January. Then the lengthy process began to align the mirrors, get the infrared detectors cold enough to operate and calibrate the science instruments, all protected by a sunshade the size of a tennis court that keeps the telescope cool.Webb is considered the successor to the highly successful, but aging Hubble Space Telescope.
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Cosmology & The Universe
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NASA released some of the very first images taken by the James Webb Space Telescope on July 12, 2022. They mark the beginning of the next era in astronomy as Webb – the largest space telescope ever built – offers scientific data that will help answer questions about the earliest moments of the universe and allow astronomers to study exoplanets in greater detail than ever before.
Watch the release in the player above.
But it has taken nearly eight months of travel, setup, testing and calibration to make sure this most valuable of telescopes is ready for prime time. Marcia Rieke, an astronomer at the University of Arizona and the scientist in charge of one of Webb’s four cameras, explains what she and her colleagues have been doing to get this telescope up and running.
READ MORE: Here’s the deepest, clearest infrared image of the universe ever produced
What’s happened since the telescope launched?
After the successful launch of the James Webb Space Telescope on Dec. 25, 2021, the team began the long process of moving the telescope into its final orbital position, unfolding the telescope and – as everything cooled – calibrating the cameras and sensors onboard.
The launch went as smoothly as a rocket launch can go. One of the first things my colleagues at NASA noticed was that the telescope had more remaining fuel onboard than predicted to make future adjustments to its orbit. This will allow Webb to operate for much longer than the mission’s initial 10-year goal.
The first task during Webb’s monthlong journey to its final location in orbit was to unfold the telescope. This went along without any hitches, starting with the white-knuckle deployment of the sun shield that helps cool the telescope, followed by the alignment of the mirrors and the turning on of sensors.
WATCH: Biden offers first peek of historic image from James Webb Space Telescope
Once the sun shield was open, our team began monitoring the temperatures of the four cameras and spectrometers onboard, waiting for them to reach temperatures low enough so that we could start testing each of the 17 different modes in which the instruments can operate. The NIRCam on Webb was the first instrument to go online and helped align the 18 mirror segments. NASA Goddard Space Center/Wikimedia Commons
What did you test first?
The cameras on Webb cooled just as the engineers predicted, and the first instrument the team turned on was the Near Infrared Camera – or NIRCam. NIRCam is designed to study the faint infrared light produced by the oldest stars or galaxies in the universe. But before it could do that, NIRCam had to help align the 18 individual segments of Webb’s mirror.
Once NIRCam cooled to minus 280 F, it was cold enough to start detecting light reflecting off of Webb’s mirror segments and produce the telescope’s first images. The NIRCam team was ecstatic when the first light image arrived. We were in business!
These images showed that the mirror segments were all pointing at a relatively small area of the sky, and the alignment was much better than the worst-case scenarios we had planned for.
Webb’s Fine Guidance Sensor also went into operation at this time. This sensor helps keep the telescope pointing steadily at a target – much like image stabilization in consumer digital cameras. Using the star HD84800 as a reference point, my colleagues on the NIRCam team helped dial in the alignment of the mirror segments until it was virtually perfect, far better than the minimum required for a successful mission.
What sensors came alive next?
As the mirror alignment wrapped up on March 11, the Near Infrared Spectrograph – NIRSpec – and the Near Infrared Imager and Slitless Spectrograph – NIRISS – finished cooling and joined the party.
NIRSpec is designed to measure the strength of different wavelengths of light coming from a target. This information can reveal the composition and temperature of distant stars and galaxies. NIRSpec does this by looking at its target object through a slit that keeps other light out.
WATCH: NASA’s James Webb telescope poised to launch new golden age of astronomy
NIRSpec has multiple slits that allow it to look at 100 objects at once. Team members began by testing the multiple targets mode, commanding the slits to open and close, and they confirmed that the slits were responding correctly to commands. Future steps will measure exactly where the slits are pointing and check that multiple targets can be observed simultaneously.
NIRISS is a slitless spectrograph that will also break light into its different wavelengths, but it is better at observing all the objects in a field, not just ones on slits. It has several modes, including two that are designed specifically for studying exoplanets particularly close to their parent stars.
So far, the instrument checks and calibrations have been proceeding smoothly, and the results show that both NIRSpec and NIRISS will deliver even better data than engineers predicted before launch. The MIRI camera, image on the right, allows astronomers to see through dust clouds with incredible sharpness compared with previous telescopes like the the Spitzer Space Telescope, which produced the image on the left. NASA/JPL-Caltech (left), NASA/ESA/CSA/STScI (right)/Flickr, CC BY
What was the last instrument to turn on?
The final instrument to boot up on Webb was the Mid-Infrared Instrument, or MIRI. MIRI is designed to take photos of distant or newly formed galaxies as well as faint, small objects like asteroids. This sensor detects the longest wavelengths of Webb’s instruments and must be kept at minus 449 F – just 11 degrees F above absolute zero. If it were any warmer, the detectors would pick up only the heat from the instrument itself, not the interesting objects out in space. MIRI has its own cooling system, which needed extra time to become fully operational before the instrument could be turned on.
Radio astronomers have found hints that there are galaxies completely hidden by dust and undetectable by telescopes like Hubble that captures wavelengths of light similar to those visible to the human eye. The extremely cold temperatures allow MIRI to be incredibly sensitive to light in the mid-infrared range which can pass through dust more easily. When this sensitivity is combined with Webb’s large mirror, it allows MIRI to penetrate these dust clouds and reveal the stars and structures in such galaxies for the first time.
What’s next for Webb?
As of June 15, 2022, all of Webb’s instruments are on and have taken their first images. Additionally, four imaging modes, three time series modes and three spectroscopic modes have been tested and certified, leaving just three to go.
On July 12, NASA plans to release a suite of teaser observations that illustrate Webb’s capabilities. These will show the beauty of Webb imagery and also give astronomers a real taste of the quality of data they will receive.
After July 12, the James Webb Space Telescope will start working full time on its science mission. The detailed schedule for the coming year hasn’t yet been released, but astronomers across the world are eagerly waiting to get the first data back from the most powerful space telescope ever built.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Cosmology & The Universe
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New data from the Dark Energy Survey and South Pole Telescope suggest that the universe is less ‘clumpy’ than the standard cosmological model predicts. This has triggered speculation about new forces and insights into the nature of dark matter and dark energy. But this entire project is deeply misguided. We already have robust observations contradicting the standard cosmological model, showing that the universe is in fact more, not less, ‘clumpy’ than we thought. It’s about time the cosmology community faced these results, argue Pavel Kroupa and Moritz Haslbauer.
A recent publication in the journal Physical Review D with about 156 co-authors suggests the distribution of matter to be smoother than expected, based on the predictions of the standard model of cosmology [1]. This new data release by the Dark Energy Survey, was based on the findings of a telescope in Chile that measured the tiny distortions of the images of relatively nearby galaxy images, caused by their light being diverted due to the gravitational pull of foreground matter. The team also employed observations from the South Pole Telescope to measure distortions of the cosmic microwave background (CMB), again due to the uneven distribution of foreground matter. The CMB suggests that matter was nearly evenly distributed in the universe, about 400,000 years after the Big Bang. As time progressed and the universe aged and expanded, matter began to clump together under the influence of gravity. But the clumping observed by the South Pole Telescope also did not accord with the predictions of the standard cosmological model.
The cosmology community is already speculating on the back of these results, even though they are not statistically significant, imagining new forces and theories about the nature of dark matter and dark energy. But these new findings, while calling for tweaks in the standard cosmological model, fly in the face of a series of more robust observations that suggest that the standard cosmological model is not fit for purpose. Dark matter and dark energy are fictions with no empirical backing, and range of recent observations, including by the James Webb Telescope, are increasingly showing to anyone willing to see that the universe doesn’t look or behave the way the standard cosmological model predicts. It’s about time the cosmology community gave up on this theory rather than digging itself into a deeper hole filled with speculation and fantasy.
The standard model of cosmology assumes Einsteinian gravitation to be valid everywhere in the universe, and in order to match observational data, it has to postulate the existence of dark matter, 5 times the amount of normal matter, as well as dark energy, which supposedly comprises some 75 per cent of all of the energy content in the universe. The standard cosmological model also assumes the cosmological principle, according to which the universe looks the same in every direction. Using these assumptions, scientists can calculate how the initial smoothness of the cosmic microwave background evolved into an increasingly clumpy and moving distribution of matter, made of filaments, galaxy clusters and galaxies. The measurement of this process allows astronomers to test if the model is correct.
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Observations tell us that the Universe is structured on every scale, amounting to a falsification of the standard model of cosmology with extreme statistical confidence
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The recent observations and analysis of the Dark Energy Survey and South Pole Telescope data are incredibly complicated. The analysis needs to make assumptions on the statistical shape and orientation of galaxies in order to extract the evidence for extremely weak image distortions through gravitational lensing from fore-ground galaxies which requires a description of their distribution. Finding evidence for and measuring the distortions of the peaks in the CMB caused by gravitational lensing from the foreground matter distribution essentially involves the calculation of the lensing of a random field by a random field. For this, the not-distorted CMB fluctuation pattern needs to be known. And this requires a model of the CMB that is otherwise not testable. The results by the Dark Energy Survey and South Pole Telescope collaborations, that the measured distribution of matter is smoother than expected from the standard model, is a problem, not just for the standard model itself, but also for the research projects and collaborations that rely on it.
To begin with, we need to be careful to not over-interpret the results published by the DES and SPT collaborations in terms of possible physics. The indication of too much smoothness is not yet statistically significant enough at present to warrant a discussion about the need for a new physics.
What we do we know about the smoothness, or the lack thereof, of the matter distribution in the universe, from more direct measurements, is that it’s much clumpier and faster-moving in parts than the standard cosmological model allows. In fact, the observations tell us that the Universe is structured on every scale, amounting to a falsification of the standard model of cosmology with extreme (more than 5 sigma) statistical confidence. A serious physicist would never again touch a theory that has been ruled out at such a significance level.
All this was already covered in a previous article for the IAI [2]. A recent publication [3] finds that the motion of the Local Group towards the CMB seems to have a different velocity and direction to the same motion relative to very distant quasars and active galactic nuclei that should, however, yield a very comparable reference frame to that provided by the CMB. This indicates Gpc-scale matter flows and inhomogeneities. Similarly, but independently, the analysis of 570 galaxy clusters shows a strong indication for a bulk motion of matter over scales of hundreds of Mpc with a velocity of nearly 1000 km/s [4]. These are numbers that are entirely impossible in the comparatively smooth standard model. Another interesting recent observation by us is that the southern hemisphere has more early-type galaxies (i.e., rounder galaxies with less star formation) than the northern hemisphere which has more star forming, disk-like galaxies [5]. This result is statistically extremely significant. Although we speculated that this may be due to some yet unknown bias in the galaxy catalogues, we also note that the overabundance of early-type galaxies in the southern hemisphere approximately correlates with the CMB having more power and a higher temperature in the southern hemisphere [6, 7, 8]. At face value, this seems to suggest that the one side of the Universe had more power, was warmer and resulted in a different population of galaxies than the other side, violating the cosmological principle.
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Given the above well-documented and published evidence, indicating significant matter lumpiness on all scales and at all times, why does the cosmological community appear to largely ignore it?
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This all sounds crazy from the viewpoint of the dominant theory, standard cosmological model. But the data, including the recent observations by the James Webb Space Telescope, indicate that the very early Universe was a lot clumpier than the standard model allows. Massive galaxies have been observed fully formed merely a few hundred years after the Big Bang, a lot earlier than previously thought possible [9]. The data thus robustly falsify the cosmological principle. While the same laws of physics may apply in every corner of the universe, the universe itself it is not the same everywhere.
Given the above well-documented and published evidence, indicating significant matter lumpiness on all scales and at all times, why does the cosmological community appear to largely ignore it? More specifically, and problematically, for the case in hand, why do the Dark Energy Survey and South Pole Telescope collaborations not take the documented inhomogeneities into account? Or worse, why does their analysis yield an observed universe that is, if anything, even smoother than the standard model predicts, and is thus in total contradiction with the real observed Universe which is significantly clumpier than the supposedly real universe that the Dark Energy Survey and South Pole Telescope collaborations are claiming to be measuring? Does this indicate some serious problem, some total failure of weak lensing analysis?
Driven by the unexpected smoother-than-the-smooth standard model results, the scientific establishment is already fired up with speculations about non-standard physics of "standard" dark matter and dark energy. It seems as if most of the cosmological community is just waiting to jump on any indication for additional dark physics in the dark sector, knowing full-well that any speculation might produce many papers (they say, after all, "publish or perish") that have a content that can practically never be checked to be of any physical relevance, by the dark nature of dark physics in the dark sector. Maybe this is where the modern theoretical physicist, being perhaps arrogant through mathematical prowess, fails the basic mission that must be the advancement of understanding nature rather than contriving increasingly complicated mathematical theories? Sabine Hossenfelder [10] has already eloquently touched on this issue. Thus, rather than discarding the standard cosmological model, our scientific establishment is digging itself ever deeper into the speculative fantasy realm, losing sight of and also grasp of reality in what appears to be a maelstrom of insanity.
References
[1] "Joint analysis of DES Year 3 data and CMB lensing from SPT and Planck III: Combined cosmological constraints", DES and SPT collaboration:
T. M. C. Abbott et al. (DES and SPT Collaborations)
Phys. Rev. D 107, 023531
[2] "Dark Matter Doesn't Exist", Kroupa, P., iai, 12th July 2022
[3] "A Challenge to the Standard Cosmological Model", Secrest, N. J., et al. 2022, ApJ 937, 31
[4] "Cosmological implications of the anisotropy of ten galaxy cluster scaling relations", Migkas, K., et al. 2021, A&A 649, 151
[5] "Anisotropy in the all-sky distribution of galaxy morphological types", Javanmardi, B., Kroupa, P. 2017, A&A 597, 120
[6] "Asymmetries in the Cosmic Microwave Background Anisotropy Field", Eriksen, H. K., et al. 2004, ApJ 650, 14
[7] "Hemispheric asymmetry and cold spot in the Cosmic Microwave Background", Planck 2013
https://sci.esa.int/web/planck/-/51559-hemispheric-asymmetry-and-cold-spot-in-the-cosmic-microwave-background
[8] "CMB anomalies after Planck", Schwarz, D., et al. 2016, CQGra 33, 4001
[9] "Has JWST Already Falsified Dark-matter-driven Galaxy Formation?", Haslbauer, M., etal. 2022, ApJ 939, 31
[10] "Lost in Math : How Beauty Leads Physics Astray", Hossenfelder, S., 2018. New York: Basic Books. OCLC: 1005547825. ISBN: 9780465094257.
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Cosmology & The Universe
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Astronomers presented us with a mysterious video Wednesday: footage decked with lime green smudges steadily evolving on a dark background. But right at the center of this recording, one smudge isn't like the others. It's the brightest neon blob of all, and it enhances with each frame. What you're seeing is proof that some 20 billion years ago an ultrapowerful neutron star collided with a weaker star, spitting out an explosive, short-lived gamma ray burst, rippling gravitational waves across the cosmos and diffusing surrounding space with a potent afterglow. It was a shattering merger that occurred when the universe was at just 40% its current age, and our remarkable view of its incident is courtesy of the world's largest radio telescope, the Atacama Large Millimeter/submillimeter Array situated in Chile. More specifically, ALMA is a combination of 66 radio telescopes spread out across the high-altitude Chilean Andes. And they work together to bring us data about our universe's violent side."Afterglows for short bursts are very difficult to come by, so it was spectacular to catch this event shining so brightly," Wen-fai Fong, an astronomer at Northwestern University and principal investigator of the ALMA program, said in a statement. "This surprising discovery opens up a new area of study, as it motivates us to observe many more of these with ALMA and other telescope arrays in the future."The first-ever time-lapse footage of a short gamma ray burst's afterglow captured in millimeter wavelengths by ALMA ALMA (ESO/NAOJ/NRAO), T. Laskar (Utah), S. Dagnello (NRAO/AUI/NSF) Details of Fong and fellow researchers' findings are soon to be published in an upcoming issue of The Astrophysical Journal Letters. For now, a preprint is available to view on arXiv. An incomprehensible force of natureShort-lived gamma ray bursts, like this one formally dubbed GRB 211106A, are some of the most intense, mind-bendingly strong explosions known to science. But in contrast to longer-lived ones, they remained a mystery due to their fleeting nature, until 2005, when NASA's Neil Gehrels Swift Observatory collected data about one for the first time.In a matter of seconds, these cosmic spurts can emit more energy than our sun will emit in its entire lifetime. Though such extremity makes sense for them, because these phenomena stem from binary star collisions that involve at least one neutron star, a hyperdense ball of gas that rivals even black holes in gravitational monstrosity. Just one tablespoon of a neutron star would equal something like the weight of Mount Everest. A still of two neutron stars about to merge. Replace one with a normal star and you might be imagining what happened long ago with the cosmic subjects of this new study. NASA's Goddard Space Flight Center/CI Lab "These mergers occur because of gravitational wave radiation that removes energy from the orbit of the binary stars, causing the stars to spiral in toward each other," Tanmoy Laskar, lead author of the study and an astronomer at Radboud University, said in a statement. "The resulting explosion is accompanied by jets moving at close to the speed of light. When one of these jets is pointed at Earth, we observe a short pulse of gamma-ray radiation or a short-duration GRB."That's the vivid green blip we see in the recent burst's recording.ALMA's expertiseThe fact that the study team used ALMA to locate this particular burst marks the very first time such an event has been captured in millimeter wavelengths, the Chilean 'scope's specialty. Although this dramatic collision had already been studied with NASA's Hubble Space Telescope, it was seen only under the guise of optical and infrared light wavelengths. With those wavelengths, Hubble could basically only estimate information about the faraway galaxy this merger happened within, but not too much about afterglow that followed. Even if the agency's groundbreaking James Webb Space Telescope one day embarks on a mission to investigate GRB 21106A, it'll be restricted to infrared light wavelengths too, though on a much wider spectrum.ALMA, on the other hand, could see something different than what Hubble did with its millimeter wavelengths -- it indeed captured GRB 21106A's afterglow. And after some deliberation, the new study's team recognized that this short gamma ray burst's afterglow is among the most luminescent ever seen. This view shows several of the ALMA antennas and central regions of the Milky Way above. ESO/B. Tafreshi "What makes GRB 211106A so special is it's not only the first short-duration GRB that we detected in this wavelength, but also, thanks to the millimeter and radio detection, we could measure the opening angle of the jet," Rouco Escorial, study co-author and an astronomer at Northwestern University, said in a statement. Down the line, such information could prove essential to inferring rates of such GRBs in our universe and comparing them with the rates of double neutron star mergers and perhaps even black hole mergers."ALMA shatters the playing field in terms of its capabilities at millimeter wavelengths and has enabled us to see the faint, dynamic universe in this type of light for the first time," Fong said. "After a decade of observing short GRBs, it is truly amazing to witness the power of using these new technologies to unwrap surprise gifts from the universe."
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Cosmology & The Universe
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Our picture of cosmic evolution could be thrown into doubt by the discovery of a massive galaxy that seems to lack dark matter.
Dark matter, which accounts for around 85% of the matter in the universe, seems to be absent from the galaxy NGC 1277, part of the Perseus Cluster of galaxies. The galaxy, located 240 million light-years from Earth, is the first Milky Way-sized conglomeration of stars, planets, dust and gas found to be missing dark matter.
"This result does not fit in with the currently accepted cosmological models, which include dark matter," the leader behind the discovery and University of La Laguna researcher Sebastién Comerón said in a statement.
Related: What is dark matter?
Dark matter is effectively invisible because it does not interact with light like the everyday matter that composes stars, planets, and us. Its presence can be inferred by its gravitational interactions, however. The existence of this shadowy substance was first posited when astronomers observed massive galaxies rotating so fast they would fly apart if it weren't for the gravitational influence of some unseen mass holding them together.
This fact resulted in scientists theorizing that all large galaxies are wrapped in an envelope of dark matter, and this has become an important assumption in the development of theories of galactic evolution. But the discovery of a galaxy that appears to haven no dark matter challenges that assumption.
Examining an anti-social relic galaxy
Considered a cosmic relic, NGC 1277 is unusual among galaxies because it has had little interaction with other surrounding galaxies. Galaxies like this are considered to be the remains of giant galaxies that existed in the early universe. As such, these relic galaxies are essential in helping astronomers to understand how the first galaxies formed.
To assist in this line of inquiry, Comerón and colleagues observed the relic galaxy NGC 1277 with an instrument called an integral field spectrograph. This allowed them to map the motion of the galaxy and determine its mass and how that mass is distributed.
This revealed that the distribution of NGC 1277's total mass — which should include dark matter — was the same as the distribution of the mass of its everyday matter contents, in other words, stars, dust, gas and planets. That means that within the galaxy's radius, there can't be a dark matter content any greater than 5%, but the findings are more consistent with a complete absence of dark matter in NGC 1277.
This is surprising, as the currently favored models of cosmic evolution including the standard model of cosmology, suggest NGC 1277 should be comprised of between 10% and 70% dark matter.
"This discrepancy between the observations and what we would expect is a puzzle, and maybe even a challenge for the standard model," team member and University of La Laguna researcher Ignacio Trujillo said.
Where did relic galaxy's dark matter go?
The scientists behind this revelation have a few ideas about why NGC 1277 is so deficient in dark matter.
"One is that the gravitational interaction with the surrounding medium within the galaxy cluster in which this galaxy is situated has stripped out the dark matter," team member and University of La Laguna researcher Anna Ferré-Mateu. "The other is that the dark matter was driven out of the system when the galaxy formed by the merging of protogalactic fragments, which gave rise to the relic galaxy."
The team isn't totally satisfied with either explanation and will, therefore, continue investigating NGC 1277 with the William Herschel Telescope (WHT) at the Roque de los Muchachos Observatory on the Canary Island of La Palma.
If these future investigations confirm this relic galaxy lacks the universe's most mysterious form of matter, the scientists think this won't challenge the existence of dark matter altogether. Conversely, the team believes it would challenge alternatives to dark matter models, so-called modified gravity theories.
"Although the dark matter in a specific galaxy can be lost, a modified law of gravity must be universal; it cannot have exceptions," said Trujillo. "So a galaxy without dark matter is a refutation of this type of alternative to dark matter."
Conclusive answers will have to wait, though, Comerón acknowledged. "The puzzle of how a massive galaxy can form without dark matter remains a puzzle," the scientist concluded.
The team's research is published in the journal Astronomy and Astrophysics.
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Cosmology & The Universe
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WASHINGTON -- A stellar nursery where stars are born, interactions between galaxies and a unique view of an exoplanet are just some of the new cosmic images were shared Tuesday.After decades of waiting, it's finally time for the world to see the first images taken by the most powerful space telescope ever -- the James Webb Space Telescope.Development of the world's premier space observatory began in 2004, and after years of delays, the telescope and its massive gold mirror finally launched on December 25.The images are worth the wait -- and they will forever change the way we see the universe.President Joe Biden released one of Webb's first images on Monday, and it is "the deepest and sharpest infrared image of the distant universe to date," according to NASA. The rest of the high-resolution color images made their debut on Tuesday.MORE: President Biden reveals the Webb Telescope's stunning first imageThe space observatory can investigate the mysteries of the universe by observing them through infrared light, which is invisible to the human eye.Webb will peer into the very atmospheres of exoplanets, some of which are potentially habitable, and it could uncover clues in the ongoing search for life outside of Earth.The telescope will also look at every phase of cosmic history, including the first glows after the big bang that created our universe and the formation of the galaxies, stars and planets that fill it today.Now, Webb is ready to help us understand the origins of the universe and begin to answer key questions about our existence, such as where we came from and if we're alone in the cosmos.The first imagesThe first image, released on Monday, shows SMACS 0723, where a massive group of galaxy clusters act as a magnifying glass for the objects behind them. Called gravitational lensing, this created Webb's first deep field view that includes incredibly old and faint galaxies.Some of these distant galaxies and star clusters have never been seen before. The galaxy cluster is shown as it appeared 4.6 billion years ago.The image, taken by Webb's Near-Infrared Camera, is composed of images taken at different wavelengths of light over a collective 12.5 hours. Deep field observations are lengthy observations of regions of the sky that can reveal faint objects.Webb's other primary targets for the first image release included the Carina Nebula, WASP-96 b, the Southern Ring Nebula and Stephan's Quintet.Webb's study of the giant gas planet WASP-96 b is the most detailed spectrum of an exoplanet to date. The spectrum includes different wavelengths of light that reveal new information about the planet and its atmosphere. Discovered in 2014, WASP-96 b is located 1,150 light-years from Earth. It has half the mass of Jupiter and completes an orbit around its star every 3.4 days.Webb's spectrum includes "the distinct signature of water, along with evidence for clouds and haze, in the atmosphere surrounding a hot, puffy gas giant planet orbiting a distant Sun-like star," according to NASA.The observation demonstrates "Webb's unprecedented ability to analyze atmospheres hundreds of light-years away," according to NASA.In the future, Webb will capture actual images of known exoplanets while also searching for unknown planets, said Knicole Colón, Webb deputy project scientist for exoplanet science at NASA's Goddard Space Flight Center, during a news conference. And the spectrium of WASP-96 b is "barely scratching the surface of what we're going to learn."Colón anticipates that scientists will determine just how much water is in the exoplanet's atmosphere.The Southern Ring Nebula, also called the "Eight-Burst," is 2,000 light-years away from Earth. This large planetary nebula includes an expanding cloud of gas around a dying star. Webb helped reveal previously hidden details about the nebula, which is a shell of gas and dust released by the dying star. The nebula's second star can be seen in the Webb image, as well as how the stars shape the gas and dust cloud.The second star is surrounded by dust while the brighter star, at an earlier stage of evolution, will release its own cloud of gas and dust later on. As the two stars orbit one another, they effectively "stir" the gas and dust, resulting in the patterns seen in the image.The insights from images like this could help astronomers to unlock how stars change their environments as they evolve. Multi-colored points of light in the background represent galaxies.The space telescope's view of Stephan's Quintet shows the way galaxies interact with one another. This compact galaxy group, first discovered in 1787, is located 290 million light-years away in the constellation Pegasus. Four of the five galaxies in the group "are locked in a cosmic dance of repeated close encounters," according to a NASA statement.If you've ever watched "It's a Wonderful Life," you've seen Stephan's Quintet. Now, Webb has revealed the galactic grouping in a new mosaic which is the telescope's largest image to date."The information from Webb provides new insights into how galactic interactions may have driven galaxy evolution in the early universe," according to NASA.The Stephan's Quintet image provides a rare glimpse into how galaxies can trigger star formation in one another when they interact, as well as outflows driven by a black hole at a new level of detail.The gravitational dance between these galaxies can be seen through tails of gas, dust and stars and even shock waves as one of the galaxies pushes through the cluster.Located 7,600 light-years away, the Carina Nebula is a stellar nursery, where stars are born. It is one of the largest and brightest nebulae in the sky and home to many stars much more massive than our sun.Now, its "Cosmic Cliffs" are revealed in an incredible new Webb image.Webb's ability to see through cosmic dust has revealed previously invisible areas of star birth within the nebula, which could provide new insight on the formation of stars. The earliest stages of star formation are harder to capture -- but something Webb's sensitivity can chronicle.What looks like a landscape in the image is really a massive gaseous cavity with "peaks" reaching 7 light-years high."The cavernous area has been carved from the nebula by the intense ultraviolet radiation and stellar winds from extremely massive, hot, young stars located in the center of the bubble, above the area shown in this image," according to NASA. And what looks like "steam" rising off the "mountains" is hot, energetic gas and dust.The targets were selected by an international committee, including members from NASA, the European Space Agency, the Canadian Space Agency and the Space Telescope Science Institute in Baltimore.A long future of observationThe mission, originally expected to last for 10 years, has enough excess fuel capability to operate for 20 years, according to NASA Deputy Administrator Pam Melroy.These will be just the first of many images to come from Webb over the next two decades, which promises to fundamentally alter the way we understand the cosmos.While some of what Webb could reveal has been anticipated, the unknowns are just as exciting to scientists."We don't know what we don't know yet," said Amber Straughn, Webb deputy project scientist for communications at NASA Goddard. "I think it's true that every time we launch a revolutionary instrument into space, like with Hubble, we learn things that completely surprise us but do cause us to sort of change our fundamental understanding of how the universe works."Hubble's 31 years have yielded a wealth of discoveries that couldn't be anticipated, and the scientific community views Webb and its capabilities in the same way.When comparing Webb's first images to other breakthroughs in astronomy, Webb program scientist and NASA Astrophysics Division chief scientist Eric Smith compared it to seeing Hubble's images after the telescope was repaired and everything snapped into focus."A lot of people sometimes see pictures of space and they think it makes them feel small," Smith said. "When I see these pictures, they make me feel powerful. A team of people can make this unbelievable instrument to find out things about the universe revealed here, and just seeing that pride in the team, and pride in humanity, that when we want to, we can do that.""The universe has [always] been out there," said Jane Rigby, Webb operations project scientist at NASA Goddard. "We just had to build a telescope to go see what was there. Yeah, very similar feeling of, maybe, people in a broken world managing to do something right and to see some of the majesty that is out there."The-CNN-Wire ™ & © 2022 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.
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Cosmology & The Universe
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When it comes to exploration, robots can outperform astronauts at a far lower cost and without risk of human life. Why, then, do so many people conceive of space exploration as the domain of humans rather than robotic explorers? Martin Rees and Donald Goldsmith explore why robots are the future of space exploration.How much do we need humans in space? How much do we want them there? Astronauts embody the triumph of human imagination and engineering. Their efforts shed light on the possibilities and problems posed by travel beyond our nurturing Earth. Their presence on the moon or on other solar-system objects can imply that the countries or entities that sent them there possess ownership rights. Astronauts promote an understanding of the cosmos and inspire young people toward careers in science. SUGGESTED READING Billionaires in space By Tony Milligan When it comes to exploration, however, our robots can outperform astronauts at a far lower cost and without risk of human life. This assertion, once a prediction for the future, has become reality today, and robot explorers will continue to become ever more capable, while human bodies will not. Fifty years ago, when the first geologist to reach the moon suddenly recognized strange orange soil (the likely remnant of previously unsuspected volcanic activity) no one claimed that an automated explorer could have accomplished this feat. Today we have placed a semiautonomous rover on Mars, one of a continuing suite of orbiters and landers, with cameras and other instruments that probe the Martian soil, capable of finding paths around obstacles as no previous rover could. The first helicopter flight achieved in another body’s atmosphere marks the opening of new methods of exploration. NASA has plans to search for signs of ancient or even present-day life on Mars by bringing carefully selected samples of Martian soil back to Earth. Our robot explorers have visited all the sun’s planets (including that former planet Pluto), as well as two comets and an asteroid, securing immense amounts of data about them and their moons, most notably Jupiter’s Europa and Saturn’s Enceladus, where oceans that lie beneath an icy crust may harbor strange forms of life. Future missions from the United States, the European Space Agency, China, Japan, India, and Russia will only increase our robot emissaries’ abilities and the scientific importance of their discoveries. Each of these missions has cost far less than a single voyage that would send not robots but humans, which in any case remains an impossibility, for the next few decades, for any destination save the moon and Mars.Why, then, do so many people conceive of space exploration as the domain of human rather than robotic explorers? Here we may cite six chief factors, often interrelated:Tradition: From Marco Polo to Columbus, from Ernest Shackleton to Yuri Gagarin and Neil Armstrong, we conceive of exploration as requiring the direct engagement of humans.Engagement: We naturally relate to humans far more than to machines, though we may identify, to some degree, with the latter, from the Little Engine that Could to the rovers on Mars to the James Webb Space Telescope.Adventure: The difficulties and dangers of exploration bring a dramatic tension that has always appealed to us. If Columbus had merely sailed the Atlantic to visit friendly nations in the Americas, his voyages would hardly have captured as much attention from European powers.Inspiration: Children now easily imagine going into space, and from these dreams, great interest in science may arise. Along with adults, they receive continual stimulation from movies and television programs that feature humans who travel through space almost instantaneously (while in real life, a journey to Mars requires six months) and meet extraterrestrial beings who almost always have humanoid characteristics (not least because actors in costumes cost less than computer-generated aliens).Ownership: Just as Spain and Portugal vied to control the New World until the Pope drew a line of demarcation, modern nations seem ready to assert claims to portions of the moon, most notably over the “Peaks of Eternal Light,” mountains near the lunar south pole where the sun’s rays shine forever. This competition includes the creation of large-scale lunar colonies as arguments for ownership, or to mine the moon for material to create enormous numbers of free-orbiting space colonies, an important part of Jeff Bezos’s future plans (the moon’s low gravity strongly favors our satellite over our planet for such purposes).Wealth: Despite the immense distances to be traversed, entrepreneurs dream of obtaining rare and useful deposits, from a rare isotope of helium (for nuclear fusion) to the rare-Earth elements, available from only a few terrestrial locations (primarily in China), that have become essential for products ranging from cell phone to electric cars to fighter aircraft. Intriguingly, except for helium-3 buried in lunar soil, certain metal-rich asteroids with orbits that bring them comparatively close to Earth offer the most promising objects for such mining.___The best argument against long-term plans to “terraform” Mars by creating a more Earthlike environment remains the sad results of our “terraforming” of Earth___The first four of these six motivating factors spring from deeply embedded attitudes, relatively insusceptible to logic. Number three, Adventure, could be satisfied to a large degree by private space missions, all the more appropriate so long as the rate of catastrophe per launch stays above one percent. The last two, however, spring directly from the long history of conquest and exploitation of Earth’s resources, whose long and effective history has profoundly altered our planet. (The best argument against long-term plans to “terraform” Mars by creating a more Earthlike environment remains the sad results of our “terraforming” of Earth.) Whether or not one approves of them, both ownership claims and mineral extraction can be successfully prosecuted with machines. This also applies to scientific activities. For example, astronomers would dearly love to have a giant radio telescope on the far side of the moon, which would screen out terrestrial radio interference marvelously well. In the near future robots could build this telescope more efficiently and much more cheaply than humans.This discussion has barely touched on astronauts in low-Earth orbit, their only sphere of activity since Apollo 17 left the moon in 1972. In this realm, astronauts’ greatest achievement by far came with their five repair missions to the Hubble Space Telescope, which saved the giant instrument from uselessness and extended its life by decades by providing upgraded cameras and other systems. Each of these missions cost about a billion dollars in today’s money (Hubble’s total operational cost comes to $16 billion). The cost of a replacement telescope to replace the Hubble would likewise have been about a billion dollars; in fact, the director of the Space Telescope Science Institute said that the cost of the five repair missions would have paid for seven replacement telescopes. Astronauts could reach the Hubble only because the Space Shuttle, which launched it, could go no farther from Earth, which produces all sorts of interfering radiation and light. Today, astrophysicists have managed to send all of their new spaceborne observatories to distances to a region of space four times farther than the moon, where the James Webb Space Telescope now prepares to study a host of cosmic objects. Since 1988, multinational cooperation on the International Space Station, 250 miles above the Earth’s surface, has proven successful in achieving almost all of the tasks that NASA and its collaborators have set for the rotating teams of astronauts from 16 different countries. A closer look at these tasks, however, demonstrates the weakness of justifications for humans in even the most readily available realms of space. SUGGESTED READING The Philosophical Problems of Cosmology By George Ellis In 2020, NASA revealed its list of “20 Breakthroughs from 20 Years of Science aboard the International Space Station.” Seventeen of these dealt with processes that robots can perform, such as launching small satellites, the detection of cosmic particles, employing microgravity conditions for drug development and the study of flames, and spaceborne 3-D printing. The remaining three dealt with muscle atrophy and bone loss, growing food, or identifying microbes in space—important for humans in that environment, though hardly a rationale for sending them into space. How deeply will the arguments made here affect anyone who reads them? Opinions that have formed without considerations of logic are unlikely to be changed by appeals that rely on rational argument. Large numbers of us identify with the emotions that led Donald Trump to promise to put the first woman on the moon and to assure that the first person on Mars would be American. Others without such nationalistic impulses will insist that a key aspect of our destiny resides in sending humans into space. We have no good answer to these emotions. Nor can we successfully predict what may happen beyond a time horizon—let us say two decades—about which we can make reasonable forecasts. We can only urge our readers to think things over, to distinguish between scientific exploration and the other motivations for going into space, and to form—what else? —their own conclusions.Martin Rees' book The End of Astronauts is published by Harvard University Press.
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Cosmology & The Universe
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The Nancy Grace Roman Space Telescope is NASA's future infrared space observatory that will attempt to tackle some of the most pressing questions in cosmology by addressing the mysteries of dark energy.
The telescope also known as "Roman" or the "Roman Space Telescope" will also search for planets outside the solar system — exoplanets, and will investigate the physics of distant stars.
Set to launch around 2026 or 2027, NASA says (opens in new tab) that the space telescope possesses a wide field of view that will allow it to generate never-before-seen big pictures of the universe essential for tackling some of the most pressing cosmic mysteries. The mission is projected to last for five years.
The Roman space telescope will be situated at Lagrange point 2, a stable gravitational point between Earth and the sun located around 1 million miles (1.5 million kilometers) from our planet.
Who is telescope named after?
The Nancy Grace Roman Space Telescope began life as the Wide Field Infrared Survey Telescope (WFIRST) in 2010, only gaining its current name a decade later when in May 2020 it was renamed in honor of Nancy Grace Roman, a pioneering scientist who served as NASA's first chief astronomer from 1961 to 1963. Roman passed away on December 26, 2018, at the age of 93.
During her life, Roman was affectionately known as "the mother of Hubble" the nickname emerged due to the fact that Roman tirelessly advocated for new tools that would allow scientists to study the broader universe which led to the launch of the Hubble Space Telescope in 1990.(opens in new tab)
Announcing the new moniker for WFIRST in 2020 then NASA administrator, Jim Bridenstine said: (opens in new tab) "It is because of Nancy Grace Roman's leadership and vision that NASA became a pioneer in astrophysics and launched Hubble, the world's most powerful and productive space telescope."
"I can think of no better name for WFIRST, which will be the successor to NASA's Hubble and Webb Telescopes." Bridenstine continued.
"Roman is planned to teach us a great deal about exoplanets and cosmology, but will have the capability to do so much more," Postdoctoral Fellow at NASA's Jet Propulsion Laboratory, Samson A. Johnson told Space.com. "Right now, and all the way up to and after its launch, there will be a lot of opportunities for astronomers to propose their own ideas for Roman, and there are many interesting prospects such as studying stellar mass black holes, exoplanet transit surveys, asteroseismology surveys, and much, much more." Johnson continued.
Nancy Grace Roman Space Telescope development and cost(opens in new tab)
The development of the Nancy Grace Roman Space Telescope has been handled primarily by NASA's Goddard Space Flight Center, with participation by the Jet Propulsion Laboratory (JPL) and the Infrared Processing and Analysis Center, in Pasadena, California, the Space Telescope Science Institute in Baltimore, and a science team comprised researchers from institutions across the U.S.
The development of the Nancy Grace Roman Space Telescope has been handled primarily by NASA's Goddard Space Flight Center, with participation by the Jet Propulsion Laboratory (JPL) and the Infrared Processing and Analysis Center, in Pasadena, California, the Space Telescope Science Institute in Baltimore, and a science team comprised researchers from institutions across the U.S.
Initial designs for the Roman Space Telescope from 2011 suggested it would be equipped with a smaller 4.3 ft (1.3 m) diameter mirror and a single instrument. The current and final design of the telescope was introduced in 2015 in the WFIRST-AFTA 2015 Report by the Science Definition Team (SDT) and WFIRST Study Office.
The title of the paper detailing an updated Roman telescope that will reach space later this decade was released in 2019, tellingly entitled 'The Wide Field Infrared Survey Telescope: 100 Hubbles for the 2020s (opens in new tab)."
In 2022, NASA estimated the total launch cost of the Roman telescope as $255 million, which includes the launch service and other mission-related costs.
What will the Nancy Grace Roman Space Telescope do?
According to the WFIRST-AFTA Science Definition Team Final Report (opens in new tab) the Roman Space Telescope will weigh 4,166 kilograms (9,184 pounds) at launch and is set to carry a payload of 2,191 kg (4,830 lb).
The primary mirror of the Roman Space Telescope has a diameter of 7.9 ft (2.4 meters), the same size as the mirror of Hubble but under a quarter of the weight at 410 pounds (186 kilograms).(opens in new tab)
The mirror grants the telescope a 0.281-degree square field of view and sends light to the two main instruments carried by the Roman Space Telescope, the Wide Field Instrument, and the telescope's Coronagraph Instrument. The barrel-like shape of the spacecraft itself blocks out unwanted light from the sun.
This will allow the Wide Field Instrument to measure the light from a billion galaxies over its 5 5-year-long operation time, thus facilitating the primary mission of the Roman Space Telescope — to investigate dark energy.
As NASA points out, (opens in new tab) physicists estimate that dark energy accounts for around 68% of the universe's total energy/matter content, yet have little idea what it actually is. One way of addressing this problem could be to observe how the influence of dark energy has changed over time.
The Wide Field Instrument on the Roman Space Telescope will help investigate this by mapping the distribution of matter across the universe and measuring how the universe has expanded since it was around 500 million years old, about 4% of its current age. Examining the brightness and distances of supernovas, the explosions that occur at the end of stars' lives, the Roman Space Telescope may detect the first traces of dark energy thus giving scientists an idea of how the influence of this mysterious force has grown over time.
Among the other objectives of Roman, such as the study of distant supernovas and the examination of objects on the outskirts of the solar system, will be the hunt for planets around other stars.
Nancy Grace Roman Telescope and dark energy FAQs answered by an expert
Luz Ángela García is a cosmology postdoctoral researcher at Universidad ECCI in Bogotá, Colombia.
We asked Luz Ángela García, a cosmology postdoc in Bogotá, Colombia, a few questions about the Nancy Grace Roman Telescope and dark energy.
How does the Nancy Grace Roman Space Telescope compare to the James Webb Space Telescope?
Both telescopes are optimized to work on the wavelength range of the infrared. However, the JWST has a very narrow and detailed field of view. Instead, the Nancy Grace Roman will cover a very broad patch of the sky. One way to understand this is that the science goals of both telescopes are different, and thus, their coverage has to adapt to these observational needs.
The JWST aims to recover deep lines of view of the sky. On the other hand, the Roman will provide us with the "Big Picture". It will complement other wide galaxy surveys run from the ground, such as DESI or the upcoming Vera Rubin Observatory.
How will the Nancy Grace Roman Space Telescope study dark energy?
Most capabilities of the Nancy Grace Roman will make it a suitable instrument to study the nature of dark energy. Because of its broad coverage of the sky, the telescope will capture an unprecedented number of galaxies in its field of view and the distribution of those galaxies in our universe, which will allow us to understand the effect of dark energy on large cosmological scales and the clustering and evolution of galaxies. With such an extensive map of the galaxies, we can recover a robust prediction of the acoustic peak.
On the other hand, the Nancy Grace Roman will focus on detecting signals in the infrared; thus, it will 'see' galaxies that the current ground-based telescopes could be missing. In addition, the telescope will observe a large number of supernova Ia (the same type of objects that led to the concept of dark energy and the accelerated expansion of the universe in the first place). Most importantly, its findings concerning dark energy and the Universe's large-scale structure will complement those made by other observatories.
What impact will the Nancy Grace Roman Space Telescope have on astronomy?
Every new telescope provides a new piece of information about dark energy, the structure of matter, and the universe itself. This telescope will allow us to get a very broad map of the galaxies in infrared, therefore, they will not be only nearby galaxies, but mostly early galaxies whose light has traveled for a long time before reaching the mirrors of the Roman, thus their light will exhibit large redshifts.
But the Nancy Grace Roman will also address other interesting topics in the discipline, such as exoplanets delivering the largest census of planetary systems in our galaxy and other astronomical challenges in the infrared that neither the HST nor the JWST can tackle because of their narrow view.
Hunting for exoplanets
"Roman is going to teach us about exoplanets in two ways. First, one of its Core Community Surveys is designed to detect microlensing events. These events are the extremely rare, near-perfect alignment of a foreground object and a background star, which is why we need Roman's large field-of-view to monitor for these rare events," Johnson explains. "The mass of the foreground object bends space in such a way that it magnifies the light coming from the background star, temporarily increasing its brightness. If there are any planets orbiting the lensing star, they will cause deviations in the magnification which will indicate their presence."
By using the tiny bending of light caused by the presence of mass the Wide Field Instrument will conduct a survey of the Milky Way and hunt for around 2,600 new exoplanets, according to NASA JPL (opens in new tab).
As this instrument searches for new exoplanets, the Roman Coronagraph will investigate dozens of already discovered exoplanets, by imaging them and carrying out spectroscopic — absorption and emissions of light and other radiation — observations.
Examining light as it passes through the atmospheres of exoplanets can reveal the elements that make up said atmospheres and can help scientists detect the presence of molecules such as water and complex organic molecules that could be the by-products of life.
Technology currently allows astronomers to detect bright young exoplanets that are around a million times dimmer than their host stars, but many exoplanets are fainter by their stars by factors of 100 million or more. This is especially true for "mature" gas giants like the solar system's own Jupiter and Saturn or rocky terrestrial worlds like Earth.
"The second way that Roman will study planets is by using its Coronographic Instrument, which is a technological demonstration of the first space-based adaptive optics," Johnson adds. "This will be critical for the future of directly imaging planets from space, and pave the way for the next generation of space telescopes searching for biosignatures in the 2040s."
The Roman Space Telescope Coronagraph Instrument will be the first high-performance coronagraph system sent into space with current lab tests indicating the instrument should be able to detect exoplanets a billion times fainter than their host star.
That makes Roman an important stepping stone for future missions that aim to image and characterize terrestrial planets 10 billion times fainter than their host star.
Space telescope showdown: Nancy Grace Roman vs the James Webb vs Hubble
Though it's natural to compare the abilities of, the Hubble space telescope, the James Webb Space Telescope, and the forthcoming Nancy Grace Roman Space Telescope, none of these instruments is strictly a replacement for its predecessor, instead, each telescope is intended to complement the other. Though all three instruments view the universe in infrared, they offer different cosmic perspectives.
|Header Cell - Column 0||Roman||Hubble||JWST|
|Wavelength coverage||0.5 to 2.3 microns (visible and infrared)||0.2 to 1.7 microns (ultraviolet light to near-infrared)||0.6 to 28 microns (near infrared, mid-infrared and small amount of visible light).|
|Primary mirror diameter||7.9 feet (2.4 meters)||7.9 feet (2.4 meters)||21 foot-diameter (6.5-meter)|
Roman's wavelength coverage of visible and infrared light will span 0.5 to 2.3 microns, which is a 20% increase over the mission's original design. NASA says (opens in new tab) this range will enable the telescope to better collaborate with the Hubble Space Telescope, which views the universe in ultraviolet light to near-infrared light, 0.2 to 1.7 microns, and the JWST which observes the cosmos in near-infrared, mid-infrared and a small amount of visible light, from 0.6 to 28 microns.
The silver-coated mirror of Roman is the same size as Hubble's primary mirror, but it is dwarfed by the gold-coated mirror 21 foot-diameter (6.5-meter) mirror of the JWST. This huge mirror made of 18 hexagonal segments makes the JWST 100 times more powerful than Hubble and can see objects 100 times fainter than Hubble allowing it to see deeper into the universe. Because light has a finite traveling speed this means the JWST can see further back in time than Hubble, too.(opens in new tab)
"The best way to compare Roman and Webb is actually to compare them to Hubble. Webb's big advantage over Hubble is that it is much more sensitive and can detect sources of light 100 times fainter than Hubble," Johnson said. "This makes Webb an excellent 'Swiss army knife' type observatory, very flexible and can observe a wide range of objects from the first galaxies to directly imaging exoplanets.
"Roman has a similar sensitivity to Hubble, but it has a much wider field of view. In one pointing, Roman can observe a patch of sky 100 times larger than Hubble can in a single pointing. This makes Roman great at observing thousands of galaxies at a time or tens of millions of stars in one image."
NASA estimates that Roman's infrared vision should also allow the telescope to see back into the universe to when it was little more than 300 million years old. Though Roman's main strength, according to NASA (opens in new tab), is the size of its field of view.
Roman's Wide Field Instrument's field of view is 100 times greater than Hubble's widest exposure. Roman will therefore generate much larger views of the cosmos while matching Hubble's crisp infrared resolution. In its first five years of operation, Roman will image over 50 times as much of the night sky as Hubble has done since 1990. Though Hubble can still capture something Roman can't provide, high-resolution ultraviolet observations, thus demonstrating that even the oldest of these three 'mega-telescopes' is in no way made obsolete by its predecessors.
This will allow Roman to spot targets in its wide-field view for Hubble to follow up in infrared, and for the JWST to get a clearer and deeper view of.
"Combining the Roman Space Telescope's findings with Hubble's and Webb's could revolutionize our understanding in a multitude of cosmic pursuits," NASA says. (opens in new tab)
Additional resources
The inspiration behind the Nancy Grace Roman Space Telescope and so many of NASA's pioneering missions is its first chief astronomer, Nancy Grace Roman. You can read about her life in her own words in an interview conducted before her death in 2018, during a series of interviews she gave with NASA (opens in new tab).
The primary mission of the Nancy Grace Roman Space Telescope will be the investigation of dark energy. You can get the lowdown on this mysterious force driving the expansion of the universe, with these resources from NASA (opens in new tab). Put your observation skills to the test with NASA's Roman Space Observer game.
Bibliography
The Nancy Grace Roman Space Telescope, NASA Goddard Space Flight Center, [Accessed 01/26/23], [https://roman.gsfc.nasa.gov/ (opens in new tab)]
The Nancy Grace Roman Space Telescope, NASA JPL, [Accessed 01/26/23], [https://www.jpl.nasa.gov/missions/the-nancy-grace-roman-space-telescope (opens in new tab)]
NASA Awards Launch Services Contract for Roman Space Telescope, NASA TV, [Accessed 01/26/23], [https://www.nasa.gov/press-release/nasa-awards-launch-services-contract-for-roman-space-telescope (opens in new tab)]
Roman Space Telescope Mission Overview, NASA, [Accessed 01/26/23], [https://roman.gsfc.nasa.gov/about.html (opens in new tab)]
Assembly Begins on NASA's Next Tool to Study Exoplanets, NASA TV, [2022], [https://www.nasa.gov/feature/jpl/assembly-begins-on-nasa-s-next-tool-to-study-exoplanets (opens in new tab)]
Nancy Roman (1925-2018), Astronomer / "Mother of Hubble" NASA, [Accessed 01/26/23], [https://solarsystem.nasa.gov/people/225/nancy-roman-1925-2018/ (opens in new tab)]
Why Roman Space Telescope, NASA Goddard Space Flight Cente, [Accessed 01/26/23], [https://roman.gsfc.nasa.gov/why_Roman_Space_Telescope.html (opens in new tab)]
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Cosmology & The Universe
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A chameleon-like force that shifts its nature based on its environment could explain a major physics quandary: how the mysterious substance called dark energy is compelling the cosmos to expand faster and faster. But a new experiment casts doubt on some chameleon theories, researchers report August 25 in Nature Physics. The chameleon force would be a fifth type of force beyond the basic four: gravitational, strong, weak and electromagnetic. And like a chameleon changing its colors, the hypothetical fifth force would morph depending on the density of its surroundings. In dense environments like Earth, this fifth force would be feeble, camouflaging its effects. In the sparseness of space, the force would be stronger and long-ranged. Sign Up For the Latest from Science News Headlines and summaries of the latest Science News articles, delivered to your inbox This force would result from a chameleon field — an addition to the known fields in physics, such as electric, magnetic and gravitational fields. A chameleon field with these morphing properties could drive the accelerating expansion of the universe without disagreeing with measurements on Earth. But it’s a challenge to suss out such a changeling force. On Earth, says astrophysicist Jianhua He of Nanjing University in China, “it’s very, very tiny. That’s the most difficult part.” So He and colleagues designed a detector to search for a subtle fifth force. A wheel with plastic films attached spins past another film sitting on a magnetically levitated piece of graphite. If a chameleon force really exists, the films spinning by would cause a periodic force on the levitating plastic, pulling it up and down. (Gravity also acts this way, but thanks to the device’s design, it should be much weaker than a chameleon force.) The team was able to rule out a category of chameleon theories. In the future, the researchers hope to improve their results by chilling their device to allow for more sensitive measurements.
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Cosmology & The Universe
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Scientists have mapped out the dark matter around some of the earliest, most distant galaxies yet. The 1.5 million galaxies appear as they were 12 billion years ago, or less than 2 billion years after the Big Bang. Those galaxies distort the cosmic microwave background — light emitted during an even earlier era of the universe — as seen from Earth. That distortion, called gravitational lensing, reveals the distribution of dark matter around those galaxies, scientists report in the Aug. 5 Physical Review Letters. Sign Up For the Latest from Science News Headlines and summaries of the latest Science News articles, delivered to your inbox Understanding how dark matter collects around galaxies early in the universe’s history could tell scientists more about the mysterious substance. And in the future, this lensing technique could also help scientists unravel a mystery about how matter clumps together in the universe. Dark matter is an unknown, massive substance that surrounds galaxies. Scientists have never directly detected dark matter, but they can observe its gravitational effects on the cosmos (SN: 7/22/22). One of those effects is gravitational lensing: When light passes by a galaxy, its mass bends the light like a lens. How much the light bends reveals the mass of the galaxy, including its dark matter. It’s difficult to map dark matter around such distant galaxies, says cosmologist Hironao Miyatake of Nagoya University in Japan. That’s because scientists need a source of light that is farther away than the galaxy acting as the lens. Typically, scientists use even more distant galaxies as the source of that light. But when peering this deep into space, those galaxies are difficult to come by. So instead, Miyatake and colleagues turned to the cosmic microwave background, the oldest light in the universe. The team used measurements of lensing of the cosmic microwave background from the Planck satellite, combined with a multitude of distant galaxies observed by the Subaru Telescope in Hawaii (SN: 7/24/18). “The gravitational lensing effect is very small, so we need a lot of lens galaxies,” Miyatake says. The distribution of dark matter around the galaxies matched expectations, the researchers report. The researchers also estimated a quantity called sigma-8, a measure of how “clumpy” matter is in the cosmos. For years, scientists have found hints that different measurements of sigma-8 disagree with one another (SN: 8/10/20). That could be a hint that something is wrong with scientists’ theories of the universe. But the evidence isn’t conclusive. “One of the most interesting things in cosmology right now is whether that tension is real or not,” says cosmologist Risa Wechsler of Stanford University, who was not involved with the study. “This is a really nice example of one of the techniques that will help shed light on that.” Measuring sigma-8 using early, distant galaxies could help reveal what’s going on. “You want to measure this quantity, this sigma-8, from as many perspectives as possible,” says cosmologist Hendrik Hildebrandt of Ruhr University Bochum in Germany, who was not involved with the study. If estimates from different eras of the universe disagree with one another, that might help physicists craft a new theory that could better explain the cosmos. While the new measurement of sigma-8 isn’t precise enough to settle the debate, future projects, such as the Rubin Observatory in Chile, could improve the estimate (SN: 1/10/20).
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Cosmology & The Universe
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Everything we know about the evolution of the early universe is currently being challenged. Multiple galaxies discovered by the James Webb Space Telescope do not match up with the standard model of cosmology that astronomers currently believe in.
According to a new study published in Nature Astronomy, six of the earliest galaxies that Webb has observed contradict how astronomers currently look at the evolution of the early universe. The author of the study, Mike Boylan-Kolchin, says that these galaxies are too big to fit our current models.
When we look at the evolution of the early universe, we often expect to see much smaller galaxies. However, out of the six that Boylan-Kolchin focuses on, all of them are much more massive than scientists previously believed possible within that time. Astronomers estimate each of the galaxies to be from 500 to 700 million years ago.
However, each of them measures over 10 billion times as massive as our Sun. In fact, one of them even appears to be much more massive than the Milky Way, although our galaxy has had billions of more years to evolve and shed its ancient core. These discoveries, Boylan-Kolchin says, could completely change how we address the evolution of the early universe.
Boylan-Kolchin says that we’re in “uncharted territory” if the masses scientists estimate turn out to be correct. This discovery could require that we look at unknown forces and particles to try to understand how the universe expanded so quickly to include such heavily evolved galaxies. It’s also possible that we aren’t looking back as far as we thought. We need more research to draw a final conclusion.
Of course, we always knew that James Webb was going to challenge things we thought we understood. The telescope is peering deeper into space and further back in time than we’ve ever been able to before. It’s likely this is just one of many things that will challenge our current understanding of the evolution of the early universe.
But every challenge that comes forward allows us to look closer at what we know and don’t know. It allows us to clean up lines that have remained blurred for decades. Lines that we need to more clearly trace if we want to truly understand it all.
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Cosmology & The Universe
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By Daniel StolteA new technique for estimating the mass of the Milky Way galaxy promises more reliable results, especially when it’s applied to large datasets generated by current and future surveys, according to new research. The study, which appears in the Astrophysical Journal, is the first to combine the observed full three-dimensional motions of several of the Milky Way’s satellite galaxies with extensive computer simulations to obtain a high-accuracy estimate for the mass of our home galaxy.Determining the mass of galaxies plays a crucial part in unraveling fundamental mysteries about the architecture of the universe.According to current cosmological models, a galaxy’s visible matter, such as stars, gas, and dust, accounts for a mere 15 percent of its mass. The remaining 85 percent is believed to reside in dark matter, a mysterious component that never has been observed and whose physical properties remain largely unknown. Weighing the Milky WayThe vast majority of a galaxy’s mass (mostly dark matter) is located in its halo, a vast, surrounding region containing few, if any, stars and whose shape is largely unknown.In a widely accepted cosmological model, dark-matter filaments span the entire universe, drawing luminous (“regular”) matter with them. Where they intersect, gas and dust accumulate and coalesce into galaxies.Over billions of years, small galaxies merge to form into larger ones, and as those grow in size and their gravitational pull reaches farther and farther into space, they attract a zoo of other small galaxies, which then become satellite galaxies. Their host galaxy determines their orbits, much like the sun’s gravitational pull directs the movement of planets and bodies in the solar system.“We now know that the universe is expanding,” says Ekta Patel, a fourth-year graduate student in the astronomy department and Steward Observatory at the University of Arizona. “But when two galaxies come close enough, their mutual attraction is greater than the influence of the expanding universe, so they begin to orbit each other around a common center, like our Milky Way and our closest neighbor, the Andromeda Galaxy.”Although Andromeda is approaching the Milky Way at 110 kilometers per second, the two won’t merge until about 4.5 billion years from now. According to Patel, tracking Andromeda’s motion is “equivalent to watching a human hair grow at the distance of the moon.”Because it’s impossible to “weigh” a galaxy simply by looking at it—much less when the observer happens to be inside of it, as is the case with our Milky Way—researchers deduce a galaxy’s mass by studying the motions of celestial objects as they dance around the host galaxy, led by its gravitational pull.Such objects—also called tracers, because they trace the mass of their host galaxy—can be satellite galaxies or streams of stars created from the scattering of former galaxies that came too close to remain intact.Unlike previous methods commonly used to estimate a galaxy’s mass, such as measuring its tracers’ velocities and positions, the approach Patel and her coauthors developed uses their angular momentum, which yields more reliable results because it doesn’t change over time.The angular momentum of a body in space depends on both its distance and speed. Since satellite galaxies tend to move around the Milky Way in elliptical orbits, their speeds increase as they get closer to our galaxy and decrease as they get farther away. Because the angular momentum is the product of both position and speed, there is no net change regardless of whether the tracer is at its closest or farthest position in its orbit. “Think of a figure skater doing a pirouette,” Patel says. “As she draws in her arms, she spins faster. In other words, her velocity changes, but her angular momentum stays the same over the whole duration of her act.”The study, which Patel presented on Thursday, June 7, at the 232nd meeting of the of the American Astronomical Society in Denver, is the first to look at the full three-dimensional motions of nine of the Milky Way’s 50 known satellite galaxies at once and compare their angular momentum measurements to a simulated universe containing a total of 20,000 host galaxies that resemble our own galaxy. Together those simulated galaxies host about 90,000 satellite galaxies. So, what’s the Milky Way’s mass?Patel’s team pinned down the Milky Way’s mass at 0.96 trillion solar masses. Previous estimates had placed our galaxy’s mass between 700 billion and 2 trillion solar masses. The results also reinforce estimates suggesting that the Andromeda Galaxy (M31) is more massive than our Milky Way.The authors hope to apply their method to the ever-growing data as they become available by current and future galactic surveys such as the Gaia space observatory and LSST, the Large Synoptic Survey Telescope. According to coauthor Gurtina Besla, an assistant professor of astronomy at the University of Arizona, constraints on the mass of the Milky Way will improve as researchers obtain new observations that clock the speed of more satellite galaxies, and as next-generation simulations will provide higher resolution, allowing scientists to get better statistics for the smallest mass tracers, the so-called ultra-faint galaxies.“Our method allows us to take advantage of measurements of the speed of multiple satellite galaxies simultaneously to get an answer for what cold dark matter theory would predict for the mass of the Milky Way’s halo in a robust way,” Besla says. “It is perfectly suited to take advantage of the current rapid growth in both observational datasets and numerical capabilities.”Additional coauthors of the paper are from the Institute of Astronomy and the University of Cambridge, UK, and the Space Telescope Science Institute in Baltimore. The National Science Foundation and NASA provided funding the project.Source: University of Arizona via Futurity - Original Study DOI: 10.3847/1538-4357/aab78f If you enjoy our selection of content please consider following Universal-Sci on social media:
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Cosmology & The Universe
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Infinity is back. Or rather, it never (ever, ever…) went away. While mathematicians have a good sense of the infinite as a concept, cosmologists and physicists are finding it much more difficult to make sense of the infinite in nature, writes Peter Cameron. Each of us has to face a moment, often fairly early in our life, when we realize that a loved one, formerly a fixture in our life, was not infinite, but has left us, and that someday we too will have to leave this place. This experience, probably as much as the experience of looking at the stars and wondering how far they go on, shapes our views of infinity. And we urgently want answers to our questions. This has been so since the time, two and a half millennia ago, when Malunkyaputta put his doubts to the Buddha and demanded answers: among them he wanted to know if the world is finite or infinite, and if it is eternal or not. Recently we have heard again John Donne's words promising us that eternity consists of "no noise nor silence, but one equal music;no ends or beginnings, but one equal eternity."Hard to imagine, and surely one equal music would soon become intolerable!There are many approaches to infinity through the twin pillars of science and religion, but I will just restrict my attention here to the views of mathematicians and physicists.Aristotle was one of the most influential Greek philosophers. He believed that we could consider "potential infinity" (we can count objects without knowing how many more are coming) but that a "completed infinity" is taboo. For mathematicians, infinity was off-limits for two millennia after Aristotle's ban. Galileo tried to tackle the problem, noting that an infinite set could be matched up with a part of itself, but in the end drew back. It was left to Cantor in the nineteenth century to show us the way to think about infinity, which is accepted by most mathematicians now. There are infinitely many counting numbers; any number you write down is a negligible step along the way to infinity. So Cantor's idea was to imagine we have a package containing all these numbers; put a label on it saying "The natural numbers", and treat the package as a single entity. If you want to study individual numbers, you can break open the package and take them out to look at them. Now you can take any collection of these packages, and bundle them up to form another single entity. Thus, set theory is born. Cantor investigated ways of measuring these sets, and today set theory is the commonest foundation for mathematics, though other foundations have been proposed. ___If you toss a coin 100 times, it is not impossible (just very unlikely) that it will come down tails each time. But, if you could imagine tossing a coin infinitely often, then the chance of not getting heads and tails equally often is zero___One of Cantor's discoveries is that there is no largest infinite set: given any set you can always find a larger one. The smallest infinite set is the set of natural numbers. What comes next is a puzzle which can't be resolved at present. It may be the real (decimal) numbers, or maybe not. Our current foundations are not strong enough, and building larger telescopes will not help with this question. Perhaps in the future we will adopt new foundations for mathematics which will resolve the question. But for now, since mathematics is a mental construction, we can decide whether the universe we are playing in satisfies the "continuum hypothesis" or not. These questions keep set theorists awake at night; but most mathematicians work near the bottom of this dizzying hierarchy, with small infinities. For example, Euclid proved that the prime numbers "go on for ever". (Aristotle would say, "Whatever prime you find, I can find a larger one"; Cantor would simply say "The set of prime numbers is infinite." Mathematicians (including this year's Fields Medallist James Maynard from Oxford) seem to be closing in on the Twin Primes Conjecture. Twin primes are pairs of prime numbers, such as 3 and 5, or 71 and 73, differing by just 2; the conjecture, unproved as yet, asserts that there are infinitely many of them. But these are the infinities of the natural numbers, the smallest infinity. SUGGESTED READING Physics alone can't answer the big questions By SabineHossenfelder While Kronecker (a fierce opponent of Cantor's ideas) thought in the nineteenth century that "God created the natural numbers; the rest is the work of man", we can now build the natural numbers using the tools of set theory, starting from nothing (more precisely the empty set).Mathematicians know, however, that there is a huge gap between the finite and the infinite. If you toss a coin 100 times, it is not impossible (just very unlikely) that it will come down tails each time. But, if you could imagine tossing a coin infinitely often, then the chance of not getting heads and tails equally often is zero. Of course, you could never actually perform this experiment; but mathematics is a conceptual science, and we are happy to accept this statement on the basis of a rigorous proof.Infinity in physics and cosmology has not been resolved so satisfactorily. The two great twentieth-century theories of physics, general relativity (the theory of the very large) and quantum mechanics (the theory of the very small) have resisted attempts to unite them. The one thing most physicists can agree on is that the universe came into being a finite time ago (about 13.7 billion years) -- large, but not infinite. ___They deny that the infinitely small can exist in the universe, but prescribe a minimum possible scale, essentially the so-called Planck scale___The James Webb Space Telescope has just begun showing us unprecedented details in the universe. As well as nearby objects, it sees the furthest objects ever observed. Because light travels at a finite speed, these are also the oldest objects observed, having been formed close to the beginning of the Universe. The finite speed of light also puts limits on what we can see; if an object is so far away that its light could not reach us if it travelled for the whole age of the universe, then we are unaware of its existence. So Malunkyaputta's question about whether the universe is finite or infinite is moot. But is it eternal or not? That is a real question, and is so far undecided.Attempts to reconcile relativity and quantum theory have been made. The ones currently most promising adopt a very radical attitude to infinity. They deny that the infinitely small can exist in the universe, but prescribe a minimum possible scale, essentially the so-called Planck scale. SUGGESTED VIEWING The Infinite Puzzle With David Malone, Laura Mersini-Houghton, Peter Cameron, Julian Barbour Such a solution would put an end to Zeno's paradox. Zeno denied the possibility of motion, since to move from A to B you first have to move to a point C halfway to B, and before that to a point D halfway from A to C, and so on to infinity. If space is not infinitely divisible, then this infinite regress cannot occur. (This solution was already grasped by Democritus and the early Greek atomists.)Of course, this leaves us with a conceptual problem similar to the one raised by the possibility that the university is finite. In that case, the obvious question is "If the universe has an edge, what is beyond it?" In the case of the Planck length, the question would be "Given any length, however small, why can't I just take half of it?"Perhaps because we have been conditioned by Zeno's paradox, we tend to think of the points on a line to be, like the real numbers, infinitely divisible: between any two we can find another. But current thinking is that the universe is not built this way.___Time, however, remains a problem___More important to physics, the atomist hypothesis also gets rid of another annoying occurrence of infinity in physics. Black holes in general relativity are points of spacetime where the density of matter becomes infinite and the laws of physics break down. These have been a thorn in the flesh of cosmologists since their existence was first predicted, since by definition we cannot understand what happens there. If space is discrete, we cannot put infinitely many things infinitely close together, and the paradox is avoided. We can still have extremely high density; the black hole recently observed and photographed at the centre of our own galaxy is (on this theory) just a point of such high density that light cannot escape, but does not defy our ability to understand it.Time, however, remains a problem; current theories cannot decide the ultimate fate of the universe. Does it end with heat death, a cold dark universe where nothing happens? Does the mysterious "dark energy" become so strong that it rips the universe to shreds? Or does the expansion from the Big Bang go into reverse, so that the universe ends in a Big Crunch? SUGGESTED READING The Big Bang didn't happen By Eric J.Lerner Physicists in the 19th century developing the science of thermodynamics observed that, as time passes, a complicated system like the universe becomes more disordered. (We say that its entropy increases.) It has recently been suggested that this is upside down; it is the increasing disorder of the universe which in some way causes time to pass. This is part of a movement in which the traditional units of space, time, matter and energy are replaced by information as the fundamental currency of the universe. But these are early days for such theories.None of this matters to us individually. The sun will expand and swallow the earth long before the universe reaches its end. But we have an insatiable curiosity to know the answer to Malunkyaputta's question. As the mathematician (and optimist) David Hilbert said, "Wir müssen wissen, Wir werden wissen" (We must know; we shall know.)References Apostolos Doxiadis, Logicomix, Bloomsbury, 2009.Carlo Rovelli, Reality is not what it seems, Riverside Books, 2017.
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Cosmology & The Universe
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October 06, 2022 02:11 PM Computer simulations created by scientists showcase alternate theories of how the moon was created through a giant impact, challenging the prevailing belief that the moon was formed from a disk of debris orbiting the Earth. The researchers from Durham University’s Institute for Computational Cosmology have released four different simulations showing that one object in space could have collided into another, creating the moon as we know it. The simulations showcase how most of the moon was formed immediately after the impact, meaning less of it became molten during its formation than in previous theories, according to EurekAlert. “This formation route could help explain the similarity in isotopic composition between the lunar rocks returned by the Apollo astronauts and Earth’s mantle," said Vincent Eke, one of the co-authors of the study. "There may also be observable consequences for the thickness of the lunar crust, which would allow us to pin down further the type of collision that took place.” WATCH: NASA SPACEX ROCKET TAKES ASTRONAUTS TO INTERNATIONAL SPACE STATION Scientists from Durham University’s Institute for Computational Cosmology used supercomputer simulations to reveal an alternative explanation for the Moon's origin, with a giant impact immediately placing a Moon-like body into orbit around Earth. Durham University The moon is believed to have formed after a collision between the young Earth and a Mars-sized object called Theia, with most theories claiming that the moon was created by the gradual accumulation of debris from the impact. However, this theory has been challenged by measurements of lunar rocks showing their composition is similar to Earth’s mantle, while the impact produced debris that came mostly from Theia. The researchers also found that when a satellite passes in close proximity to the Earth, it can actually be pushed into a wider orbit rather than getting torn apart by the “tidal forces” from Earth’s gravity. "We went into this project not knowing exactly what the outcomes of these very high-resolution simulations would be," said lead researcher Jacob Kegerreis. "So, on top of the big eye-opener that standard resolutions can give you wrong answers, it was extra exciting that the new results could include a tantalizingly Moon-like satellite in orbit." CLICK HERE TO READ MORE FROM THE WASHINGTON EXAMINER The team of researchers who worked on these simulations included scientists at NASA Ames Research Centre and the University of Glasgow. Their simulation findings have been published in the Astrophysical Journal Letters.
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Cosmology & The Universe
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Science Jul 11, 2022 6:37 PM EDT President Joe Biden on Monday revealed the very first full-color image from the James Webb Space Telescope, showing a stretch of space studded with thousands of galaxies. It’s the highest resolution image of the infrared universe anyone has ever seen.
Dubbed “Webb’s First Deep Field,” the image shows galaxy cluster SMACS 0723 in unprecedentedly clear detail.
“If you held a grain of sand on the tip of your finger at arm’s length, that is the part of the universe that you’re seeing [in this image] — just one little speck of the universe,” NASA Administrator Bill Nelson told the president during an event at the White House. “You’re seeing galaxies that are shining around other galaxies whose light has been bent.”
NASA will release more images and data on Tuesday from Webb, the largest and most powerful tool of its kind. Having taken more than three decades to create and launch, the telescope is designed to observe some of the oldest objects in the universe, as well as many that are less ancient and in closer proximity to Earth.
During a live broadcast at 10:30 a.m. EDT, amateur and professional astronomers alike can expect to be dazzled by the range of new images, which includes a nursery where stars are born, an gaseous planet beyond our solar system, a quintet of galaxies, and more, according to the space agency. The briefing will also include spectroscopic data that scientists use to determine characteristics of distant objects.
WATCH: Biden offers first peek of historic image from James Webb Space Telescope
Webb, a successor to the groundbreaking Hubble telescope that revolutionized our understanding of the cosmos, can be considered a kind of time machine, said John Mather, a senior astrophysicist at NASA and senior project scientist with the James Webb Space Telescope. That’s because Webb is receiving the light first emitted by different celestial objects, not as they are today.
“If you look at things really, really, really far away, then you’re looking pretty far back in time, so it starts to add up,” Mather added. “That’s why it’s important to us as scientists.”
Webb is a collaboration between NASA, the Canadian Space Agency (CSA) and the European Space Agency (ESA). It picks up on incredibly faint, ancient light that is still traveling from distant objects across our expanding universe. Over the course of its journey, the original wavelengths have shifted and stretched from visible or ultraviolet light to infrared in a process called cosmological redshift.
This engineering image represents a total of 32 hours of exposure time at several overlapping points. The observations were not optimized for detection of faint objects, but nevertheless the image captures extremely faint objects and was formerly the deepest image of the infrared sky. Image courtesy NASA, CSA and FGS team.
Prior to this week’s reveal, NASA published an image it had taken during an engineering test of the telescope’s ability to lock onto a target. The collection of stars and galaxies, which appears like amber studded with flares, is another testament to what we can expect from Webb as it kicks off its campaign to get the oldest possible snapshots of the universe.
This story is developing and will be updated. Left: The first image from NASA’s James Webb Space Telescope is the deepest and sharpest infrared image of the distant universe to date. Known as Webb’s First Deep Field, this image of galaxy cluster SMACS 0723 is overflowing with detail. Thousands of galaxies – including the faintest objects ever observed in the infrared – have appeared in Webb’s view for the first time. This slice of the vast universe covers a patch of sky approximately the size of a grain of sand held at arm’s length by someone on the ground. Image courtesy of NASA, ESA, CSA, and STScI
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Cosmology & The Universe
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Key pointsNASA to share first images from new James Webb Space TelescopePictures from the most powerful telescope in history due at 3.30pmThe very first image was revealed by President Biden on MondayAnalysis by Tom Clarke: Why is this such a big deal?Updates from Tom Clarke, science editor, and Jess Breadman, producer, at NASA Goddard. Live reporting by Emily Mee, live blogger, and Alexander Martin, technology reporter Telescope is 'next giant leap in astronomy' Lisa Campbell, president of the Canadian Space Agency, says the Webb telescope will provide "long-awaited answers to age-old questions". Very exciting. She goes as far as to say this is the "next giant leap in space astronomy", offering an "unprecedented view of the universe".The Canadian Space Agency has helped the effort by providing efforts that can keep the JWST perfectly aligned to "observe the earliest galaxies". How Biden helped the telescope to make it into space NASA administrator Bill Nelson has just taken the stage, writes our science and technology editor Tom Clarke. "You should have seen the president and vice president last night, they were like kids," he said. The administrator is friends with Joe Biden from his time as a congressman. That friendship is no small part of the fact the JWST made it into space at all. There were many moments over its 20-year development when Congress tried to axe the project. It hit several delays and costs exceeded $10bn. Yet somehow JWST was spared and scraped into space on Christmas Day before its budget crashed into another financial year. A statuette of the telescope is given a dusting off... How much better is JWST compared to Hubble? Dr Kelvin Getley has shared what he described as a rough comparison of the improvement between the images captured by the Hubble and James Webb space telescopes.Here are some of the other Hubble images that we're about to get updates on. Astronomers bursting with excitement after 'amazing teaser' Dr Nathan Adams, a research associate at the University of Manchester, said: "Within minutes I was awash with notifications from my colleagues about the noticeable improvement in depth compared to Hubble."With just a simple picture, people are already finding galaxies which previously didn't show up in the imaging we had of this patch of sky. I can't wait to see what we can do when we get hold of these images properly!"Dr Aayush Saxena, a research fellow in extragalactic astronomy at University College London, said: "It was incredible to see this stunning multi-colour image of the galaxy cluster, complete with beautiful 'arcs' that arise due to the bending of light from objects that lie behind massive clusters of galaxies."To be able to achieve such sensitivity and resolution at infrared wavelengths is truly paradigm shifting, opening up a whole range of possibilities. These capabilities will be revolutionary to detect some of the first galaxies to have formed in the Universe. "Overall, this was an amazing teaser of JWST's revolutionary capabilities, and I cannot wait to see more data." 'Absolute scenes' ahead of unveiling Our science and technology editor Tom Clarke is at the NASA Goddard Space Flight Centre in Maryland, where the new images are set to be revealed soon...There are some absolute scenes going on here. Eighteen NASA staff have just come into the room, each of them dressed as one of the 18 hexagonal mirrors that make James Webb's massive 6.5 metre-wide light-gathering mirror.It's that that will be bringing us these incredible images we should be getting in under an hour now. There's a real sense of genuine excitement in this room. It's filled with scientists, engineers, cosmologists, astrophysicists, the people who built the telescope, the people who are going to learn from the science, but there are also politicians. It's going to give us a completely new view of the universe. One of the images we're expecting to see today is likely to feature the oldest object ever imaged - maybe 13.23 billion years old. The first image 'a minor glimpse of what is to come' Yesterday's picture from the James Webb Space Telescope was "just the start of a marathon of amazing images that will reveal the deepest wonders of the universe", said Dr Hannah Wakeford."The first image is a minor glimpse of what is to come," added Dr Wakeford, an exoplanet specialist from the University of Bristol."Twelve and a half hours to look back over 13 billion years of time. In that image is thousands of galaxies, billions of stars and trillions of planets. How can you not be in awe?" How will the JWST help search for alien life? The James Webb Space Telescope is equipped with a powerful infrared telescope that is designed to "explore a wide range of science questions to us understand the origins of the universe and our place in it", says NASA."Webb will directly observe a part of space and time never seen before. Webb will gaze into the epoch when the very first stars and galaxies formed, over 13.5 billion years ago."Ultraviolet and visible light emitted by the very first luminous objects has been stretched or 'redshifted' by the universe’s continual expansion and arrives today as infrared light," adds NASA, and Webb's telescope is designed to detect that kind of light "with unprecedented resolution and sensitivity".The JWST is also going to be used "to study planets and other bodies in our solar system to determine their origin and evolution and compare them with exoplanets, planets that orbit other stars".Webb will also observe exoplanets located in their stars' habitable zones, the regions where a planet could harbour liquid water on its surface, and can determine if and where signatures of habitability may be present.It will use a technique called transmission spectroscopy to observe starlight filtered through planetary atmospheres.Because the molecules in the atmosphere absorb particular wavelengths of light, whatever gets filtered through will reveal the chemical compositions of those atmospheres, and potentially indicate if the planet is capable of harbouring life. President Biden presents first NASA image "That blows my mind... a million miles into the cosmos," he said. The deepest and sharpest infrared image of the universe to date The very first image captured by the James Webb Space Telescope was shared by President Biden on Monday evening.He described it as representing "a historic moment for science and technology" and "for astronomy and space exploration" - as well as "for America and all humanity".NASA administrator Bill Nelson said: "We're looking back more than 13 billion years... and we're going further... this is just the first image and since we know the universe is 13.8 billion years old, we're going back almost to the beginning."It is going to be so precise you are going to see whether or not planets are habitable. And when you look at something as big as this we're going to be able to answer questions that we don't even know what the questions are yet." Due to your consent preferences, you’re not able to view this. 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Cosmology & The Universe
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The James Webb space telescope has once more gazed into the bowels of the universe to produce one of the most mesmerizing images the world has ever seen. This time, the newly minted space telescope took a gander at the Orion Nebula. The result is a fantastic picture full of twinkling stars and vast wispy clouds. This is what the heart of the Orion Nebula looks like A complete look at the heart of the Orion Nebula as captured by James Webb. Image source: NASA, ESA, CSA, Data reduction and analysis : PDRs4All ERS Team; graphical processing S. Fuenmayor & O. BernéThe Orion Nebula has long been one of humankind’s most studied regions of space. Now, though, James Webb has given us a look at the Orion Nebula that we’ve never been given before. Where Hubble and other telescopes have looked at the nearby nebula in great detail before, James Webb’s NIRCam instrument has given us an even more detailed look at the nebula’s heart. The new image, which was released this month, was part of a targeted international collaboration, which included researchers from Western University. The image was originally captured using James Webb’s NIRCam instrument and then created using various filters and composites to create the image we now see. The result, of course, is something unreal. The Orion Nebula is located just 1,350 light-years away from Earth. Because of its relative closeness to Earth, the star-bearing nebula has been a study point for astronomers for decades. Now, though, we’re finally getting a detailed look at the nebula’s heart. With James Webb, we’re able to peer deep into the Orion Nebula and see various filaments, as well as young stars forming within it. A photo of the Orion Nebula as captured by the Hubble Space Telescope. Image source: NASA/JPL-Caltech STScIIt’s an intriguing view and one that wouldn’t be possible without the powerful hardware behind James Webb. This isn’t the first time we’ve looked at the nebula’s heart. Previously, Hubble has given us glimpses into the celestial spectacle. However, they’ve never returned with the amount of detail showcased here or even in Webb’s first images. Being able to peer so deeply into the universe and in such great detail will unlock new doors for learning and exploration. Scientists have already used James Webb to detect carbon dioxide on exoplanets, and they believe they may have found an inhabitable exoplanet recently, too. This James Webb image of the Orion Nebula is just a reminder of the telescope’s strength and scope.
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Cosmology & The Universe
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The James Webb space telescope has detected what appear to be six massive ancient galaxies, which astronomers are calling “universe breakers” because their existence could upend current theories of cosmology.
The objects date to a time when the universe was just 3% of its current age and are far larger than was presumed possible for galaxies so early after the big bang. If confirmed, the findings would call into question scientists’ understanding of how the earliest galaxies formed.
“These objects are way more massive than anyone expected,” said Joel Leja, an assistant professor of astronomy and astrophysics at Penn State University and a study co-author. “We expected only to find tiny, young, baby galaxies at this point in time, but we’ve discovered galaxies as mature as our own in what was previously understood to be the dawn of the universe.”
The observations come from the first dataset released from Nasa’s James Webb space telescope, which is equipped with infrared-sensing instruments capable of detecting light emitted by the most ancient stars and galaxies. While sifting through images, Dr Erica Nelson, of the University of Colorado Boulder, and a co-author, spotted a series of “fuzzy dots” that appeared unusually bright and unusually red.
Redness in astronomy is a proxy for age, because as light travels across the expanding universe it is stretched out, or red-shifted. These galaxies appeared to be roughly 13.5bn years old, placing them about 500m-700m years after the big bang.
These would not be the oldest galaxies observed by James Webb, which launched in December 2021. Last year, scientists spotted four galaxies that date to about 350m years after the big bang, but these were far smaller. Calculations suggest the latest galaxies harboured tens to hundreds of billions of sun-sized stars’ worth of mass, putting them on par with the Milky Way.
“It’s bananas,” said Nelson. “These galaxies should not have had time to form.”
Explaining the existence of such massive galaxies close to the dawn of time would require scientists to revisit either some basic rules of cosmology or the understanding of how the first galaxies were seeded from small clouds of stars and dust.
“It turns out we found something so unexpected it actually creates problems for science,” said Leja. “It calls the whole picture of early galaxy formation into question.”
Existing models suggest that after a period of rapid expansion, the universe spent a few hundred million years cooling down enough for gas to coalesce and collapse into the first stars and galaxies began to form, a period known as the dark ages.
“The discovery of such massive galaxies so soon after the big bang suggests that the dark ages may not have been so dark after all, and that the universe may have been awash with star formation far earlier than we thought,” said Dr Emma Chapman, an astrophysicist at the University of Nottingham, who was not involved in the latest observations.
Chapman said that further observations would be required to confirm the discovery before existing models could be abandoned. “Saying that, with the pace that JWST has been upturning theories and revolutionising whole fields, it wouldn’t surprise me if it were true!” she added.
The team are planning to obtain spectrum images of the massive galaxies, which can provide more accurate distance information and allow better estimates of their mass. “A spectrum will immediately tell us whether or not these things are real,” Leja said.
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Cosmology & The Universe
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When Thomas Hertog was first summoned to Stephen Hawking's office in the late 1990s, there was an instant connection between the young Belgian researcher and the legendary British theoretical physicist.
"Something clicked between us," Hertog said.
That connection would continue even as Hawking's debilitating disease ALS robbed him of his last ways to communicate, allowing the pair to complete a new theory that aims to turn how science looks at the universe on its head.
The theory, which would be Hawking's last before his death in 2018, has been laid out in full for the first time in Hertog's book "On the Origin of Time," published in the UK last month.
In an interview with AFP, the cosmologist spoke about their 20-year collaboration, how they communicated via facial expression, and why Hawking ultimately decided his landmark book "A Brief of History of Time" was written from the wrong perspective.
The 'designed' universe
During their first meeting at Cambridge University in 1998, Hawking wasted no time in bringing up the problem bothering him.
"The universe we observe appears designed," Hawking told Hertog, communicating via a clicker connected to a speech machine.
Hertog explained that "the laws of physics -- the rules on which the universe runs -- turn out to be just perfect for the universe to be habitable, for life to be possible."
This remarkable string of good luck stretches from the delicate balance that makes it possible for atoms to form molecules necessary for chemistry to the expansion of the universe itself, which allows for vast cosmic structures such as galaxies.
One "trendy" answer to this problem has been the multiverse, an idea that has recently become popular in the movie industry, Hertog said.
This theory explains away the seemingly designed nature of the universe by making it just one of countless others -- most of which are "crap, lifeless, sterile," the 47-year-old added.
But Hawking realized the "great mire of paradoxes the multiverse was leading us into," arguing there must be a better explanation, Hertog said.
Outsider's perspective
A few years into their collaboration, "it began to sink in" that they were missing something fundamental, Hertog said.
The multiverse and even "A Brief History of Time" were "attempts to describe the creation and evolution of our universe from what Stephen would call a 'God's eye perspective'," Hertog said.
But because "we are within the universe" and not outside looking in, our theories cannot be decoupled from our perspective, he added.
"That was why (Hawking) said that 'A Brief History of Time' is written from the wrong perspective."
For the next 15 years, the pair used the oddities of quantum theory to develop a new theory of physics and cosmology from an "observer's perspective."
But by 2008, Hawking had lost the ability to use his clicker, becoming increasingly isolated from the world.
"I thought it was over," Hertog said.
Then the pair developed a "somewhat magical" level of non-verbal communication that allowed them to continue working, he said.
Positioned in front of Hawking, Hertog would ask questions and look into the physicist's eyes.
"He had a very wide range of facial expressions, ranging from extreme disagreement to extreme excitement," he said.
"It's impossible to disentangle" which parts of the final theory came from himself or Hawking, Hertog said, adding that many of the ideas had been developed between the pair over the years.
'One grand evolutionary process'
Their theory is focused on what happened in the first moments after the Big Bang.
Rather than an explosion that followed a pre-existing set of rules, they propose that the laws of physics evolved along with the universe.
This means that if you turn back the clock far enough, "the laws of physics themselves begin to simplify and disappear," Hertog said.
"Ultimately, even the dimension of time evaporates."
Under this theory, the laws of physics and time itself evolved in a way that resembles biological evolution -- the title of Hertog's book is a reference to Darwin's "On the Origin of Species."
"What we're essentially saying is that (biology and physics) are two levels of one grand evolutionary process," Hertog said.
He acknowledged that it is difficult to prove this theory because the first years of the universe remain "hidden in the mist of the Big Bang."
One way to lift this veil could be by studying gravitational waves, ripples in the fabric of space time, while another could be via quantum holograms constructed on quantum computers, he said.
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Cosmology & The Universe
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Einstein's theory of gravity — general relativity — has been very successful for more than a century. However, it has theoretical shortcomings. This is not surprising: the theory predicts its own failure at spacetime singularities inside black holes — and the Big Bang itself.
Unlike physical theories describing the other three fundamental forces in physics — the electromagnetic and the strong and weak nuclear interactions — the general theory of relativity has only been tested in weak gravity.
Deviations of gravity from general relativity are by no means excluded nor tested everywhere in the universe. And, according to theoretical physicists, deviation must happen.
Deviations and quantum mechanics
According to Einstein, our universe originated in a Big Bang. Other singularities hide inside black holes: Space and time cease to have meaning there, while quantities such as energy density and pressure become infinite. These signal that Einstein’s theory is failing there and must be replaced with a more fundamental one.
Naively, spacetime singularities should be resolved by quantum mechanics, which apply at very small scales.
Quantum physics relies on two simple ideas: point particles make no sense; and the Heisenberg uncertainty principle, which states that one can never know the value of certain pairs of quantities with absolute precision — for example, the position and velocity of a particle. This is because particles should not be thought of as points but as waves; at small scales they behave as waves of matter.
This is enough to understand that a theory that embraces both general relativity and quantum physics should be free of such pathologies. However, all attempts to blend general relativity and quantum physics necessarily introduce deviations from Einstein’s theory.
Therefore, Einstein’s gravity cannot be the ultimate theory of gravity. Indeed, it was not long after the introduction of general relativity by Einstein in 1915 that Arthur Eddington, best known for verifying this theory in the 1919 solar eclipse, started searching for alternatives just to see how things could be different.
Einstein’s theory has survived all tests to date, accurately predicting various results from the precession of Mercury’s orbit to the existence of gravitational waves. So, where are these deviations from general relativity hiding?
Cosmology matters
A century of research has given us the standard model of cosmology known as the Λ-Cold Dark Matter (ΛCDM) model. Here, Λ stands for either Einstein’s famous cosmological constant or a mysterious dark energy with similar properties.
Dark energy was introduced ad hoc by astronomers to explain the acceleration of the cosmic expansion. Despite fitting cosmological data extremely well until recently, the ΛCDM model is spectacularly incomplete and unsatisfactory from the theoretical point of view.
In the past five years, it has also faced severe observational tensions. The Hubble constant, which determines the age and the distance scale in the universe, can be measured in the early universe using the cosmic microwave background and in the late universe using supernovae as standard candles.
These two measurements give incompatible results. Even more important, the nature of the main ingredients of the ΛCDM model — dark energy, dark matter and the field driving early universe inflation (a very brief period of extremely fast expansion originating the seeds for galaxies and galaxy clusters) — remains a mystery.
From the observational point of view, the most compelling motivation for modified gravity is the acceleration of the universe discovered in 1998 with Type Ia supernovae, whose luminosity is dimmed by this acceleration. The ΛCDM model based on general relativity postulates an extremely exotic dark energy with negative pressure permeating the universe.
Problem is, this dark energy has no physical justification. Its nature is completely unknown, although a plethora of models has been proposed. The proposed alternative to dark energy is a cosmological constant Λ which, according to quantum-mechanical back-of-the-envelope (but questionable) calculations, should be huge.
However, Λ must instead be incredibly fine-tuned to a tiny value to fit the cosmological observations. If dark energy exists, our ignorance of its nature is deeply troubling.
Alternatives to Einstein’s theory
Could it be that troubles arise, instead, from wrongly trying to fit the cosmological observations into general relativity, like fitting a person into a pair of trousers that are too small? That we are observing the first deviations from general relativity while the mysterious dark energy simply does not exist?
This idea, first proposed by researchers at the University of Naples, has gained tremendous popularity while the contending dark energy camp remains vigorous.
There is now a large literature on theories of gravity alternative to general relativity, going back to Eddington’s 1923 early investigations. A very popular class of alternatives is the so-called scalar-tensor gravity. It is conceptually very simple since it only introduces one additional ingredient (a scalar field corresponding to the simplest, spinless, particle) to Einstein’s geometric description of gravity.
The consequences of this program, however, are far from trivial. A striking phenomenon is the “chameleon effect,” consisting of the fact that these theories can disguise themselves as general relativity in high-density environments (such as in stars or in the solar system) while deviating strongly from it in the low-density environment of cosmology.
As a result, the extra (gravitational) field is effectively absent in the first type of systems, disguising itself as a chameleon does, and is felt only at the largest (cosmological) scales.
The current situation
Nowadays the spectrum of alternatives to Einstein gravity has widened dramatically. Even adding a single massive scalar excitation (namely, a spin-zero particle) to Einstein gravity —and keeping the resulting equations “simple” to avoid some known fatal instabilities — has resulted in the much wider class of Horndeski theories, and subsequent generalizations.
Theorists have spent the last decade extracting physical consequences from these theories. The recent detections of gravitational waves have provided a way to constrain the physical class of modifications of Einstein gravity allowed.
However, much work still needs to be done, with the hope that future advances in multi-messenger astronomy lead to discovering modifications of general relativity where gravity is extremely strong.
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Cosmology & The Universe
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Dubbed “Webb’s First Deep Field,” it is the first full-color image from the $10 billion observatory that launched into space last year.This image, known as "Webb's First Deep Field," is the first full-color image released from the next-generation James Webb Space Telescope. It is the sharpest infrared image of the distant universe ever produced, according to NASA.Space Telescope Science Institut / NASA, ESA, CSA, STScI, Webb ERO July 11, 2022, 10:23 PM UTCThe first image from NASA's James Webb Space Telescope offered humanity a stunning new view of the universe on Monday — a first-of-its-kind infrared image so distant in the cosmos that it shows stars and galaxies as they appeared 13 billion years ago.President Joe Biden revealed the new image Monday at the White House alongside NASA Administrator Bill Nelson. Dubbed "Webb's First Deep Field," it is the first full-color image from the $10 billion observatory that launched into space last year, and the highest-resolution infrared view of the universe yet captured.In a news briefing last month to preview the image, Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate, said it will likely represent a turning point in humanity's understanding of the cosmos."It's not an image. It's a new worldview," Zurbuchen said at the time.The image offers a glimpse of the universe as it was 13 billion years ago. Telescopes essentially function as time machines because it takes time for light to travel through space. As such, light that reaches the Webb telescope from the most distant galaxies in the universe does not show present conditions but rather provide insights into how the universe was billions of years ago.Scientists have said that the James Webb Space Telescope could unlock mysteries from as far back as 100 million years after the Big Bang.The Webb observatory's infrared “eyes” allow it to see distant stars and galaxies beyond the range of human sight and other telescopes, such as the Hubble Space Telescope, that see primarily visible light.Infrared instruments are better suited for trying to detect the universe’s earliest stars and galaxies because the longer wavelengths of infrared light can pierce through dust and gas that might otherwise obscure some celestial objects. Since the universe is also expanding, light from the earliest stars and galaxies is stretched, shifting into longer infrared wavelengths undetectable by Hubble or the human eye.In a separate event on Tuesday, NASA will release more images from the Webb telescope, including the observatory's first spectrum of an exoplanet, showing light emitted at different wavelengths from a planet in another star system. These types of observations could help scientists search for signs of life beyond Earth.The James Webb Space Telescope is a collaboration among NASA, the European Space Agency and the Canadian Space Agency. The tennis court-sized observatory is designed to study the early days after the Big Bang and help astronomers piece together how the modern universe came to be.Denise Chow is a reporter for NBC News Science focused on general science and climate change.
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Cosmology & The Universe
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| July 11, 2022 04:56 PM | Updated Jul 11, 2022, 07:34 PM President Joe Biden and Vice President Kamala Harris unveiled one of the first images captured by the James Webb Space Telescope on Monday, hailed as the "deepest" and sharpest infrared image of the universe ever produced. The image covers a "patch of sky approximately the size of a grain of sand held at arm’s length by someone on the ground" and shows thousands of galaxies "in a tiny sliver of vast universe," according to NASA. BIDEN TO UNVEIL JAMES WEBB SPACE TELESCOPE'S FIRST PHOTO AT WHITE HOUSE "Today represents an exciting new chapter in the exploration of our universe. From the beginning of history, humans have looked up to the night sky with wonder, and thanks to the dedication of people who have been working for decades in engineering and on scientific marvels, we can look to the sky with new understanding," Harris said during a NASA briefing at the White House. "The James Webb Space Telescope allows us to see deeper into space than ever before, and in stunning clarity. It will enhance what we know about the origins of our universe, our solar system, and possibly life itself." The image unveiled on Monday is of "galaxy cluster SMACS 0723" and is the first of five full-color images from the telescope that will be released by NASA, the European Space Agency, and the Canadian Space Agency. The rest will be disclosed to the public on Tuesday. The telescope embodies how "America leads the world, not by the example of our power, but the power of our example," Biden said. "These images are going to remind the world that America can do big things and to remind the American people, especially our children, that there's nothing beyond our capacity," Biden said. The first image from the Webb Space Telescope represents a historic moment for science and technology. For astronomy and space exploration.And for America and all humanity. pic.twitter.com/cI2UUQcQXj— President Biden (@POTUS) July 11, 2022 Using infrared light, the telescope is able to see through cosmic dust, allowing scientists to better see the first galaxies and stars to form in the universe. The telescope, developed by NASA and Northrop Grumman, is the largest and most powerful space telescope ever built, costing nearly $10 billion dollars and taking over 20 years to assemble. It was launched into space in December 2021 after a series of delays. NASA Administrator Bill Nelson said the image unveiled on Monday was the first of many from a tool that will enable scientists to look at the chemical composition of planets to ultimately determine if they are "habitable." "This is just the first image. They're going back about 13.5 billion years. And since we know the universe is 13.8 billion years old, we're going back almost to the beginning," Nelson said. Earlier this year, test images from the telescope, including its first "selfie" from space, were released while it was still in its commissioning phase, according to CNN. CLICK HERE TO READ MORE FROM THE WASHINGTON EXAMINER NASA released a list of five cosmic targets for the telescope's first images last Friday, including the Carina Nebula, one of the largest and brightest nebulae in the sky, located approximately 7,600 light-years away from Earth; the WASP-96b exoplanet, located 1,150 light-years from Earth; the Southern Ring Nebula, an expanding cloud of gas surrounding a dying star approximately 2,000 light-years away; Stephan’s Quintet, the first compact galaxy group ever discovered in 1877, located about 290 million light-years away; and SMACS 0723.
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Cosmology & The Universe
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An international investigation, led by the Instituto de Astrofísica de Canarias (IAC) and the University of La Laguna (ULL), finds the first evidence of a massive galaxy without dark matter, which defies the current standard of cosmology. According to an IAC note, this is the first time that a massive galaxy (with several times the mass of the Milky Way) has been found without there being evidence of this invisible component of the Universe.
“This result has no place within the current paradigm of the cosmological model with dark matter”, explains Sébastien Comerón, who has directed the research.
The standard cosmological model postulates that massive galaxies contain large amounts of dark matter, a type of matter that is transparent and does not interact with ordinary matter, but whose existence can be inferred from the gravitational pull it exerts on stars and the gas, which is observable. The note explains that NGC 1277 is known to be a prototype ‘relic galaxy’, that is, a galaxy that has not interacted with any of its neighbors. These galaxies are extremely rare and are considered unevolved remnants of what were giant galaxies at the dawn of the Universe. “The importance of relic galaxies in understanding how the first galaxies formed was the reason why we decided to observe NGC 1277 with an integral field spectrograph,” says Comerón.
From these spectra, kinematic maps were obtained with which they reconstructed the mass distribution of the galaxy within a radius of about 20,000 light years, explains the scientist. The team has found that the mass distribution of NGC 1277 corresponds to that of stars, so it follows that, within the sampled radius, there could be at most 5 percent dark matter, although the observations are consistent with the non-existence of this component.
However, cosmological models predict that a galaxy with the mass of NGC 1277 should have a dark matter fraction of at least 10% and up to 70%. “This discrepancy between the observation and what is expected is an enigma and may be a challenge for the standard model”, points out Ignacio Trujillo, a researcher at the IAC and the ULL who has participated in this study published in the specialized journal Astronomy & Astrophysics.
The study proposes two possible explanations for the lack of dark matter in NGC 1277. “One is that the gravitational interaction with the environment of the cluster of galaxies in which it is found has ripped out the dark matter,” says Anna Ferré-Mateu, a researcher at the IAC and the ULL who has also participated in the study, and another is that the dark matter was expelled from the system when it formed by the merger of protogalactic fragments that gave rise to the relic galaxy. For the authors of the study, none of these explanations is entirely satisfactory, “with which the enigma of how a massive galaxy can be formed without dark matter remains open,” Comerón emphasizes.
In order to further investigate this mystery, the team plans to make new observations with the WEAVE instrument of the William Herschel Telescope (WHT), located at the Roque de los Muchachos Observatory, on La Palma. If the result that NGC 1277 does not have dark matter is confirmed, the discovery would call into question alternative models of dark matter, that is, modified gravity theories that explain that much of the gravitational attraction between galaxies is due to slightly altered gravity rules, adds the IAC.
source:https://www.aanda.org/articles/aa/full_html/2023/07/aa46291-23/aa46291-23.html
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Cosmology & The Universe
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Astronomers have spotted the most distant fast radio burst (FRB) to date in a galaxy so far away that its light took eight billion years to reach Earth.
The remote blast of cosmic radio waves, whose source was detected by the European Southern Observatory's (ESO) Very Large Telescope (VLT), lasted less than a millisecond.
It released the equivalent of the Sun's total emission over 30 years, in a tiny fraction of a second, making it one of the most energetic FRBs ever observed, scientists said.
FRBs are super intense, millisecond-long bursts of radio waves produced by unidentified sources in the distant cosmos.
They were discovered in 2007 by American astronomer Duncan Lorimer, Science Alert said on its website.
Only a few dozen similar events have been observed in data collected by radio telescopes around the world and it is not known what causes them, the Science journal said on its website.
Most last just a few milliseconds and are never seen again, but two are known to have repeated their emissions.
The discovery confirms that FRBs can be used to measure the missing matter between galaxies, offering a new way to weigh the Universe, the research team said.
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At the moment, the methods used to gauge the mass of the Universe give conflicting answers and challenge the standard model of cosmology.
Professor Ryan Shannon, of the Swinburne University of Technology in Australia, who co-led the study, said: "If we count up the amount of normal matter in the Universe - the atoms that we are all made of - we find that more than half of what should be there today is missing.
"We think that the missing matter is hiding in the space between galaxies, but it may just be so hot and diffuse that it's impossible to see using normal techniques."
"Even in space that is nearly perfectly empty they can 'see' all the electrons, and that allows us to measure how much stuff is between the galaxies."
The burst, named FRB 20220610A, was discovered in June last year by the ASKAP radio telescope in Australia.
Stuart Ryder, an astronomer from Macquarie University in Australia and the co-lead author of the study, said the burst was "older and further away than any other FRB source found to date and likely within a small group of merging galaxies".
The findings are published in the Science journal.
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Cosmology & The Universe
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NASA released the first batch of pictures from the James Webb Space Telescope on Tuesday. These glimpses into space are utterly breathtaking and showcase the beauty of the universe. As a grand finale during its livestream, the National Aeronautics and Space Administration released a picture of the Carina Nebula that was by far the most visually stunning picture in the collection. Thanks to the combined work of NASA, the European Space Agency, the Canadian Space Agency, and Northrop Grumman, pictures of our universe are being distributed across the world for everyone to see. When a telescope is able to see galaxies that are 13.5 billion years old, those responsible for such a technological accomplishment deserve all the recognition possible. Let’s not take these developments for granted. Former President John F. Kennedy asked the U.S. Congress to support the rapid expansion of the nation’s space program in 1961. Before Neil Armstrong stepped on the moon in 1969, people mostly did not support Kennedy’s space race. A 1967 Harris poll reported that 54% of respondents did not believe the $4 billion price tag for a moon landing was worth it. NASA is now the pride and joy of the people. A 2018 Pew Research Center poll found that 72% of adults believe it is “essential” for the United States to lead the world in space exploration. In another question, 80% said the International Space Station was a good investment for the nation. Despite widespread public support for America’s space programs, Sen. Bernie Sanders (I-VT) proposed cutting funding for a new lunar lander in April 2022. Established under former President Donald Trump, the Space Force is another department that was controversial in its early years. CNN polling in 2018 found that 55% of Americans opposed the creation of a Space Force. But when President Joe Biden decided to keep the Space Force rather than abolish it, a majority supported his decision. A highly effective partnership with the private sector is driving the modern space race. In a first since 2011, NASA and SpaceX launched a crewed mission to the ISS from U.S. soil on May 30, 2020. SpaceX launched 46 Starlink satellites before proceeding to land the first stage of the rocket at sea on Sunday. Private sector innovation is creating cleaner and more efficient products that allow us to reach the stars more frequently than before. If you’re not sold on space missions, just look at how the rest of the world is being affected by it. Starlink keeps Ukraine connected to broadband services while they fight against Russia’s forces. Satellites allow the U.S. and its European allies to monitor changes in the atmosphere, making them a crucial part of the fight against climate change. As you look at the latest pictures from the James Webb Space Telescope, remember that success was never guaranteed. Men and women have died in freak accidents during launches in pursuit of seeing what is now plastered all across social media. Humanity is continuing to reach new heights and see new corners of the universe, thanks to the ingenuity of NASA and our private sector. Our universe is an endless frontier, and efforts to explore it should continue to unite the nation regardless of our various backgrounds. James Sweet is a summer 2022 Washington Examiner fellow.
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Cosmology & The Universe
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Black Holes Formation and Detection Methods
Black holes are objects in space with such strong gravitational force that nothing can escape their pull, not even light. They form when a massive star runs out of fuel and collapses in on itself, creating a singularity at the center. Scientists study black holes by observing their effects on surrounding matter, such as the way they distort light and cause stars to orbit around them. Various methods are used to detect black holes, including observing X-rays and gamma rays emitted by matter as it falls into the black hole’s accretion disk, as well as observing the gravitational effects of the black hole on nearby stars and galaxies.
Gravity and Sound Waves Relationship
Gravity and sound waves are related through the concept of spacetime curvature. In Einstein’s theory of general relativity, gravity is explained as the curvature of spacetime caused by massive objects. This curvature can also affect the propagation of sound waves, leading to phenomena such as gravitational waves.
Black Holes and Sound Production
Black holes can produce sound waves through the vibration of matter in their accretion disks, which can generate sound waves that are then transmitted through the surrounding gas. However, these sound waves are at frequencies far too low for human ears to detect, and their detection requires sophisticated equipment such as gravitational wave detectors.
Other Emissions from Black Holes
In addition to sound waves, black holes can emit other forms of radiation, such as X-rays and gamma rays, as matter falls into the accretion disk and heats up to extremely high temperatures. These emissions can provide valuable information about the black hole’s properties and behavior.
Theoretical Models and Observations
Theoretical models of black holes predict their behavior and properties, including their ability to produce sound waves. Observations of black holes have generally been consistent with these theoretical predictions, although some discrepancies remain.
Implications of Black Hole Sound Production
The detection of sound waves from black holes could provide new insights into their properties and behavior, as well as into the fundamental physics of spacetime curvature and gravity. It could also have practical applications in fields such as astronomy and cosmology.
Future Research
Further research is needed to better understand the relationship between black holes and sound, including the mechanisms by which sound waves are generated and transmitted. New technologies and methods may be developed to explore this area further, including the development of more sensitive gravitational wave detectors and other instruments capable of detecting low-frequency sound waves.
Deep Dive
- Hawking, S. W. (1974). Black hole explosions? Nature, 248(5443), 30-31.
- Narayan, R., & McClintock, J. E. (2013). Observational evidence for black holes. New Journal of Physics, 15(1), 1-39.
- Rees, M. (1984). Black hole models for active galactic nuclei. Annual Review of Astronomy and Astrophysics, 22(1), 471-506.
- Thorne, K. S. (1994). Black holes and time warps: Einstein’s outrageous legacy. WW Norton & Company.
- Blandford, R. D., & Begelman, M. C. (1999). On the fate of gas accreting at a low rate onto a black hole. Monthly Notices of the Royal Astronomical Society, 303(1), L1-L5.
- Kormendy, J., & Ho, L. C. (2013). Coevolution (or not) of supermassive black holes and host galaxies. Annual Review of Astronomy and Astrophysics, 51(1), 511-653.
- Abramowicz, M. A., et al. (2004). Astrophysical evidence for the existence of black holes. Living Reviews in Relativity, 7(1), 1-79.
- Bambi, C. (2017). Black holes: a laboratory for testing strong gravity. Reviews of Modern Physics, 89(2), 025001.
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Cosmology & The Universe
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Published September 6, 2022 12:19PM Updated 1:28PM article In this mosaic image stretching 340 light-years across, Webb’s Near-Infrared Camera (NIRCam) displays the Tarantula Nebula star-forming region in a new light, including tens of thousands of never-before-seen young stars that were previously shrouded NASA’s James Webb Space Telescope continues to capture eye-popping images of the cosmos, with its latest showing fantastic detail of thousands of young stars spotted in a stellar nursery nicknamed the "Tarantula Nebula." A stellar nursery is an area of outer space within a dense nebula in which gas and dust are contracting, resulting in the formation of stars. The Tarantula Nebula received its spidery nickname for the appearance of its dusty filaments in previous telescope images, according to NASA. Also called 30 Doradus, the Tarantula Nebula is located 161,000 light-years away from Earth in the Large Magellanic Cloud galaxy. It’s home to the hottest, most massive stars known, according to the agency. In addition to the young stars, JWST’s new image revealed distant background galaxies, as well as the detailed structure and composition of the nebula’s gas and dust, NASA explained in a post titled, "A Cosmic Tarantula, Caught by NASA’s Webb. The $10 billion space telescope uses an infrared light spectrum that allows it to see through the cosmic dust and see faraway light from the corners of the universe. At the longer wavelengths of light captured by its Mid-Infrared Instrument (MIRI), Webb focuses on the area surrounding the central star cluster and unveils a very different view of the Tarantula Nebula. In this light, the young hot stars of the clus NASA said one of the reasons the Tarantula Nebula is of interest to astronomers is because the nebula has a similar type of chemical composition as the gigantic star-forming regions observed when the universe was only a few billion years old and star formation was at its peak — also called the "cosmic noon." "Star-forming regions in our Milky Way galaxy are not producing stars at the same furious rate as the Tarantula Nebula, and have a different chemical composition," the agency said in the post. "This makes the Tarantula the closest (i.e., easiest to see in detail) example of what was happening in the universe as it reached its brilliant high noon." A side-by-side display of the same region of the Tarantula Nebula brings out the distinctions between Webb’s near-infrared (closer to visible red, left) and mid-infrared (further from visible red, right) images. Each portion of the electromagnetic sp JWST will allow astronomers to compare observations of star formation in the Tarantula Nebula with the telescope’s deep observations of distant galaxies from the actual era of cosmic noon. "Despite humanity’s thousands of years of stargazing, the star-formation process still holds many mysteries – many of them due to our previous inability to get crisp images of what was happening behind the thick clouds of stellar nurseries," NASA said. "Webb has already begun revealing a universe never seen before, and is only getting started on rewriting the stellar creation story." JWST’s previous eye-popping images NASA astrophysicist shares details on set of James Webb Space Telescope images NASA shared four more images from the $10-billion telescope’s initial outward gazes, including two images of nebulas where stars are born and die in spectacular beauty and another shot showing an update of a classic image of five tightly clustered galaxies that dance around each other. In July, NASA’s $10 billion telescope shared its first view — offering the farthest humanity has ever seen in both time and distance. The image is filled with lots of stars, with massive galaxies in the foreground and faint and extremely distant galaxies peeking through here and there. Part of the image is light from not too long after the Big Bang, which was 13.8 billion years ago. NASA’s James Webb Space Telescope has produced the deepest and sharpest infrared image of the distant universe to date. Known as Webb’s First Deep Field, this image of galaxy cluster SMACS 0723 is overflowing with detail. Thousands of galaxies – incl (NASA, ESA, CSA, and STScI) Other images released that month show images show a dying star with a foamy edge of escaping gas, located about 2,500 light-years away, as well as five galaxies in a cosmic dance, called "Stephan’s Quintet." In another, the telescope used its infrared detectors to look at the chemical composition of a giant planet called WASP-96b. It’s about the size of Saturn and is 1,150 light-years away. It showed water vapor in the super-hot planet’s atmosphere and even found the chemical spectrum of neon, showing clouds where astronomers thought there were none. NASA’s James Webb Space Telescope reveals emerging stellar nurseries and individual stars in the Carina Nebula that were previously obscured. Images of "Cosmic Cliffs" showcase Webb’s cameras’ capabilities to peer through cosmic dust, shedding new light on how stars form. Image credit: NASA, ESA, CSA, and STScI The world’s biggest and most powerful space telescope rocketed away last December from French Guiana in South America. It reached its lookout point 1 million miles from Earth in January. Then the lengthy process began to align the mirrors, get the infrared detectors cold enough to operate, and calibrate the science instruments, all protected by a sunshade the size of a tennis court that keeps the telescope cool. Webb is considered the successor to the highly successful, but aging Hubble Space Telescope. Hubble has stared as far back as 13.4 billion years. Astronomers measure how far back they look in light-years with one light-year being 5.8 trillion miles. The plan is to use the telescope to peer back so far that scientists will get a glimpse of the early days of the universe about 13.7 billion years ago and zoom in on closer cosmic objects, even our own solar system, with a sharper focus. RELATED: NASA releases stunning new images of Phantom Galaxy from Hubble, James Webb telescopes This story was reported from Cincinnati. The Associated Press contributed.
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Cosmology & The Universe
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When two black holes collide into each other to form a new bigger black hole, they violently roil spacetime around them, sending ripples called gravitational waves outward in all directions. Previous studies of black hole collisions modeled the behavior of the gravitational waves using what is known as linear math, which means that the gravitational waves rippling outward did not influence, or interact, with each other. Now, a new analysis has modeled the same collisions in more detail and revealed so-called nonlinear effects.
"Nonlinear effects are what happens when waves on the beach crest and crash" says Keefe Mitman, a Caltech graduate student who works with Saul Teukolsky (PhD '74), the Robinson Professor of Theoretical Astrophysics at Caltech with a joint appointment at Cornell University. "The waves interact and influence each other rather than ride along by themselves. With something as violent as a black hole merger, we expected these effects but had not seen them in our models until now. New methods for extracting the waveforms from our simulations have made it possible to see the nonlinearities."
Keefe Mitman explains what it means to find nonlinear effects in models of black hole mergers.
The research, published in the journal Physical Review Letters, come from a team of researchers at Caltech, Columbia University, University of Mississippi, Cornell University, and the Max Planck Institute for Gravitational Physics.
In the future, the new model can be used to learn more about the actual black hole collisions that have been routinely observed by LIGO (Laser Interferometer Gravitational-wave Observatory) ever since it made history in 2015 with the first direct detection of gravitational waves from space. LIGO will turn back on later this year after getting a set of upgrades that will make the detectors even more sensitive to gravitational waves than before.
Mitman and his colleagues are part of a team called the Simulating eXtreme Spacetimes collaboration, or SXS. Founded by Teukolsky in collaboration with Nobel Laureate Kip Thorne (BS '62), Richard P. Feynman Professor of Theoretical Physics, Emeritus, at Caltech, the SXS project uses supercomputers to simulate black hole mergers. The supercomputers model how the black holes evolve as they spiral together and merge using the equations of Albert Einstein's general theory of relativity. In fact, Teukolsky was the first to understand how to use these relativity equations to model the "ringdown" phase of the black hole collision, which occurs right after the two massive bodies have merged.
"Supercomputers are needed to carry out an accurate calculation of the entire signal: the inspiral of the two orbiting black holes, their merger, and the settling down to a single quiescent remnant black hole," Teukolsky says. "The linear treatment of the settling down phase was the subject of my PhD thesis under Kip quite a while ago. The new nonlinear treatment of this phase will allow more accurate modeling of the waves and eventually new tests of whether general relativity is, in fact, the correct theory of gravity for black holes."
The SXS simulations have proved instrumental in identifying and characterizing the nearly 100 black hole mergers detected by LIGO so far. This new study represents the first time that the team has identified nonlinear effects in simulations of the ringdown phase.
"Imagine there are two people on a trampoline," Mitman says. "If they jump gently, they shouldn't influence the other person that much. That's what happens when we say a theory is linear. But if one person starts bouncing with more energy, then the trampoline will distort, and the other person will start to feel their influence. This is what we mean by nonlinear: the two people on the trampoline experience new oscillations because of the presence and influence of the other person."
In gravitational terms, this means that the simulations produce new types of waves. "If you dig deeper under the large waves, you will find an additional new wave with a unique frequency," Mitman says.
In the big picture, these new simulations will help researchers to better characterize future black hole collisions observed by LIGO and to better test Einstein's general theory of relativity.
Says co-author Macarena Lagos of Columbia University, "This is a big step in preparing us for the next phase of gravitational-wave detection, which will deepen our understanding of gravity in these incredible phenomena taking place in the far reaches of the cosmos."
The study titled "Nonlinearities in black hole ringdowns," was funded by the Sherman Fairchild Foundation, National Science Foundation, the Innovative Theoretical Cosmology Fellowship of Columbia University, the Department of Energy, and the Simons Foundation. Other Caltech-affiliated authors include Sizheng Ma, Yanbei Chen, Nils Deppe, François Hébert, Jordan Moxon, and Mark Scheel. Additional authors include Leo Stein (BS '06), Lam Hui, Lawrence Kidder, William Throwe, and Nils Vu.
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Cosmology & The Universe
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Spin me round: Conceptual image of the distant galaxy MACS1149-JD1 forming and spinning up to speed in the early universe. (Courtesy: ALMA (ESO/NAOJ/NRAO)) One of the most distant galaxies ever observed is very likely to be rotating, say astronomers. An international team led by Tsuyoshi Tokuoka of Waseda University, Japan, discovered the motion using observations from the Atacama Large Millimetre/submillimetre Array (ALMA) in Chile. The result offers crucial new insights into the evolution of newly-formed galaxies and could provide useful guidance for upcoming observations with the James Webb Space Telescope (JWST).
When galaxies first began to form, the universe was in its “dark ages” – a period when virtually all matter was cool and transparent. As matter collapsed under gravity, galaxies formed, kicking off star formation in nascent galactic centres and triggering the so-called “epoch of reionization” that ended the dark ages. From there, star formation spread out into rotating galactic disks, where newer stars now reside.
Astronomers still have much to learn about the physics that governed these ancient galaxies. To shed new light on these questions, including the origins of the galactic rotation, Tokuoka and colleagues turned to observations from ALMA. This instrument has revolutionized the observation of distant, highly redshifted galaxies, owing to its impressive spatial and frequency resolutions.
In the latest study, the researchers used ALMA to study MACS1149-JD1: a gravitationally lensed galaxy which lies over 10 billion light-years away, making it one of the most distant objects ever confirmed. Through spectroscopy, astronomers have discovered that JD1 contains a population of stars roughly 300 million years old, placing its origins well inside the universe’s dark ages – just 270 million years after the Big Bang.
Different redshifts
The team examined the characteristic wavelengths emitted by doubly ionized oxygen (O III) in JD1. This gas is widely found in supernova remnants, making it a key component of material in the interstellar medium. Thanks to ALMA’s resolution, the team was able to identify variations in the redshift of O III emissions in different parts of the galaxy. This revealed a gradient in the velocity of material in JD1’s interstellar medium – with one side of the galaxy displaying a distinctly different redshift.
This observation satisfied nearly all criteria that must be met to confirm that a galaxy is rotating, making it the earliest example of a rotating disk ever discovered. Its rotational speed was also far slower than is found in other galaxies, including our own – suggesting that JD1’s rotational motion is still in its early stages. Read more Galaxy rotation study rules out modified gravity, or does it? The result, which is described in The Astrophysical Journal Letters, means that astronomers have a record of galactic rotation speeds spanning over 95% of the universe’s total history, which members of the team say is an important step in understanding of how the physical characteristics of galaxies evolve. Tokuoka and colleagues now hope that many remaining questions will soon be answered with the help of the JWST, which should enable them to identify the ages of specific stellar populations inside the galaxy.
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Cosmology & The Universe
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By Daniel Brown, Trent UniversityIf you ask yourself what the biggest threat to human existence is you’d probably think of nuclear war, global warming or a large-scale pandemic disease. But assuming we can overcome such challenges, are we really safe?Living on our blue little planet seems safe until you are aware of what lurks in space. The following cosmic disasters are just a few ways humanity could be severely endangered or even wiped out. Happy reading!1. High energy solar flareOur sun is not as peaceful a star as one might initially think. It creates strong magnetic fields that generate impressive sun spots, sometimes many times larger than Earth. It also ejects a stream of particles and radiation – the solar wind. If kept in check by Earth’s magnetic field, this wind can cause beautiful northern and southern lights. But when it becomes stronger, it can also influence radio communication or cause power outages.The most powerful magnetic solar storm documented hit Earth in 1859. The incident, called the Carrington Event, caused huge interference with rather small scale electronic equipment. Such events must have happened several times in the past, too, with humans surviving.But only in recent years have we become entirely dependent on electronic equipment. The truth is we would suffer greatly if we underestimate the dangers of a possible Carrington or even more powerful event. Even though this would not wipe out humanity instantly, it would represent an immense challenge. There would be no electricity, heating, air conditioning, GPS or internet – food and medicines would go bad.2. Asteroid impactWe are now well aware of the dangers asteroids could pose to humanity – they are, after all, thought to have contributed to the extinction of the dinosaurs. Recent research has made us aware of the large host of space rocks in our solar system that could pose danger. We are at the starting point of envisaging and developing systems for protecting us against some of the smaller asteroids that could strike us. But against the bigger and rarer ones we are quite helpless. While they would not always destroy Earth or even make it uninhabitable, they could wipe out humanity by causing enormous tsunamis, fires and other natural disasters.3. Expanding sunWhere the previous cosmic dangers occur at the roll of a dice with a given probability, we know for certain that our sun will end its life in 7.72 billion years. At this point, it will throw off its outer atmosphere to form a planetary nebula, ending up as a stellar remnant know as a “white dwarf”.But humanity will not experience these final stages. As the sun becomes older, it will become cooler and larger. By the time it becomes a stellar giant it will be big enough to engulf both Mercury and Venus. Earth might seem safe at this point, but the sun will also create an extremely strong solar wind that will slow down the Earth. As a result, in about 7.59 billion years, our planet will spiral into the outer layers of the hugely expanded dying star and melt away forever.4. Local gamma ray burstExtremely powerful outbursts of energy called gamma ray bursts can be caused by binary star systems (two stars orbiting a common centre) and supernovas (exploding stars). These energy bursts are extremely powerful because they focus their energy into a narrow beam lasting no longer than seconds or minutes. The resulting radiation from one could damage and destroy our ozone layer, leaving life vulnerable to the sun’s harsh UV radiation.Astronomers have discovered a star system – WR 104 – that could host such an event. WR 104 is about 5,200-7,500 light years away, which is not far enough to be safe. And we can only guess when the burst will happen. Luckily, there is the possibility that the beam could miss us entirely when it does.5. Nearby supernovasSupernova explosions, which take place when a star has reached the end of its life, occur on average once or twice every 100 years in our Milky Way. They are more likely to occur closer to the dense centre of the Milky Way and we are about two-thirds of the way from the middle – not too bad. So can we expect a nearby supernova anytime soon? The star Betelgeuse – a red super giant nearing the end of its life – in the constellation of Orion is just 460-650 light years away. It could become a supernova now or in the next million years. Luckily, astronomers have estimated that a supernova would need to be within at least 50 light years of us for its radiation to damage our ozone layer. So it seems this particular star shouldn’t be too much of a concern.6. Moving starsMeanwhile, a wandering star on its path through the Milky Way might come so close to our sun that it would interact with the rocky “Oort cloud” at the edge of the solar system, which is the source of our comets. This might lead to an increased chance of a huge comet hurtling to Earth. Another roll of the dice.The sun itself follows a path through the Milky Way that takes us through more or less dense patches of interstellar gas. Currently we are within a less dense bubble created by a supernova. The sun’s wind and solar magnetic field help create a bubble-like region surrounding our solar system – the heliosphere – which shields us from interacting with the interstellar medium. When we leave this region in 20,000 to 50,000 years (depending on current observations and models), our heliosphere could be less effective, exposing Earth. We would possibly encounter increased climate change making life more challenging for humanity – if not impossible.And life goes on…The end of humanity on Earth is a given. But this is not something to make us crawl under a table. It is something that we cannot change, similar to our lives having a definite start and end. This is what defines us and makes us realise that the only thing we can do is make the most of our time on Earth. Especially when we know that Earth needs a careful balance to sustain humanity.All the above scenarios harbour possible destruction, but in every instance they also offer beauty and wonder. In many cases, they produce what allowed us to be created. So rather than looking into the night sky and wondering what will kill us next, we should marvel at the depth of space, the wonders therein and the sublime nature of the universe. Be inspired by space. It offers future and meaning.Source: The Conversation
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Cosmology & The Universe
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Their sum is both a new vision of the universe and a view of the universe as it once appeared new.“That was always out there,” said Jane Rigby, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Md., and the telescope’s operations manager. “We just had to build a telescope to go see what was there.”The Webb telescope — NASA’s vaunted successor to the Hubble Space Telescope, 30 years and nearly $10 billion in the making — is equipped to access this realm of cosmic history, study the first stars and galaxies and look for nearer, potentially habitable worlds. It is a collaboration among NASA, the European Space Agency, and the Canadian Space Agency.“We’re looking for the first things to come out of the Big Bang,” said John Mather, senior project scientist for the telescope.President Biden offered a preview Monday afternoon when he introduced what NASA officials and astronomers hailed as the deepest image yet taken of the cosmos, a mark that will probably be passed before the week is done as more data spews forth from NASA’s computers.The image, of a distant star cluster called SMACS 0723, revealed the presence of still more-distant galaxies spilled across the sky. The light from those galaxies, magnified into visibility by the gravitational field of the cluster, came from galaxies that existed more than 13 billion years ago.To look outward into space is to peer into the past. Light travels at a constant 186,000 miles per second, or close to 6 trillion miles per year, through the vacuum of space. To observe a star 10 light-years away is to see it as it existed 10 years ago, when the light left its surface. The farther away a star or galaxy lies, the older it is, making every telescope a kind of time machine.Astronomers theorize that the most distant, early stars may be unlike the stars we see today. The first stars were composed of pure hydrogen and helium left over from the Big Bang, and they could grow far more massive than the sun — then collapse quickly and violently into supermassive black holes of the kind that now populate the centers of most galaxies.The new pictures were rolled out during an hourlong ceremony at the Goddard Space Flight Center that was hosted by Michelle Thaller, the center’s assistant director for science communication, with video stops around the world. A few miles away at the Space Telescope Science Institute in Baltimore, an overflow crowd of astronomers whooped and hollered, oohed and aahed, as new images flashed on the screen — evidence that their telescope was working even better than hoped.One infrared skyscape showed Stephan’s Quintet, five galaxies packed improbably tightly in the constellation Pegasus. Four appear to be so close together that they may eventually merge. Indeed, the image revealed a band of dust that was being heated up as two of the galaxies ripped stars from each other.A view of the Southern Ring nebula, the remains of an exploded star, revealed hints of complex carbon molecules known as polycyclic aromatic hydrocarbons, or PAHs, floating in the midst. Such molecules drift through space, settling in clouds that then give birth to new stars, planets, asteroids — and whatever life might subsequently sprout.“Possibly, the formation of PAHs in these stars is a very important part of how life got started,” said Bruce Balick, an emeritus professor of astronomy at the University of Washington. “I’m gobsmacked.”The most striking image was of the Carina nebula, a vast, swirling cloud of dust that is both a star nursery and home to some of the most luminous and explosive stars in the Milky Way. Seen in infrared, the nebula resembled a looming, eroded coastal cliff dotted with hundreds of stars that astronomers had never seen before.“It took me a while to figure out what to call out in this image,” said Amber Straughn, deputy project scientist for the telescope, as she pointed to a craggy structure.Straughn added that she could not help thinking about the scale of the nebula, full of stars with planets of their own.“We humans really are connected to the universe,” she said. “We’re made out of the same stuff in this landscape.”From astronomers and at watch parties around the world, there was uniform relief and praise.“This event blew me away,” said Alan Dressler, an astronomer at the Carnegie Observatory who was instrumental in planning for the telescope 30 years ago. “Guess I’m not as jaded as I thought.”He added, “The growth in our understanding of the universe will be as great as it was with the Hubble, and that is really saying something. We’re in for a great adventure.”In an e-mail, Sara Seager, a planetary scientist at the Massachusetts Institute of Technology, said: “When I read (last week?) that people cried when they first saw the images I thought that was ridiculous. Now I feel like crying.”
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Cosmology & The Universe
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On July 12, NASA released the Webb telescope’s first images. Now, the space agency has translated the data from those images into sounds, allowing us to hear the cosmic wonders the telescope saw.OffEnglishWebb images in the near-infrared and mid-infrared, which encompass wavelengths human eyes are not capable of seeing. The telescope’s images are themselves translated from raw data into light we can see, a process detailed here. The sonified images go a step further, by taking those infrared wavelengths and mapping them to pitches of sound. They depict the Cosmic Cliffs of the Carina Nebula, the Southern Ring Nebula (in both near-infrared and mid-infrared), and the spectra of the exoplanet WASP-96b’s atmosphere, which indicated the presence of water.These sonifications, as they’re called, translate the data from different sources in the image into different sounds. In the case of the Carina Nebula image, which depicts vast columns of gas and dust and young stars, brighter light was made louder than fainter sources. The lower in the image the light source was, the lower the assigned frequency of the sound was.The Webb telescope launched in December 2021, and reached its observation point in space—about one million miles from Earth—a month later. The telescope then underwent months of commissioning its instruments and aligning its mirrors, but now it is fully operational and taking remarkably sharp images of some of the faintest and earliest light sources in the universe.“These compositions provide a different way to experience the detailed information in Webb’s first data,” said Quyen Hart, a senior education and outreach scientist at the Space Telescope Science Institute, in a NASA release.G/O Media may get a commission“Similar to how written descriptions are unique translations of visual images, sonifications also translate the visual images by encoding information, like color, brightness, star locations, or water absorption signatures, as sounds,” Hart added.The Southern Ring Nebula’s sound was two-fold. The nebula was imaged in both near-infrared and mid-infrared light, which highlights different features of the supernova remnant. If you listen closely, you’ll hear that the translated sound from the mid-infrared image is lower, corresponding to the fact that mid-infrared light has longer wavelengths than near-infrared light. On the whole, the Southern Ring audio is a little spookier than the Carina Nebula sound.The exoplanet spectra—which is a graph of data points representing components of the gas giant’s atmosphere—sounds a bit like the long slides used in cartoons to indicate a falling anvil. The NASA team added ploinks to indicate points in the data that bore the signature of H20–water in the planet’s atmosphere.The musical makeover of the Webb images comes on the heels of NASA’s sonification of the black hole at the center of the Perseus galaxy cluster. That sound, you’ll find, is a lot more ominous than the whimsical and ethereal vibes of the Webb soundscapes.The Perseus audio was also transposed up dozens of octaves—the actual sound of ripples in the gas surrounding the Perseus black hole is about 57 octaves below middle C, which is about 262 Hz.As the Webb telescope observes new targets, from dazzling deep fields to specific star clusters, we should expect more of these sonified images. They’re another way to experience the cosmos, and one that’s (for the most part) easy on the ears.More: Hear the Sound of a Black Hole ‘Echo’
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Cosmology & The Universe
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In a former gold mine a mile underground, inside a titanium tank filled with a rare liquified gas, scientists have begun the search for what so far has been unfindable: dark matter.Scientists are pretty sure the invisible stuff makes up most of the universe’s mass and say we wouldn’t be here without it – but they don’t know what it is. The race to solve this enormous mystery has brought one team to the depths under Lead, South Dakota.The question for scientists is basic, said Kevin Lesko, a physicist at Lawrence Berkeley National Laboratory. “What is this great place I live in? Right now, 95% of it is a mystery.”The idea is that a mile of dirt and rock, a giant tank, a second tank and the purest titanium in the world will block nearly all the cosmic rays and particles that zip around and through all of us every day. But dark matter particles, scientists think, can avoid all those obstacles. They hope one will fly into the vat of liquid xenon in the inner tank and smash into a xenon nucleus like two balls in a game of pool, revealing its existence in a flash of light seen by a device called “the time projection chamber”.Scientists announced Thursday that the five-year, $60m search finally got underway two months ago after a delay caused by the pandemic. So far the device has found ... nothing. At least no dark matter.Scientists hope that a particle of dark matter will fly into a vat of liquid xenon and smash into a nucleus to prove its existence. Photograph: Matthew Kapust/APThat’s OK, they say. The equipment appears to be working to filter out most of the background radiation they hoped to block. “To search for this very rare type of interaction, job number one is to first get rid of all of the ordinary sources of radiation, which would overwhelm the experiment,” said University of Maryland physicist Carter Hall.And if all their calculations and theories are right, they figure they’ll see only a couple fleeting signs of dark matter a year. The team of 250 scientists estimates they’ll get 20 times more data over the next couple of years.By the time the experiment finishes, the chance of finding dark matter with this device is “probably less than 50% but more than 10%”, said Hugh Lippincott, a physicist and spokesman for the experiment in a Thursday news conference.While that’s far from a sure thing, “you need a little enthusiasm”, Lesko said. “You don’t go into rare search physics without some hope of finding something.”Lab workers take care to avoid contaminating the dark matter detector in the Sanford Underground Research Facility in Lead, South Dakota. Photograph: Stephen Groves/APTwo hulking Depression-era hoists run an elevator that brings scientists to what’s called the Lux-Zeplin experiment in the Sanford Underground Research Facility. A 10-minute descent ends in a tunnel with cool-to-the-touch walls lined with netting. But the old, musty mine soon leads to a high-tech lab where dirt and contamination is the enemy. Helmets are exchanged for new cleaner ones and a double layer of baby blue booties go over steel-toed safety boots.The heart of the experiment is the giant tank called the cryostat, lead engineer Jeff Cherwinka said in a December 2019 tour before the device was closed and filled. He described it as “like a Thermos” made of “perhaps the purest titanium in the world” designed to keep the liquid xenon cold and keep background radiation at a minimum.Xenon is special, explained experiment physics coordinator Aaron Manalaysay, because it allows researchers to see if a collision is with one of its electrons or with its nucleus. If something hits the nucleus, it is more likely to be the dark matter that everyone is looking for, he said.These scientists tried a similar, smaller experiment here years ago. After coming up empty, they figured they had to go much bigger. Another large-scale experiment is underway in Italy run by a rival team, but no results have been announced so far.The scientists are trying to understand why the universe is not what it seems.The research team stands next to the giant tank called the cryostat, which one scientist likened to a Thermos. Photograph: Matthew Kapust/APOne part of the mystery is dark matter, which has by far most of the mass in the cosmos. Astronomers know it’s there because when they measure the stars and other regular matter in galaxies, they find that there is not nearly enough gravity to hold these clusters together. If nothing else was out there, galaxies would be “quickly flying apart”, Manalaysay said.“It is essentially impossible to understand our observation of history, of the evolutionary cosmos without dark matter,” Manalaysay said.Lippincott, a University of California, Santa Barbara, physicist, said, “We would not be here without dark matter.”So while there’s little doubt that dark matter exists, there’s lots of doubt about what it is. The leading theory is that it involves things called Wimps – weakly interacting massive particles.If that’s the case, Lux-Zeplin could be able to detect them. We want to find “where the wimps can be hiding”, Lippincott said.
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Cosmology & The Universe
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First light: an image of the “southern ring” nebula was released today as part of five first images from the James Webb Space Telescope. Left is from the NIRCam instrument while right is using the the MIRI instrument (Courtesy: NASA, ESA, CSA, and STScI) The first tranche of images and data from the $10bn James Webb Space Telescope (JWST) has been released today by NASA and partners. The four spectacular pictures – showing nebulae, a galaxy constellation as well as the atmospheric spectra of an exoplanet – follows the unveiling of the JWST’s first “deep field” image yesterday.
The JWST was launched on 25 December 2021 and a month later it had completed most of the delicate procedures to unfold and unpack the telescope. In February, the JWST released the first unaligned picture followed in late April by the first aligned images.
“Every image is a new discovery and it will give humanity a view of the universe that we have never seen before,” said NASA administrator Bill Nelson at an event today at NASA’s Goddard Space Flight Center. “These images show us light that is 13.5 billion years old. That is the threshold we are now crossing.”
Yesterday US president Joe Biden unveiled the first spectacular full-colour science image. Known as “SMACS 0723”, it is the telescope’s first “deep field” picture and shows how massive foreground galaxy clusters magnify and distort the light of objects behind them, allowing a deep-field view into extremely distant and faint galaxy populations.
Today, four further images have been unveiled. They are an image of the Southern Ring, or “eight-burst” nebula (main image), which is a planetary nebula almost a half a light-year in diameter and is located approximately 2000 light years away from Earth.
NASA has also released the atmospheric spectra of the WASP-96b exoplanet, which was first announced in 2014. Composed mainly of gas, the planet is located nearly 1150 light-years from Earth and orbits its star every 3.4 days.
Atmospheric composition of the WASP-96b exoplanet. (Courtesy: NASA, ESA, CSA, and STScI)
Another object that has been pictured isStephan’s Quintet in the constellation Pegasus. It is about 290 million light-years away is and is the first compact galaxy group ever discovered where four of the five galaxies within the quintet often have close encounters.
Stephan’s Quintet. (Courtesy: NASA, ESA, CSA, and STScI)
Last but not least, the Carina Nebula, which is one of the largest and brightest nebulae in the sky and is located about 7600 light-years away in the southern constellation Carina.
“We have an observatory that is excellent shape,” JWST project manager Bill Ochs from the Goddard Space Flight Center noted. “When I look at these images I see dedication, personal sacrifice, passion and finally the faces of all the individuals who have worked on this mission.”
The JWST is a collaboration between NASA, the European Space Agency and the Canadian Space Agency. It is expected that the JWST will continue observations for at least two decades.
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Cosmology & The Universe
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Despite a primary diet of gas and dust, black holes will consume anything that comes too close — meaning moons, planets and even stars are on the cosmic menu. But does this mean black holes greedily suck in everything around them, like cosmic vacuum cleaners, as commonly imagined?
The answer is no. To feed and grow, black holes actually need a little luck, and a big, bright disk of matter around them.
"Often we think of black holes as sucking matter in, like a vacuum cleaner. But that isn't a great way to think about black holes," John Regan, a Royal Society University research fellow at Maynooth University who specializes in black holes, told Live Science.
"In terms of the size of the galaxy around it, the black hole is tiny," Regan said. "So, in fact, especially for small black holes, you're nearly better off thinking of them like feathers in the wind."
This analogy points to the fact that black holes can drift through galaxies, with a very lucky few eventually finding themselves in dense environments rich with gas and dust where they can start gathering mass. It's "very unlikely" for a small black hole to end up in such an environment, Regan added, with most black holes winding up in regions of space with little or no gas to feed on.
So rather than inexorably pulling mass toward them from great distances, black holes depend on being in a region with plenty of food to begin with. Even then, however, lucky black holes rely on an external delivery mechanism to bring them matter.
How do black holes feed?
When surrounded by gas and dust, black holes don't just immediately start drawing everything toward them and consuming it. Instead, this matter forms a flattened, fast-moving structure called an accretion disk around the black hole.
Black holes grow when rapidly spinning disk material gradually moves from the disk's outer edge to the inner edge closest to the black hole. From there, it is gradually "fed" to the black hole's event horizon — the point beyond which nothing, not even light, can escape the hole's gargantuan gravitational influence.
Matter within the accretion disk is violently heated by immense tidal forces, causing many accretion disks to glow brightly. This makes detecting accretion disks one of the easiest ways for astronomers to locate black holes.
Black holes can also swallow stars, but only the most massive objects can swallow a star whole, according to Hubblesite. More often, when a black hole feeds on a star, it stretches and squashes it with tidal forces first, in a process called spaghettification or a tidal disruption event (TDE).
"A TDE is basically what happens when a star wanders too close to a supermassive black hole and gets torn apart by the tidal forces surrounding that black hole," Yvette Cendes, a radio astronomer at the Harvard & Smithsonian Center for Astrophysics, told Live Science. "The unbinding of the star is actually very fast. That process is like a few hours, tops."
Traditional models of TDEs suggest that half of this spaghettified stellar material gets flung outward, away from the black hole, Cendes added. The other half forms an accretion disk — or joins an existing one — with the destructive black hole at its center. The stellar material is further broken apart by the violent conditions in the accretion disk and is also gradually fed to the event horizon.
Black hole 'vampires'?
Black holes don't always destroy the stars they feed on, however. Even though they don't suck anything up, black holes can act like cosmic vampires in another way: If a black hole is in a binary system with a star, its gravity can pull stellar material from the star's outer layers, keeping its stellar victim alive while gradually feeding on it. This process hastens the demise of the victim star, which itself could leave behind a second black hole in the system when it eventually dies.
An example of such a system is Cygnus X-1, in which a blue supergiant star with a mass around 25 times that of the sun orbits a compact object with a mass 8 to 10 times that of the sun — believed to be a stellar-mass black hole (the smallest type of black hole that astronomers have observed). This suspected black hole is strongly emitting X-rays from around it, likely because stellar material is being stripped from the star and falling to the event horizon via an accretion disk.
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Robert Lea is a science journalist in the U.K. who specializes in science, space, physics, astronomy, astrophysics, cosmology, quantum mechanics and technology. Rob's articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University
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Cosmology & The Universe
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Artist's illustration of a small Saturn-like planet discovered in the system LkCa 15. The planet resides within dense rings of dust and gas that surround a bright yellow star. Material accumulates in a clump and arc-shape, about 60 degrees away from the planet. Note: This illustration is not to scale. Credit: M.Weiss/Center for Astrophysics | Harvard & Smithsonian Astronomers agree that planets are born in protoplanetary disks—rings of dust and gas that surround young, newborn stars. While hundreds of these disks have been spotted throughout the universe, observations of actual planetary birth and formation have proved difficult within these environments. Now, astronomers at the Center for Astrophysics | Harvard & Smithsonian have developed a new way to detect these elusive newborn planets—and with it, "smoking gun" evidence of a small Neptune or Saturn-like planet lurking in a disk. The results are described today in The Astrophysical Journal Letters. "Directly detecting young planets is very challenging and has so far only been successful in one or two cases," says Feng Long, a postdoctoral fellow at the Center for Astrophysics who led the new study. "The planets are always too faint for us to see because they're embedded in thick layers of gas and dust."
Scientists instead must hunt for clues to infer a planet is developing beneath the dust. "In the past few years, we've seen many structures pop up on disks that we think are caused by a planet's presence, but it could be caused by something else, too," Long says. "We need new techniques to look at and support that a planet is there."
For her study, Long decided to re-examine a protoplanetary disk known as LkCa 15. Located 518 light years away, the disk sits in the Taurus constellation on the sky. Scientists previously reported evidence for planet formation in the disk using observations with the ALMA Observatory.
Long dove into new high-resolution ALMA data on LkCa 15, obtained primarily in 2019, and discovered two faint features that had not previously been detected.
About 42 astronomical units out from the star—or 42 times the distance Earth is from the Sun—Long discovered a dusty ring with two separate and bright bunches of material orbiting within it. The material took the shape of a small clump and a larger arc, and were separated by 120 degrees. Long examined the scenario with computer models to figure out what was causing the buildup of material and learned that their size and locations matched the model for the presence of a planet. "This arc and clump are separated by about 120 degrees," she says. "That degree of separation doesn't just happen—it's important mathematically."
Long points to positions in space known as Lagrange points, where two bodies in motion—such as a star and orbiting planet—produce enhanced regions of attraction around them where matter may accumulate. "We're seeing that this material is not just floating around freely, it's stable and has a preference where it wants to be located based on physics and the objects involved," Long explains. In this case, the arc and clump of material Long detected are located at the L4 and L5 Lagrange points. Hidden 60 degrees between them is a small planet causing the accumulation of dust at points L4 and L5.
The results show the planet is roughly the size of Neptune or Saturn, and around one to three million years old. (That's relatively young when it comes to planets.) Directly imaging the small, newborn planet may not be possible any time soon due to technology constraints, but Long believes further ALMA observations of LkCa 15 can provide additional evidence supporting her planetary discovery. She also hopes her new approach for detecting planets—with material preferentially accumulating at Lagrange points—will be utilized in the future by astronomers. "I do hope this method can be widely adopted in the future," she says. "The only caveat is that this requires very deep data as the signal is weak." More information: Feng Long et al, ALMA Detection of Dust Trapping around Lagrangian Points in the LkCa 15 Disk, The Astrophysical Journal Letters (2022). DOI: 10.3847/2041-8213/ac8b10 Citation: It's a planet: New evidence of baby planet in the making (2022, September 14) retrieved 14 September 2022 from https://phys.org/news/2022-09-planet-evidence-baby.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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Cosmology & The Universe
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By Matt WilliamsUnderstanding how the Universe came to be is one of the greater challenges of being an astrophysicist. Given the observable Universe’s sheer size (46.6 billion light years) and staggering age (13.8 billion years), this is no easy task. Nevertheless, ongoing observations, calculations and computer simulations have allowed astrophysicists to learn a great deal about how galaxies and larger structures have changed over time. For example, a recent study by a team from the University of Kentucky (UK) has challenged previously-held notions about how our galaxy has evolved to become what we see today. Based on observations made of the Milky Way’s stellar disk, which was previously thought to be smooth, the team found evidence of asymmetric ripples. This indicates that in the past, our galaxy may have be shaped by ancient impacts.The study, titled “Milky Way Tomography with K and M Dwarf Stars: The Vertical Structure of the Galactic Disk“, recently appeared in the The Astrophysical Journal. Led by Deborah Ferguson, a 2016 UK graduate, the team consisted of Professor Susan Gardner – from the UK College of Arts and Sciences – and Brian Yanny, an astrophysicist from the Fermilab Center for Particle Astrophysics (FCPA).This study evolved from Ferguson’s senior thesis, which was overseen by Prof. Gardner. At the time, Ferguson sought to expand on previous research by Gardner and Yanny, which also sought to understand the presence of ripples in our galaxy’s stellar disk. For the sake of this new study, the team relied on data obtained by the Sloan Digital Sky Survey‘s (SDSS) 2.5m Telescope, located at the Apache Point Observatory in New Mexico. This allowed the team to examine the spatial distribution of 3.6 million stars in the Milky Way Galaxy, from which they confirmed the presence of asymmetric ripples. These, they claim, can be interpreted as evidence of the Milky Way’s ancient impacts – in other words, that these ripples resulted from our galaxy coming into contact with other galaxies in the past.These could include a merger between the Milky Way and the Sagittarius dwarf galaxy roughly 0.85 billion years ago, as well as our galaxy’s current merger with the Canis Major dwarf galaxy. As Prof. Gardner explained in a recent UK press release:“These impacts are thought to have been the ‘architects’ of the Milky Way’s central bar and spiral arms. Just as the ripples on the surface of a smooth lake suggest the passing of a distant speed boat, we search for departures from the symmetries we would expect in the distributions of the stars to find evidence of ancient impacts. We have found extensive evidence for the breaking of all these symmetries and thus build the case for the role of ancient impacts in forming the structure of our Milky Way.”As noted, Gardner’s previous work also indicated that when it came to north/south symmetry of stars in the Milky Way’s disk, there was a vertical “ripple”. In other words, the number of stars that lay above or below the stellar disk would increase from one sampling to the next the farther they looked from the center of the galactic disk. But thanks to the most recent data obtained by the SDSS, the team had a much larger sample to base their conclusions on.And ultimately, these findings confirmed the observations made by Ferguson and Lally, and also turned up evidence of an asymmetry in the plane of the galactic disk as well. As Ferguson explained:“Having access to millions of stars from the SDSS allowed us to study galactic structure in an entirely new way by breaking the sky up into smaller regions without loss of statistics. It has been incredible watching this project evolve and the results emerge as we plotted the stellar densities and saw intriguing patterns across the footprint. As more studies are being done in this field, I am excited to see what we can learn about the structure of our galaxy and the forces that helped to shape it.”Understanding how our galaxy evolved and what role ancient impact played is essential to understanding the history and evolution of the Universe as a whole. And in addition to helping us confirm (or update) our current cosmological models, studies like this one can also tell us much about what lies in store for our galaxy billions of years from now.For decades, astronomers have been of the opinion that in roughly 4 billion years, the Milky Way will collide with Andromeda. This event is likely to have tremendous repercussions, leading to the merger of both galaxy’s supermassive black holes, stellar collisions, and stars being ejected. While it’s doubtful humanity will be around for this event, it would still be worthwhile to know how this process will shape our galaxy and the local Universe.Source: Universe Today - Further Reading: University of Kentucky, The Astrophysical Journal
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Cosmology & The Universe
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The "deepest and sharpest infrared image of the distant universe to date" has been revealed. The picture was made public by NASA and is the first to be taken by the world's most advanced telescope, the James Webb Space Telescope (JWST).
"We're looking back more than 13 billion years... and we're going further... this is just the first image and since we know the universe is 13.8 billion years old, we're going back almost to the beginning," NASA administrator Bill Nelson said."It is going to be so precise you are going to see whether or not planets are habitable. And when you look at something as big as this we're going to be able to answer questions that we don't even know what the questions are yet."The picture released last night shows a galaxy cluster called SMACS 0723 and is the first of several to be revealed over the next few days. It is the farthest humanity has ever seen in both time and distance, closer to the dawn of time and the edge of the universe, with part of the image showing light from soon after the Big Bang.
JWST isn't just an upgrade on the 32-year-old Hubble Space Telescope. It's an entirely new way of looking at the universe. More on Nasa A dying star and a 'cosmic dance': Ancient galaxies revealed in never-seen-before telescope pictures James Webb Telescope live updates: NASA reveals images that tell secrets of universe The Hubble Space Telescope: What are its greatest hits? The light-gathering ability of the telescope - the best measure of its power to "see" things - is more than twice that of Hubble. What's more, the £8.4bn ($10bn) machine is designed to see objects using infrared light.Though it's invisible to the human eye, infrared is the colour of the oldest and faintest objects in the universe.Scientists and engineers from three space agencies - NASA, the European Space Agency and the Canadian Space Agency - worked for 20 years to complete the telescope. Image: The picture was unveiled during a special event at the White House. Pic: AP Along the way, several moves were made to cancel the mission as costs and deadlines were exceeded.The first major challenge for JWST's designers was to get a telescope bigger than two double-decker buses side by side into space in the first place.That required Webb to be folded in on itself, origami-style. Its massive 6.5m polished gold mirror was even made so it folded down into three segments.To the surprise of even some of those who built it, JWST unpacked itself flawlessly once safely in orbit in January - with each segment of its mirror now perfectly aligned.The next challenge was ensuring Webb was cold enough to "see" infrared light - any warm object produces it.Read more:Astronaut returns after 355 days in spaceNASA releases audio recording of a black holePicture of Mars 'doorway' spawns conspiracy theories Is this a big deal? Tom Clarke Science and technology editor @aTomClarke To those of us who aren't astronomers, it's hard to see what the big deal is. An image of points of light, coloured blobs and spirals of galaxies of the kind we're familiar with. But in fact, this image is something very different indeed. Read Tom's full analysis here. Though space is cold, one glimpse of the Sun's rays or stray waste heat from its own systems would blind the telescope's infrared vision much like the headlights of an oncoming car at night.JWST's instruments are cooled to -267C. To shield it from the sun, the telescope orbits the Earth on the other side of the moon, cloaked in its shadow. Please use Chrome browser for a more accessible video player World's most powerful telescope launched Its instruments are also protected from and stray heat by five layers of tennis court-size sun shade that also unfurled once the telescope was in orbit.While scientifically important in its own right, this image - and those that will follow later today - are very much a first glimpse. They were chosen to showcase JWST's capabilities to an entire generation of scientists that will use the orbiting observatory - and also to the public that paid for it.Many breakthroughs in astronomy and astrophysics come after multiple observations of distant objects over months or years.This is particularly true when studying distant worlds in other solar systems. But can we really expect a 13.8 billion-year-old universe to give up its secrets quickly?
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Cosmology & The Universe
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A new paper, published in AIP Advances, examines the scientific implications of the new law on a number of other physical systems and environments, including biological, atomic physics, and cosmology. Key findings include:
- Biological systems: The second law of infodynamics challenges the conventional understanding of genetic mutations, suggesting that they follow a pattern governed by information entropy. This discovery has profound implications for fields such as genetic research, evolutionary biology, genetic therapies, pharmacology, virology, and pandemic monitoring.
- Atomic physics: The paper explains the behavior of electrons in multi-electron atoms, providing insights into phenomena like Hund's rule; which states that the term with maximum multiplicity lies lowest in energy. Electrons arrange themselves in a way that minimizes their information entropy, shedding light on atomic physics and stability of chemicals.
- Cosmology: The second law of infodynamics is shown to be a cosmological necessity, with thermodynamic considerations applied to an adiabatically expanding universe supporting its validity. "The paper also provides an explanation for the prevalence of symmetry in the universe," added Dr. Vopson. "Symmetry principles play an important role with respect to the laws of nature, but until now there has been little explanation as to why that could be. My findings demonstrate that high symmetry corresponds to the lowest information entropy state, potentially explaining nature's inclination towards it."
"This approach, where excess information is removed, resembles the process of a computer deleting or compressing waste code to save storage space and optimize power consumption. And as a result supports the idea that we're living in a simulation."
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Cosmology & The Universe
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Galaxy clusters yield new evidence for standard model of cosmology
Cosmologists have found new evidence for the standard model of cosmology—this time, using data on the structure of galaxy clusters.
In a recent study published in Monthly Notices of the Royal Astronomical Society, a team led by physicists at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University made detailed measurements of the X-ray emission from galaxy clusters, which revealed the distribution of matter within them. In turn, the data helped the scientists test the prevailing theory of the structure and evolution of the universe, known as Lambda-CDM.
Getting there wasn't an easy task, however.
Here's the trouble: Inferring the mass distributions of galaxy clusters from their X-ray emission is most reliable when the energy in the gas within clusters is balanced by the pull of gravity, which holds the whole system together. Measurements of the mass distributions in real clusters therefore focus on those that have settled down to a "relaxed" state. When comparing to theoretical predictions, it is therefore essential to take this selection of relaxed clusters into account.
Keeping this in mind, Stanford physics graduate student Elise Darragh-Ford and her colleagues examined computer-simulated clusters produced by the The Three Hundred Project. First, they computed what the X-ray emission for each simulated cluster should look like. Then, they applied the same observational criteria used to identify relaxed galaxy clusters from real data to the simulated images to winnow the set down.
The researchers next measured the relationships among three properties—the cluster mass, how centrally concentrated this mass was, and the redshift of the clusters, which reflects how old the universe was when the light we observe was emitted—for both the simulated Three Hundred Project clusters and 44 real clusters observed with NASA's Chandra X-ray Observatory.
The team found consistent results from both data sets: Overall, clusters have become more centrally concentrated over time, while at any given time, less massive clusters are more centrally concentrated than more massive ones. "The measured relationships agree extremely well between observation and theory, providing strong support for the Lambda-CDM paradigm," said Darragh-Ford.
In the future, the scientists hope to be able to expand the size of both the observed and simulated galaxy cluster data sets in their analysis. SLAC-supported projects coming online in the next few years, including the Rubin Observatory's Legacy Survey of Space and Time and the fourth-generation cosmic microwave background experiment (CMB-S4), will help identify a much larger number of galaxy clusters, while planned space missions, such as the European Space Agency's ATHENA satellite, can follow up with X-ray measurements. SLAC cosmologists are also working to expand the size and accuracy of computer simulations of the cosmos, making it possible to study galaxy clusters in greater detail and place stringent limits on alternative cosmological scenarios.
More information: Elise Darragh-Ford et al, The Concentration–Mass relation of massive, dynamically relaxed galaxy clusters: agreement between observations and ΛCDM simulations, Monthly Notices of the Royal Astronomical Society (2023). DOI: 10.1093/mnras/stad585
Journal information: Monthly Notices of the Royal Astronomical Society
Provided by SLAC National Accelerator Laboratory
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Cosmology & The Universe
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Introduction
Like a bright city in the middle of a barren desert, our galactic neighborhood is enveloped by a cosmic void — an enormous, almost unfathomably empty pocket of space. Recently, sky surveys have spotted thousands more of these vacant bubbles. Now, researchers have found a way to pull information out of these cosmic voids: By counting how many of them exist in a volume of space, scientists have devised a new way to explore two of the thorniest questions in cosmology.
“It’s the very first time that we have used void numbers to extract cosmological information,” said Alice Pisani, a cosmologist at Princeton University and the Flatiron Institute and an author of a new preprint describing the work. “If we want to push the boundaries of science, we need to go beyond what has already been done.”
Researchers have been looking for new tools in part because they have some big mysteries to solve. The first, and most perplexing, is the rate at which the universe expands, a value known as the Hubble constant. For more than a decade, scientists have struggled to reconcile conflicting measurements of this rate, with some even calling the issue the biggest crisis in cosmology.
In addition, researchers have conflicting measurements of the clumpiness of cosmic matter —the average density of large-scale structures, dark matter, galaxies, gas and voids distributed throughout the universe as a function of time.
Typically, astronomers measure those values in two complementary ways. Curiously, these two methods produce different values for both the Hubble constant and the so-called matter clustering strength.
In their new approach, Pisani and her colleagues use cosmic voids to estimate both values. And their early results, which seem to agree much more closely with one of the traditional methods than the other, are now contributing their own complexities to an already fraught disagreement.
Introduction
“The Hubble tension has lasted a decade so far because it is a hard problem,” said Adam Riess, an astronomer at Johns Hopkins University who uses supernovas to estimate the Hubble constant. “The obvious issues have been checked and the data has improved, so the dilemma deepens.”
Now, the hope is that studying nearly nothing could lead to something big.
Building Bubbles
Voids are regions of space that are less dense than the universe, on average. Their boundaries are defined by the immense sheets and filaments of galaxies that are woven throughout the cosmos. Some voids span hundreds of millions of light-years, and together, these bubbles make up at least 80% of the universe’s volume. For a long time, though, no one paid much attention to them. “I began my research in 2011 with around 200 voids,” Pisani said. “But now we have roughly 6,000.”
The bubbles have a tendency to expand because inside them, there isn’t much matter to exert an inward gravitational pull. The stuff outside them tends to stay away. And any galaxies that start inside a void get tugged outward by the gravitational pull of the structures defining a void’s edge. Because of this, in a void “very little happens,” Pisani said. “There are no mergers, no complicated astrophysics. This makes them very easy to deal with.”
But each void’s shape is different, which can make it tricky for scientists to identify them. “We want to make sure our voids are robust,” Pisani said. “How empty does it have to be, and how do I measure it?”
It turns out that the definition of “nothing” depends on the type of information astronomers want to extract. Pisani and colleagues started with a mathematical tool called a Voronoi diagram, which identifies the shapes that make up a 3D mosaic. These diagrams are typically used to study things like bubbles in foams and cells in biological tissues.
In the current work, Pisani and her colleagues tailored their Voronoi tessellations to identify about 6,000 voids in the data from an enormous galactic mapping project called the Baryon Oscillation Spectroscopic Survey (BOSS).
“Voids are complementary to the catalog of galaxies,” said Benjamin Wandelt, an astrophysicist at Sorbonne University in Paris who was not involved in the study. “They are a new way to probe cosmic structure.”
Once Pisani and colleagues had their map of voids, they set out to see what it could reveal about the expanding universe.
Something From Nothing
Every cosmic void is a window on a great cosmic conflict. On one side, there’s dark energy, the mysterious force that causes our universe to expand ever more quickly. Dark energy is present even in empty space, so it dominates the physics of the void. On the other side of the conflict there’s gravity, which attempts to pull the void together. And then matter’s clumpiness adds wrinkles to the voids.
Pisani and her colleagues, including Sofia Contarini of the University of Bologna, modeled how the expansion of the universe would affect the number of voids of different sizes. In their model, which kept a handful of other cosmological parameters constant, a slower expansion rate produced a higher density of smaller, more crumpled voids. On the other hand, if expansion was faster and matter didn’t clump as readily, they expected to find more large, smooth voids.
The group then compared their model predictions with observations from the BOSS survey. From this, they were able to estimate both clumpiness and the Hubble constant.
They then juxtaposed their measurements with the two traditional ways to measure these values. The first method uses a type of cosmic explosion called a Type Ia supernova. The second relies on the cosmic microwave background (CMB), the radiation left over from the Big Bang.
The void data revealed a Hubble constant that varied by less than 1% from the CMB’s estimate. The result for clumpiness was more muddled, but it also aligned more closely with the CMB than with Type Ia supernovas.
Perplexingly, the voids in the BOSS survey lie closer in space and time to more recent Type Ia supernovas — making it a bit surprising that the void measurements align more closely with the primordial CMB. Wandelt, though, suggested that the results might reveal a new understanding about the universe.
“There is one deep insight that makes my hair stand up,” he said. Inside voids, structures never formed and evolved, so voids “are time capsules of the early universe.”
In other words, if the physics of the early universe was different from the physics of the present day, the voids may have preserved it.
The Future of Absence
Others think it’s too soon to draw any conclusions from the new results.
Even with thousands of voids, the study’s error bars are still too large to say anything conclusive. “This analysis is extremely well done,” said Ruth Durrer, a theoretical physicist at the University of Geneva who did not take part in the research. But, Durrer noted, the results haven’t reached statistical significance — yet. “If Alice wants to be in the club of amazingly good Hubble constant measurements, she has to get to the 1% limit, which is a huge challenge,” Durrer said.
Pisani said she considers the work to be a proof of concept. It will likely take another decade — and the help of future missions such as NASA’s Nancy Grace Roman Space Telescope and SPHEREx Observatory — to accumulate enough void data to be on a par with the conflicting CMB and Type Ia supernova measurements.
Durrer also points out that maybe these arguments — the attempts to reconcile cosmic tensions — are all much ado about nothing, and that the observational disagreements could be pointing to a reality that scientists shouldn’t be trying to erase.
“The supernova and CMB groups are doing measurements that are very, very different,” she said. “So there may be new physics that explains why we shouldn’t be seeing the same thing.”
Editor’s note: Alice Pisani receives funding from the Simons Foundation, which also funds this editorially independent magazine. Simons Foundation funding decisions have no influence on our coverage. More details are available here.
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Cosmology & The Universe
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A collision between two ancient icy moons that may have once orbited Saturn could have given rise to the planet's iconic ring system, a new study reveals.
Saturn is probably the most eye-catching planet in the solar system, but it may also be one of the most mind-boggling. Surrounded by a series of seven concentric rings and orbited by an army of 245 moons, the gas giant, second in size only to Jupiter, has puzzled astronomers for centuries.
A new study may have found an answer to one of Saturn's mysteries — the origin of its rings. The study, based on dozens of computer simulations, used data collected by NASA's Cassini mission that orbited Saturn for 13 years between 2004 and 2017. The probe found the material that makes up the rings, first observed by Galileo Galilei in 1610, consists of icy fragments that are very pristine and unpolluted by dust. Those Cassini findings suggested that the iconic rings of Saturn must be fairly young, only a few million years old, and that for the majority of the solar system's 4.5 billion-year history, the iconic Saturn looked much more bland.
The researchers behind the new study, a team consisting of experts from NASA and Durham University in the U.K., speculated that the rings may have formed from a relatively recent collision of two ancient icy moons. They used powerful supercomputers to simulate nearly 200 scenarios of such a collision.
The results revealed that a collision between two moons about as large as Saturn's current moons Dione and Rhea (which have diameters equivalent to one third and a little under a half of Earth's moon diameter respectively), could explain the existence of those rings.
"We tested a hypothesis for the recent formation of Saturn’s rings and have found that an impact of icy moons is able to send enough material near to Saturn to form the rings that we see now," Vincent Eke, Associate Professor in the Department of Physics/Institute for Computational Cosmology at Durham University, said in a statement.
Although the rings are made almost purely from ice, scientists think that Saturn's icy moons have rocky cores. The simulations confirmed that the icy fragments and the rocky bits would scatter in different ways after a collision, allowing the rocks to coalesce into new moons while the ice would get dispersed in orbits closer to Saturn's surface.
Rings can only form around celestial bodies within the Roche limit, a boundary where the gravity of the orbiting material is weaker than the tidal forces of the body it orbits.
The simulations show that many of the hypothetical collisions would inject a lot of ice into lower altitudes while the rocks would clump together in higher orbits.
"This scenario naturally leads to ice-rich rings because when the progenitor moons smash into one another, the rock in the cores of the colliding bodies is dispersed less widely than the overlying ice," Eke said.
Saturn's ice-covered moons are of great interest to scientists as some of them, such as the tiny Enceladus, might harbor conditions suitable for the emergence of life. There is still a lot that scientists don't know about Saturn and its past, and the results of the study are only a small step toward cracking the planet's mysteries.
The study was published in The Astrophysical Journal on Sept. 27.
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Cosmology & The Universe
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NASA's James Webb Space Telescope (JWST) keeps spotting galaxies that are too big to exist, scientists have claimed.
Six of these star clusters are far too massive to be the age their data suggests they are, which is between 500 and 700 million years old.
This means that, unless the data has been analysed incorrectly, there is still something fundamental to learn about how galaxies formed after the Big Bang.
'If the masses are right, then we are in uncharted territory,' said the study's author, Dr Mike Boylan-Kolchin from the University of Texas at Austin.
One theory is that the universe expanded much more quickly after the Big Bang than is currently assumed.
The $10 billion JWST, which sent back its first official photos in July last year, is designed to detect light from the earliest stars and galaxies.
HOW DOES JWST SEE BACK IN TIME? The further away an object is, the further back in time we are looking. This is because of the time it takes light to travel from the object to us. With James Webb's larger mirror, it will be able to see almost the whole way back to the beginning of the Universe, around 13.7 billion years ago. With its ability to view the Universe in longer wavelength infrared light, James Webb will be capable of seeing some of the most distant galaxies in our Universe, certainly with more ease than than the visible/ultraviolet light view of Hubble. This is because light from distant objects is stretched out by the expansion of our Universe - an effect known as redshift - pushing the light out of the visible range and into infrared.
The further away an object is, the further back in time it is looking, because it takes longer for the light to reach its 21 foot-long (6 m) mirror.
It is the world's biggest and most powerful orbital space telescope, and is capable of peering back 100 to 200 million years after the Big Bang.
In February, scientists at the Swinburne University of Technology in Australia analysed the data it had collected on six galaxies.
They estimated the age of the first one they looked at to be about 13.8 billion years old, but the light JWST had detected had taken 13 billion years to reach it.
This meant that what they were observing was a picture of how it looked when the universe was just 700 million years old - barely 5 per cent of its current age.
However, this picture also showed it was made up of 100 billion stars - the same amount as the present-day Milky Way, which had 13 billion more years to grow.
It was a similar story for the five other galaxies, where they contained way more stars than would be predicted for a cluster of their age.
For a follow-up study, published in Nature Astronomy last week, Dr Boylan-Kolchin 'stress tested' these results against the 'ΛCDM cosmological model'.
This is a framework for understanding the role of dark energy (Λ) and cold dark matter (CDM) in shaping the universe's evolution.
The astronomy professor found that, in theory, galaxies of this size and age are possible with this model, but are at an 'absolute upper limit'.
In February, scientists analysed the data it had collected on six galaxies. They estimated the age of the first one they looked at to be about 13.8 billion years old, but the light JWST had detected had taken 13 billion years to reach it. This meant that what were observing was a picture of how it looked when the universe was just 700 million years old - barely 5 per cent of its current age. However, this picture also showed it was made up of 100 billion stars - the same amount as the present-day Milky Way, which had 13 billion more years to grow. Pictured: The six massive galaxies and their surroundings in the sky
Galaxies form when clouds of gas collapse under their own gravity, becoming increasingly dense and hot, and eventually forming stars.
But some of this gas can be lost, either because it is ejected during the star formation process, or stripped away by an exterior force, like a nearby supernova.
'We typically see a maximum of 10 per cent of gas converted into stars,' said Dr Boylan-Kolchin.
However, for these six galaxies to have grown as big as they have in the time they have existed, they must have been converting nearly 100 per cent of their available gas into stars.
Dr Boylan-Kolchin added: 'While 100 per cent conversion of gas into stars is technically right at the edge of what is theoretically possible, it's really the case that this would require something to be very different from what we expect.'
This means that the ΛCDM model, which has been relied upon by cosmologists since the late 1990s, may not be totally correct.
Dr Boylan-Kolchin said. 'We'll require something very new about galaxy formation or a modification to cosmology.
'One of the most extreme possibilities is that the universe was expanding faster shortly after the Big Bang than we predict, which might require new forces and particles.'
Therefore, it is possible that the model needs to be altered to take these new, faster galaxy formation processes into account.
It could also be the case that there was more matter available to the start of the universe for star and galaxy formation, which the model should also account for.
But before scientists jump to change their fundamental approach to cosmology, the data from the JWST needs to be confirmed as correct.
It may be the case that supermassive black holes could have heated up the gas surrounding the galaxies, making them appear larger than they are.
The light that the JWST detected may also not have originated as far back as 13 billion years, meaning that it may actually show the galaxies at more advanced ages.
As light travels across expanding space, its wavelength is stretched and frequency reduced, through what is known as 'redshift'.
The magnitude of the redshift allows scientists to calculate when the light was emitted from a star, but it can be impacted by dust and give the wrong age.
It is hoped further study will reveal if this is the case.
Dr Boylan-Kolchin wrote: 'If analysis of JWST data continues to reveal the presence of strikingly massive galaxies at very early cosmic epochs, more exciting surprises lie ahead for the fields of galaxy formation and cosmology.'
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Cosmology & The Universe
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The Moon is Earth’s constant companion. But as ubiquitous as Luna may seem, Earth hasn’t always had a moon.
Some 4.5 billion years ago, when the solar system was still forming, a wandering Mars-sized body named Theia slammed into a fledgling, moonless Earth. Traditionally, it is thought that this Theia-Earth collision spewed debris around our planet, which gradually coalesced to form the Moon. This theory for how the Moon formed is known as the Giant Impact Hypothesis.
But there are a few problems with the Giant Impact Hypothesis as it stands. The most glaring being the similarities between lunar rocks and Earth’s mantle. When the Apollo astronauts brought back samples from the Moon, scientists found that their isotopic signatures — chemical clues that point to where and how they were created — closely (but not perfectly) matched Earth. Thus, since no other body in the solar system so sharply resembles Earth’s rocks, it is likely that much of the material making up the Moon came from our planet.
But in the debris-disk scenario of the Giant Impact Hypothesis, it is material from Theia that constituted most of the debris that would eventually form the Moon. And alternative explanations often struggled to explain the Moon’s current orbit.
However, new simulations from scientists at Durham University’s Institute for Computational Cosmology point to a tweaked scenario in which the Moon formed immediately following the Theia collision. In fact, the simulations show the Moon might have formed in mere hours, which is far quicker than previously thought.
“This opens up a whole new range of possible starting places for the Moon’s evolution,” said lead author Jacob Kegerreis in a NASA press release. The paper was published Oct. 4 in the Astrophysical Journal Letters. A puzzle of planetary proportions The team modeled the Theia-Earth collision approximately 400 times, using smoothed particle hydrodynamics in their numerical simulations. This method, commonly deployed for simulations of giant impacts, enables scientists to model particles under the influence of both gravity and pressure. Previously, hundreds of thousands to millions of particles were used to simulate the formation of the Moon. But these new simulations utilized up to a hundred million particles, making them some of the most detailed yet. The extra computational power showed that, at lower-resolutions, researchers miss out on crucial behaviors that occur in such collisions. “We went into this project not knowing exactly what the outcomes of these high-resolution simulations would be,” said Kegerreis. “So, on top of the big eye-opener that standard resolutions can give you misleading answers, it was extra exciting that the new results could include a tantalizingly Moon-like satellite in orbit." In their direct-formation simulations, the team was able to produce a Moon with a wide orbit and an interior that isn’t completely molten. Together, these attributes could help explain the Moon’s tilted orbit and relatively thin crust. However intriguing, the simulations are still unable to explain everything we know about the Moon. Namely, the new simulations were able to form a Moon composed of 60 percent Earth material. But that still isn't enough to explain the extreme isotopic similarities between Earth and the Moon.
“Even a clump with 60 percent protoEarth material, with the remainder from Theia, would still be expected to produce a much larger Earth-Moon isotopic difference than what we see,” Robin Canup, assistant vice president in the SwRI Space Science and Engineering Division, told Astronomy. And while the paper suggests that material from both Theia and Earth may not have thoroughly mixed in the quickly forming Moon, creating a gradient of Earthlike material closer to the surface, Canup says that isn’t very likely. “For any portion of the Moon that forms intact, there is no opportunity for mixing between the protolunar and post-impact Earth material to remove such compositional differences.” Looking forward Determining the specifics of the Moon’s formation will require more analysis of lunar rocks plucked from unexplored regions of the Moon — something NASA's upcoming Artemis missions hope to help with. Scientists are also looking to collect samples from beneath the Moon’s surface. Combined with simulations such as these, researchers are hopeful that they will be able to solve the mystery of exactly how the Moon formed around infant Earth some 4.5 billion years ago. And, as a bonus, learning more about our celestial partner will also reveal more about Earth itself. “The more we learn about how the Moon came to be, the more we discover about the evolution of our own Earth,” said Vincent Eke, a researcher at Durham University and a co-author of the new study. “Their histories are intertwined — and could be echoed in the stories of other planets changed by similar or very different collisions.”
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Cosmology & The Universe
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This image compares two new views of the Eagle Nebula's Pillars of Creation captured by Hubble.(Left) Pillars are seen in visible light. (Right) is taken in infrared light, which penetrates much of the obscuring dust and gas and unveils a more unfamiliar view of the pillars. NASA, ESA/Hubble and the Hubble Heritage Team How the agency's next-gen space explorer could show us an unfiltered version of the cosmos. Monisha Ravisetti Science Writer Monisha Ravisetti covers all things science at CNET. On a separate note, she plays a ton of online chess and is a fan of overly complicated sci-fi movies. See full bio 6 min read As a New Yorker, I'd say trying to spot a star from Times Square is a fool's errand. To catch even the faintest glimpse of one, you'd have to squint past fluorescent street lamps, flashing billboards, stock market tickers and other illuminated distractions. You're better off taking the train a hundred or so miles upstate. Out there, stargazing no longer requires any effort. A breathtaking canopy of sparkles hangs over you, whether you like it or not. But even from the deepest, darkest, most remote location, you will never see every star with your naked eye. You physically can't spot all the galaxies, nebulae, exoplanets, quasars -- I could go on -- in your line of vision, even with your favorite off-the-shelf optical telescope. There are billions upon billions (upon billions) more cosmic phenomena out there. It's just our human eyes aren't built to see the light they emanate. It's called infrared light.Thus, quite a bit of space treasures are invisible to us. Fortunately, however, that doesn't mean they're beyond us. As Stephen Hawking once remarked, humans are unique in that we always find a way to transcend our mortal limits. We do it "with our minds and our machines." And, sure enough, over the years, astronomers have developed fascinating infrared workarounds -- ultimately paving the way for NASA's James Webb Space Telescope.Fighting a human restrictionAlready, big-budget space telescopes like NASA's Hubble and Spitzer elucidate some cosmic infrared secrets. They contain instruments that sky-scan for the elusive light, then translate that information into signals comprehensible by human pupils. This, in turn, allows us to see lots of stuff in the universe that's normally hidden to our eyes. Hubble's famous deep field image seen through the lens of infrared detection. Those bright spots aren't stars. Each one is an entire galaxy. NASA, ESA, and R. Thompson (Univ. Arizona)However, if those massive telescopes are episode one and two of astronomy's infrared detection series, the agency's powerful new Webb Space Telescope -- of which the first set of full-fledged images will be released on July 12 -- is an entirely new season.Levels beyond the Hubble and Spitzer's infrared capabilities, the JWST is literally built for the job. This image composite compares infrared and visible views of the famous Orion nebula and its surrounding cloud. The infrared picture is from NASA's Spitzer Space Telescope, and the visible image is from the National Optical Astronomy Observatory, headquartered in Tucson, Arizona. NASA/JPL-Caltech/ T. Megeath (University of Toledo, Ohio)The trailblazing telescope is a gold-plated, $10 billion machine stuffed with infrared detectors, accented with high-tech lenses and programmed with ultrapowerful software. Its holy grail device is called the Near Infrared Camera, or Nircam, and will lead the charge by collecting a wealth of deep space infrared signals for astronomers to view on the ground. This is why the JWST is often said to hold the promise of unveiling an "unfiltered universe."Looking through the JWST lens instead of a standard optical telescope would be like looking up at the stars from my hypothetical New York dark zone instead of Times Square. There'd be a myriad more sparkles in both cases, even though you're viewing the same sky. It's just that in our shadowy dark zone analogy, we're viewing extra stars because we're uninhibited by light pollution. The JWST, on the other hand, is collecting deep space infrared light and decoding it for us.It will point at the exact same universe that the Hubble has scrutinized for decades and scientists have studied for ages, but it will access luminescence we can't see, possibly revealing concealed space-borne phenomena like violent black holes, exotic exoplanets, grand spiral galaxies and... maybe even signals of alien life? Undoubtedly, its first images are poised to take much more than our breath away. In fact, NASA personnel who've already seen the JWST's "first light" images say they've been moved to tears. "What I have seen moved me, as a scientist, as an engineer and as a human being," Pam Melroy, NASA's deputy administrator, said. These NASA Hubble Space Telescope images compare two diverse views of the roiling heart of a vast stellar nursery, known as the Lagoon Nebula. On the left, is a standard optical version. On the right, infrared. NASA, ESA, and STScIBut before we get into the specifics of the JWST's infrared mechanics, we have to talk about the electromagnetic spectrum. More specifically, a bit of a conundrum that it poses for us humans. Why can't we see infrared light?At some point in your life, you might've wondered what it'd be like to see a new color. One that can't be described, the way "green" doesn't really have a definition beyond "the hue of a caterpillar," -- or, if you're an objectivity fan, "a wavelength of 550 nanometers." After some thought, I'd bet you settled into the disturbing reality that you'll never know the answer. It's because colors are nothing more than the products of light reflecting off some source. Different colors are dictated by different wavelengths of light, which you can imagine as curvy zigzags of various proportions. When we see a blue umbrella, for instance, our eyes pick up on tighter, blue wavelengths emanating from the waterproof material. While admiring a fiery sunset, our eyes take in a bunch of longer, more relaxed red and yellow wavelengths. All these wavelengths are neatly organized on what's known as "the electromagnetic spectrum." But here's the issue. This infographic illustrates the spectrum of electromagnetic energy, specifically highlighting the portions detected by NASA's Hubble, Spitzer, and Webb space telescopes. NASA and J. Olmsted [STScI]Though there's an infinite amount of light wavelengths, humans can only "see" one tiny part of the spectrum: The visible light region, which encapsulates the colors of the rainbow. That's precisely why we'll never experience the pleasure of viewing a non-rainbow color. Our bodies won't let it happen, and there's nothing we can do to change that -- except build a superpower telescope, of course.Spying on secret wavelengthsBecause infrared light falls beyond the visible light region, despite its name, it doesn't look red. It doesn't look like anything. It's actually better described as a heat signature -- we can "feel" infrared wavelengths, which is why a lot of thermal imaging equipment includes infrared detectors. Firefighters, for example, call on infrared to learn where a fire may be burning in a building without having to go inside. But specifically to astronomy, the non-visibility of infrared wavelengths is a major problem.The universe is expanding. Constantly. Which means that, as you read this, stars, galaxies and quasars -- super luminescent objects that act like cosmic flashlights -- are traveling farther and farther from Earth. And as they do that, the wavelengths of light they give off gradually stretch out from our perspective, sort of like a rubber band being pulled. They extend, recline and stretch until they shift to the red end of the spectrum. They "redshift." Our Milky Way's center is normally hidden from standard, optical telescopes due to clouds of dust and gas. But the Spitzer Space Telescope's infrared cameras were able to penetrate much of the dust, revealing stars of the crowded galactic center. The upcoming James Webb Space Telescope can offer a view even more spectacular than this -- teasing out fainter stars and sharper details. NASA, JPL-Caltech, Susan Stolovy (SSC/Caltech) et al.Take a star that was born near the beginning of time, for instance. At some point, once Earth came into existence, this star might have radiated blue light wavelengths toward our young planet. But as it got farther away, in tandem with the universe's expansion, those blue light wavelengths started to stretch from Earth's vantage point, getting redder... and redder... and redder. "Redshifting is the stretching of light toward longer wavelengths that occurs as light travels through the expanding universe, and can be used to gauge distance," Paul Geithner, deputy project manager for the JWST, said in a statement. In fact, he said the JWST's Nircam, "will take a series of pictures using filters that pick up different wavelengths, and use the changes in brightness it detects between these images to estimate the redshifts of the distant galaxies." Eventually, however, these wavelengths stretch even beyond the visible light spectrum. They tread into infrared waters -- and they disappear from the view of our naked eye. Consider that ancient star example again. Now, billions of years later, those slowly reddening wavelengths have moved all the way into the infrared region of the spectrum, from our perspective. The ancient star is only sending us the kind of starlight our eyes can't see. You can see an image from all of Webb's major instruments in this collage. These aren't the telescope's final, full-color "first light" results. They're just testing products. NASA/STScIStars and galaxies, MIAWhat this means is that all the distant, super rare and probably information-rich stars and galaxies are invisible to us, along with everything illuminated by those stars and galaxies. We're the missing pieces of our universe's history -- its beginning chapters. But thanks to its infrared-hunting instruments, the JWST's infrared detectors could show us those missing pieces. They could elucidate what the cosmos looked like during its first moments after the Big Bang. They could also find distant exoplanets floating among their own exomoons and search for far away artificial light that may signal extraterrestrial life. They will offer us a landscape of the universe that's clear enough to remind us of our microscopic place in it. A comparison of Hubble's visible and infrared views of the Monkey Head Nebula. While the Hubble has some infrared capabilities, it's nothing compared to the Webb. NASA and ESAPlus, to take everything a step further, infrared wavelengths have the added benefit of being long enough to travel through matter, including thick, enormous stardust clouds. Thus, if the JWST picks up on infrared light radiating from such a cloud, it'd be able to paint a picture of the scene within -- perhaps, even, a scene of ancient stars being born."It is not clear how the universe transformed from a simpler state of nothing but hydrogen and helium to the universe we see today," Geithner said. "[T]he Webb telescope will see distant reaches of space and an epoch of time never observed before and help us answer these important questions."But the most coveted aspect of the JWST is that, in addition to questions scientists have been asking for decades, it could very well answer a few no one thought to ask.
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Cosmology & The Universe
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By Geraint Lewis, University of Sydney & Prajwal R. Kafle, Univeristy of Western AustraliaHow did large galaxies, like our own Milky Way and the nearby Andromeda Galaxy, emerge from the featureless soup that existed after the birth of our universe?Decades of observations and theoretical effort have provided a picture in which atoms pool into galaxies, drawn by the gravitational pull of dark matter. Our synthetic universes, created and evolved on the most powerful supercomputers, beautifully match the distribution of galaxies we see on the universe.Understanding the small-scale detail is going to occupy astronomers for decades to come, but it appears that galaxies are built up over time by accreting (gathering) smaller systems that stray too close.And in the past few decades, it has become clear that the tenuous stellar halo that surrounds large galaxies holds the clues to unravelling galaxies accretion history Dissecting galaxiesA big spiral galaxy can be split into three key pieces: the bulge, the disk and the halo.The bulge and disk are home to the vast majority of the hundreds of billions of stars that make up the galaxy, whereas only 1% of the stars can be found in the halo that envelopes a galaxy.The halo hosts some of the oldest stars to be found in a galaxy. It is also home to globular clusters, the oldest bound groups of stars we know in the universe.These suggest that the halo was the first galactic component to form, and it should hold some of the best preserved record for the formation history of a galaxy.But to reveal the secrets hidden within a galaxy, astronomers have to take a forensic approach and look at the stellar halo like a crime scene. Galactic cannibalsIt is within the stellar halo that smaller dwarf galaxies meet their ultimate fate, losing their battle with the destructive forces of gravity.These dwarf galaxies are stripped, harassed and dispersed until they eventually mix with the stars of the larger galaxy.But this destruction, this galactic cannibalism, can take many billions of years, and we expect to catch the ongoing destruction of dwarf galaxies even today.There is observational evidence for the existence of a range of substructures in galaxy halos, such as tidal streams and stellar shells, revealed in our own Milky Way and the neighbouring Andromeda Galaxy.It is within these galaxies that we can identify and isolate individual stars within the extremely faint halo. And it was the halo of Andromeda that formed the focus for our new study published recently.A search for clusteringInstead of stars, we used a map of the planetary nebulae that also inhabit the halo of Andromeda.These are the late-stage evolution of stars similar to our own sun, stars that are the debris of disrupting and disrupted dwarf galaxies. Luckily, these are readily identifiable due to their peculiar spectral signature, a signature that also reveals their velocities.We needed to pick over these galactic corpses, dissecting the crime scene to work out just how many victims lay hidden in plain sight.To do this, we looked for how “clustered” these planetary nebulae are.If the picture of halos growing through accretion is correct, then we should expect an underlying smooth and unclustered distribution, the remnants of ancients accretions that have been completely disrupted and mixed, overlaid with ongoing accretions that should be clustered together in space and velocity.But there are problems. While we can see where the planetary nebulae are in the sky, and we can measure the velocity along the line-of-sight, distances are unknown, as are the proper motions in the plane of the sky.We had to develop some clever methods to search for clustering signatures, and compare these to expectations drawn from synthetic models of galaxies.And success! The results revealed a mix of smoothly scrambled and lumpy clustered planetary nebulae, precisely in accordance with our cosmological expectations.This provides further evidence for our current best explanation for the cosmos, the Lambda Cold Dark Matter cosmological model, a universe dominated by the gravitational pull of dark matter battling the expansion of the universe, and where galaxies have been steadily built up over time through devouring smaller systems.While this success is heartening, with growing evidence that our understanding of the workings of the universe is well founded, tensions remain. This is particularly so on the scale of individual halos of large galaxies – the recently discovered coordinated dance of dwarf galaxies still cries out for an answer.Astronomical effort will continue over the next few decades, but on the question of when we will truly understand galaxy formation and evolution, the jury is still out.Source: The Conversation
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Cosmology & The Universe
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Massimo Pascale wasn’t planning to study the galaxy cluster SMACS 0723. But as soon as he saw the cluster glittering in the first image from the James Webb Space Telescope, or JWST, he and his colleagues couldn’t help themselves. “We were like, we have to do something,” says Pascale, an astronomer at the University of California, Berkeley. “We can’t stop ourselves from analyzing this data. It was so exciting.” Pascale’s team is one of several groups of scientists who saw the first JWST images and immediately rolled up their sleeves. In the first few days after images and the data used to create them were made public, scientists have estimated the amount of mass the cluster contains, uncovered a violent incident in the cluster’s recent past and estimated the ages of the stars in galaxies far beyond the cluster itself. “We’ve been preparing for this for a long time. Myself, I’ve been preparing for years, and I’m not very old,” says Pascale, who is in his fourth year of graduate school. JWST “is really going to define a new generation of astronomers and a new generation of science as a whole.” Sign Up For the Latest from Science News Headlines and summaries of the latest Science News articles, delivered to your inbox Cluster collision When the image of SMACS 0723 was released in a White House briefing on July 11, most of the focus went to extremely distant galaxies in the background (SN: 7/11/22). But smack in the middle of the image is SMACS 0723 itself, a much closer cluster of galaxies about 4.6 billion light-years from Earth. Its mass bends light from even farther away, making more distant objects appear magnified, as if their light had traveled through the lens of another cosmic-sized telescope. The light from the most distant galaxy in this image started its journey to JWST about 13.3 billion years ago — “almost at the dawn of the universe,” says astrophysicist Guillaume Mahler of Durham University in England, who is already using the picture as his Zoom background. But the image can also fill in the history of the intervening galaxy cluster itself. “People sometimes forget about that — the galaxy cluster is also very important,” Pascale says. Pascale’s and Mahler’s teams each started by taking inventory of the distant galaxies that appear stretched and distorted in the image. The light from some of those galaxies is warped such that multiple images of the same galaxy appear in different places. Mapping those multiply imaged galaxies is a sensitive probe of the way mass is spread around the cluster. That, in turn, can reveal where the cluster contains dark matter, the invisible, mysterious substance that makes up the majority of the mass in the universe (SN: 9/10/20). Both teams found that SMACS 0723 is more elongated than it appeared in previous observations. They also found a faint glow, called intracluster light, inside the cluster from stars that don’t belong to any particular galaxy. Together, those features suggest that SMACS 0723 is still recovering from a relatively recent smash-up with another galaxy cluster, the teams report separately in a pair of papers submitted to arXiv.org on July 14. A galaxy cluster that has been sitting on its own for eons should have a rounder distribution of matter and intracluster light, rather than SMACS 0723’s oblong shape. The stars that emit the intracluster light were probably ripped from their home galaxies by gravitational forces during the collision. “Two separate clusters have merged together, and it looks to us as if it’s not totally settled yet,” Pascale says. “What we might be looking at is an ongoing merger.” Three examples of multiply imaged galaxies — marked with white, red and yellow arrows — popped out of this small region of the first JWST image. The gravity from a foreground galaxy cluster distorted the light from these galaxies, making them appear in at least two places at once.Reproduced from M. Pascale et al/arXiv.org 2022 Far-flung galaxies Mapping out mass in the cluster is also essential to decoding the properties of the more distant galaxies in the background of the image, Mahler says. “You need to understand the cluster and its magnification power to understand what’s behind.” Some scientists are already investigating those distant galaxies in detail. The first JWST data include not just pretty pictures but also spectra, measurements of how much light an object emits at various wavelengths. Spectra allow scientists to determine how much a distant object’s light has been stretched — or redshifted — by the expansion of the universe, which is a proxy for its distance. Such data can also help reveal a galaxy’s composition and the ages of its stars. “The main thing that limits the study of star formation in galaxies is the quality of the data,” says astrophysicist Adam Carnall of the University of Edinburgh. But with the vastly improved data from JWST, he says, he and his team were able to measure the ages of stars in those remote galaxies. Carnall and colleagues turned their attention to the spectra of the distant galaxies just a few days after the SMACS image was released. They measured the redshifts of 10 galaxies, five of which were particularly distant, the team reports in a paper submitted to arXiv.org on July 18. One had already been highlighted as the most distant galaxy ever seen, with light that was emitted just 500 million years after the Big Bang 13.8 billion years ago. The other four shone as late as 1.1 billion years after the Big Bang. All 10 galaxies were relatively young when they emitted the light captured by JWST, Carnall says. They had all switched on their star formation just a few million years earlier. That’s not especially surprising, but it is interesting. “The ability to look at these small, faint galaxies … gives you a sense of how all galaxies must look when they start forming stars,” Carnall says. Scientists hope to use JWST to find the first instances of star formation ever. Other early results suggest they’re already getting close. Some galaxies in a JWST image of another cluster may hearken from an even earlier time, as early as 300 million years after the Big Bang, two research teams report in a pair of papers submitted to arXiv.org on July 19. One of those galaxies seems to have already built up a spiral disk about a billion times the mass of the sun, which is surprisingly mature for such an early galaxy. And a tally of galaxies seen in the SMACS 0723 image suggests that galaxies with mature disks, rather than disorganized blobs or ones made up mostly of dark matter, may have been more common in the very early universe than previously thought, another team reports in an arXiv.org paper submitted July 19. That means those early disks might not be outliers. “Definitely these galaxies are a big deal, but it remains to be seen how exciting they will look in the context of a few months’ progress with JWST,” Carnall says. The best is yet to come.
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Cosmology & The Universe
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Key pointsNASA to share first images from new James Webb Space TelescopePictures from the most powerful telescope in history due at 3.30pmThe very first image was revealed by President Biden on MondayAnalysis by Tom Clarke: Why is this such a big deal?Updates from Tom Clarke, science editor, and Jess Breadman, producer, at NASA Goddard. Live reporting by Emily Mee, live blogger, and Alexander Martin, technology reporter A statuette of the telescope is given a dusting off... How much better is JWST compared to Hubble? Dr Kelvin Getley has shared what he described as a rough comparison of the improvement between the images captured by the Hubble and James Webb space telescopes. Astronomers bursting with excitement after 'amazing teaser' Dr Nathan Adams, a research associate at the University of Manchester, said: "Within minutes I was awash with notifications from my colleagues about the noticeable improvement in depth compared to Hubble."With just a simple picture, people are already finding galaxies which previously didn't show up in the imaging we had of this patch of sky. I can't wait to see what we can do when we get hold of these images properly!"Dr Aayush Saxena, a research fellow in extragalactic astronomy at University College London, said: "It was incredible to see this stunning multi-colour image of the galaxy cluster, complete with beautiful 'arcs' that arise due to the bending of light from objects that lie behind massive clusters of galaxies."To be able to achieve such sensitivity and resolution at infrared wavelengths is truly paradigm shifting, opening up a whole range of possibilities. These capabilities will be revolutionary to detect some of the first galaxies to have formed in the Universe. "Overall, this was an amazing teaser of JWST's revolutionary capabilities, and I cannot wait to see more data." 'Absolute scenes' ahead of unveiling Our science and technology editor Tom Clarke is at the NASA Goddard Space Flight Centre in Maryland, where the new images are set to be revealed soon...There are some absolute scenes going on here. Eighteen NASA staff have just come into the room, each of them dressed as one of the 18 hexagonal mirrors that make James Webb's massive 6.5 metre-wide light-gathering mirror.It's that that will be bringing us these incredible images we should be getting in under an hour now. There's a real sense of genuine excitement in this room. It's filled with scientists, engineers, cosmologists, astrophysicists, the people who built the telescope, the people who are going to learn from the science, but there are also politicians. It's going to give us a completely new view of the universe. One of the images we're expecting to see today is likely to feature the oldest object ever imaged - maybe 13.23 billion years old. The first image 'a minor glimpse of what is to come' Yesterday's picture from the James Webb Space Telescope was "just the start of a marathon of amazing images that will reveal the deepest wonders of the universe", said Dr Hannah Wakeford."The first image is a minor glimpse of what is to come," added Dr Wakeford, an exoplanet specialist from the University of Bristol."Twelve and a half hours to look back over 13 billion years of time. In that image is thousands of galaxies, billions of stars and trillions of planets. How can you not be in awe?" How will the JWST help search for alien life? The James Webb Space Telescope is equipped with a powerful infrared telescope that is designed to "explore a wide range of science questions to us understand the origins of the universe and our place in it", says NASA."Webb will directly observe a part of space and time never seen before. Webb will gaze into the epoch when the very first stars and galaxies formed, over 13.5 billion years ago."Ultraviolet and visible light emitted by the very first luminous objects has been stretched or 'redshifted' by the universe’s continual expansion and arrives today as infrared light," adds NASA, and Webb's telescope is designed to detect that kind of light "with unprecedented resolution and sensitivity".The JWST is also going to be used "to study planets and other bodies in our solar system to determine their origin and evolution and compare them with exoplanets, planets that orbit other stars".Webb will also observe exoplanets located in their stars' habitable zones, the regions where a planet could harbour liquid water on its surface, and can determine if and where signatures of habitability may be present.It will use a technique called transmission spectroscopy to observe starlight filtered through planetary atmospheres.Because the molecules in the atmosphere absorb particular wavelengths of light, whatever gets filtered through will reveal the chemical compositions of those atmospheres, and potentially indicate if the planet is capable of harbouring life. President Biden presents first NASA image "That blows my mind... a million miles into the cosmos," he said. The deepest and sharpest infrared image of the universe to date The very first image captured by the James Webb Space Telescope was shared by President Biden on Monday evening.He described it as representing "a historic moment for science and technology" and "for astronomy and space exploration" - as well as "for America and all humanity".NASA administrator Bill Nelson said: "We're looking back more than 13 billion years... and we're going further... this is just the first image and since we know the universe is 13.8 billion years old, we're going back almost to the beginning."It is going to be so precise you are going to see whether or not planets are habitable. And when you look at something as big as this we're going to be able to answer questions that we don't even know what the questions are yet." Why is this such a big deal? By Tom Clarke, science and technology editorTo those of us who aren't astronomers, it's hard to see what the big deal is.An image of points of light, coloured blobs and spirals of galaxies of the kind we're familiar with.But in fact this image is something very different indeed - it's looking further back in space and time than ever before.Read my full report on why this is so important... Hello! Good afternoon and thank you for joining us as we prepare to see the very first set of images captured by NASA's new James Webb Space Telescope. Due to your consent preferences, you’re not able to view this. Open Privacy Options
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Cosmology & The Universe
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As the universe evolves, scientists expect large cosmic structures to grow at a certain rate: dense regions such as galaxy clusters would grow denser, while the void of space would grow emptier.
But University of Michigan researchers have discovered that the rate at which these large structures grow is slower than predicted by Einstein's Theory of General Relativity.
They also showed that as dark energy accelerates the universe's global expansion, the suppression of the cosmic structure growth that the researchers see in their data is even more prominent than what the theory predicts. Their results are published in Physical Review Letters.
Galaxies are threaded throughout our universe like a giant cosmic spider web. Their distribution is not random. Instead, they tend to cluster together. In fact, the whole cosmic web started out as tiny clumps of matter in the early universe, which gradually grew into individual galaxies, and eventually galaxy clusters and filaments.
"Throughout the cosmic time, an initially small clump of mass attracts and accumulates more and more matter from its local region through gravitational interaction. As the region becomes denser and denser, it eventually collapses under its own gravity," said Minh Nguyen, lead author of the study and postdoctoral research fellow in the U-M Department of Physics.
"So as they collapse, the clumps grow denser. That is what we mean by growth. It's like a fabric loom where one-, two- and three-dimensional collapses look like a sheet, a filament and a node. The reality is a mixture of all three cases, and you have galaxies living along the filaments while galaxy clusters—groups of thousands of galaxies, the most massive objects in our universe bounded by gravity—sit at the nodes."
The universe is not only made of matter. It also likely contains a mysterious component called dark energy. Dark energy accelerates the expansion of the universe on a global scale. As dark energy accelerates the expansion of the universe, it has the opposite effect on large structures.
"If gravity acts like an amplifier enhancing matter perturbations to grow into large-scale structure, then dark energy acts like an attenuator damping these perturbations and slowing the growth of structure," Nguyen said. "By examining how cosmic structure has been clustering and growing, we can try to understand the nature of gravity and dark energy."
First, the team used what's called the cosmic microwave background. The cosmic microwave background, or CMB, is composed of photons emitted just after the Big Bang. These photons provide a snapshot of the very early universe. As the photons travel to our telescopes, their path can become distorted, or gravitationally lensed, by large-scale structure along the way. Examining them, the researchers can infer how structure and matter between us and the cosmic microwave background are distributed.
Nguyen and colleagues took advantage of a similar phenomenon with weak gravitational lensing of galaxy shapes. Light from background galaxies is distorted through gravitational interactions with foreground matter and galaxies. The cosmologists then decode these distortions to determine how the intervening matter is distributed.
"Crucially, as the CMB and background galaxies are located at different distances from us and our telescopes, galaxy weak gravitational lensing typically probes matter distributions at a later time compared to what is probed by CMB weak gravitational lensing," Nguyen said.
To track the growth of structure to an even later time, the researchers further used motions of galaxies in the local universe. As galaxies fall into the gravity wells of the underlying cosmic structures, their motions directly track structure growth.
"The difference in these growth rates that we have potentially discovered becomes more prominent as we approach the present day," Nguyen said. "These different probes individually and collectively indicate a growth suppression. Either we are missing some systematic errors in each of these probes, or we are missing some new, late-time physics in our standard model."
The findings potentially address the so-called S8 tension in cosmology. S8 is a parameter that describes the growth of structure. The tension arises when scientists use two different methods to determine the value of S8, and they do not agree. The first method, using photons from the cosmic microwave background, indicates a higher S8 value than the value inferred from galaxy weak gravitational lensing and galaxy clustering measurements.
Neither of these probes measures the growth of structure today. Instead, they probe structure at earlier times, then extrapolate those measurements to present time, assuming the standard model. Cosmic microwave background probes structure in the early universe, while galaxy weak gravitational lensing and clustering probe structure in the late universe.
The researchers' findings of a late-time suppression of growth would bring the two S8 values into perfect agreement, according to Nguyen.
"We were surprised with the high statistical significance of the anomalous growth suppression," Huterer said. "Honestly, I feel like the universe is trying to tell us something. It is now the job of us cosmologists to interpret these findings.
"We would like to further strengthen the statistical evidence for the growth suppression. We would also like to understand the answer to the more difficult question of why structures grow slower than expected in the standard model with dark matter and dark energy. The cause of this effect may be due to novel properties of dark energy and dark matter, or some other extension of General Relativity and the standard model that we have not yet thought of."
Journal
Physical Review Letters
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Cosmology & The Universe
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GREENBELT, Md. (AP) — A sparkling landscape of baby stars. A foamy blue and orange view of a dying star. Five galaxies in a cosmic dance. The splendors of the universe glowed in a new batch of images released Tuesday from NASA’s powerful new telescope.The unveiling from the $10 billion James Webb Space Telescope began Monday at the White House with a sneak peek of the first shot — a jumble of distant galaxies that went deeper into the cosmos than humanity has ever seen.Tuesday’s releases showed parts of the universe seen by other telescopes. But Webb’s sheer power, distant location from Earth and use of the infrared light spectrum showed them in a new light.“It’s the beauty but also the story,” NASA senior Webb scientist John Mather, a Nobel laureate, said after the reveal. “It’s the story of where did we come from.”(Produced by Cody Jackson)And, he said, the more he looked at the images, the more he became convinced that life exists elsewhere in those thousands of stars and hundreds of galaxies.With Webb, scientist hope to glimpse light from the first stars and galaxies that formed 13.7 billion years ago, just 100 million years from the universe-creating Big Bang. The telescope also will scan the atmospheres of alien worlds for possible signs of life.“Every image is a new discovery and each will give humanity a view of the humanity that we’ve never seen before,” NASA Administrator Bill Nelson said Tuesday, rhapsodizing over images showing “the formation of stars, devouring black holes.”Webb’s use of the infrared light spectrum allows the telescope to see through the cosmic dust and see faraway light from the corners of the universe, he said.“We’ve really changed the understanding of our universe,” said European Space Agency director general Josef Aschbacher. The European and Canadian space agencies joined NASA in building the telescope, which was launched in December after years of delays and cost overruns. Webb is considered the successor to the highly successful, but aging Hubble Space Telescope. Shown Tuesday: — Southern Ring nebula, which is sometimes called “eight-burst.” Images show a dying star with a foamy edge of escaping gas. It’s about 2,500 light-years away. A light-year is 5.8 trillion miles. — Carina nebula, one of the bright stellar nurseries in the sky, about 7,600 light-years away. One view was a stunning landscape of orange cliffs.— Stephan’s Quinet, five galaxies in a cosmic dance that was first seen 225 years ago in the constellation Pegasus. It includes a black hole that scientists said showed material “swallowed by this sort of cosmic monster.” Webb “has just given us a new, unprecedented 290 million-year-old view of what this Quintet is up to,” Cornell University astronomer Lisa Kaltenegger, who wasn’t part of the Webb team, said in an email.— A giant planet called WASP-96b. It’s about the size of Saturn and is 1,150 light-years away. A gas planet, it’s not a candidate for life elsewhere but a key target for astronomers. Instead of an image, the telescope used its infrared detectors to look at the chemical composition of the planet’s atmosphere. It showed water vapor in the super-hot planet’s atmosphere and even found the chemical spectrum of neon.The images were released one-by-one at an event at NASA’s Goddard Space Center that included cheerleaders with pompoms the color of the telescope’s golden mirrors.“It moves you. This is so so beautiful,” Thomas Zurbuchen, chief of NASA’s science missions, said after the event. “Nature is beautiful. To me this is about beauty.”The world’s biggest and most powerful space telescope rocketed away last December from French Guiana in South America. It reached its lookout point 1 million miles (1.6 million kilometers) from Earth in January. Then the lengthy process began to align the mirrors, get the infrared detectors cold enough to operate and calibrate the science instruments, all protected by a sunshade the size of a tennis court.___The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.
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Cosmology & The Universe
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On Christmas Day last year, 30 years after its conception, the James Webb space telescope launched from French Guiana. On 28 December, it went past the moon. On 24 January, it fired its thrusters for five minutes and settled into its final orbit about 1.5m km from Earth. On 12 July, after months of painstaking setup, it produced its first image – showing us, for the first time, faraway galaxies as they were more than 13bn years ago.The Webb telescope has been adding to this miraculous beginning ever since. Now it’s brought us something a little closer to home, a mere 615m km away: the most extraordinarily detailed images of Jupiter we’ve ever seen.The James Webb space telescope is packed up for shipment to its launch site in Kourou, French Guiana. Photograph: Chris Gunn/Nasa/ReutersOxford University astrophysicist Dr Becky Smethurst, author of a forthcoming book, A Brief History of Black Holes, said that there were many reasons to be sceptical that it would ever get this far. “There were 344 single points of failure where if any tiny thing had gone wrong, the whole mission would have been scrapped. It was months of anxiety,” she said.One major source of uncertainty after the satellite launched was how closely it would hew to its intended trajectory – with any inaccuracy bringing with it the need to burn valuable fuel. “But it was perfect. We were promised five years of data, and instead we’re going to get 20. It’s just incredible.” Here are some of the images this impeccably directed telescope has produced – and what they show about how it operates, and the universe itself.Webb’s First Deep FieldWebb’s First Deep Field, which showcases a galaxy cluster called SMACS 0723 as it appeared 4.6bn years ago. Photograph: ESA/PAThe first of the Webb images to be revealed – by Joe Biden – shows a galaxy cluster known as SMACS 0723. The entire picture covers thousands of galaxies in an area of the sky equivalent to a single grain of rice held at arm’s length on the surface of the Earth. “We can see things in this tiny, tiny patch in way more detail than we’ve ever been able to with Hubble [the most powerful telescope until now],” Smethurst said. “It suggests there’s no blank sky any more – everywhere you look, you’re going to find something in the background.”Like all of the images produced by Webb, what you can see here is not visible light – but signals in the infrared spectrum captured by the satellite in monochrome, sent back to Earth as ones and zeros, and then reconstructed. The different colours don’t denote literal shades, but the wavelengths of the signals, which tell us how hot the source was. Colouring the images like this makes it easier for scientists to detect areas for further study (and generates more public excitement than a black-and-white picture ever could).In this image, the sharp, gleaming star at the centre is in our own galaxy. The fuzzy white dots below it are whole galaxies in the SMACS 0723 cluster, shown as they were some 4.6bn years ago. Better still, this cluster in the centre acts as a kind of magnifying lens for other galaxies which are much further away – as much as 13bn light years, almost back to the dawn of the universe. Because they are distorted in the process, they show as the arcs streaking across the image: red objects are caked in cosmic dust – a crucial ingredient of star formation – while green ones are full of hydrocarbons. The Carina NebulaA comparison of the James Webb telescope’s views of the Carina Nebula with Hubble’s equivalent. Photograph: NasaThe comparison of this image of a nebula – a vast cloud of dust and gas studded with stars – to the equivalent area captured by Hubble is evidence of how much more powerful Webb is. “The Carina Nebula is in our own galaxy,” Smethurst said. “Although I think it looks a bit like the Lake District here. The value of this image is really in what is shows us about the benefit of looking at relatively nearby things in infrared.“It allows you to pierce through the dust – these little molecules of heavier elements like oxygen and carbon which scatter visible light so that you can’t see the stars that have formed. In this picture, we get through that dust to the three dimensional structure of the nebula.”Stephan’s QuintetThe first image from Nasa’s James Webb telescope of Stephan’s Quintet. Photograph: Nasa/PAThis image, constructed from more than 150m pixels sent by Webb, shows a group of galaxies in the Pegasus constellation, and provides scientists with the means to see how their interaction triggers the formation of stars. “This is my favourite, because it’s directly relevant to my work,” said Smethurst. “It shows four galaxies interacting, one of them with a growing black hole, and one which isn’t. What’s amazing is that if you zoom in you can see individual stars: until now we’ve barely been able to do that with our closest galaxy, Andromeda, and these are much more distant.”The galaxy to the left of the formation is closer than the others – 40m light years away as opposed to 290m. The topmost swirl in the image contains a black hole 24m times the mass of the sun. “It’s an incredibly bright source of light,” Smethurst said. “What this shows is the gas swirling around the black hole lit up in all its glory.”WASP-96b (spectrum)A transmission spectrum made from a single observation using Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) reveals atmospheric characteristics of the hot gas giant exoplanet WASP-96 b. Photograph: Nasa/UPI/Rex/ShutterstockThis is not an image, but “it’s still enormously exciting to astrophysicists”, Smethurst says. The set of data reveals clearly that this planet, 1,150 light years away, has the distinctive characteristics of water.Webb measured light coming from the WASP-96 system as the planet moved across the star – and the way the gas giant has “stolen away a little bit of the starlight” as it passes through its atmosphere reveals the unique signature of water, Smethurst said.The findings are also important because they show “what the telescope is capable of”, Smethurst said. “This is a big bright planet, very close to its star. It’s easier to observe the light passing through the atmosphere because it passes in front of the star often. Because it’s so easy here, it suggests that with the harder ones that are further away and pass in front of their star less often like Earth, you won’t be wasting your time. It’s this idea of finding ‘Earth’s twin’ – something that looks incredibly habitable for life as we know it.”JupiterA new Jupiter photo is depicted in space with enhanced colour that showcases the planet’s features in detail. Photograph: Nasa/Zuma Press Wire Service/Rex/ShutterstockIf the primary purpose of Webb is to tell us more about light sent by faraway stars billions of year ago, it turns out to also be able to produce stunning images of our own solar system unlike any we have seen before. “I was amazed when I saw the level of detail here – I thought it would be washed out because it’s so bright,” Smethurst said. “But it’s very clever how they’ve used different wavelengths to capture different things.”The red haze at the planet’s north and south poles are auroras – created by the interaction of particles from the sun with the planet’s magnetic field. The famous Great Red Spot, a storm so big it could swallow Earth, appears in white because it reflects so much sunlight. “And the darker areas reveal the areas where the light has pierced further into the atmosphere,” Smethurst said.Valuable though Webb’s observations will be for scientists, images like this also strike Smethurst as important for their sheer, universal beauty. “Everyone is curious about the world we live in,” she said.
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Cosmology & The Universe
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A camera built to uncover dark energy in the universe has captured a stunning new image of a star-forming region nicknamed 'Lobster Nebula'. The impressive image shows a region 400 light-years across, with scattered stars intertwined with dust and clouds. The centre shows what astronomers call an open star cluster, a name to describe a group of huge and forming stars. The tiny speckles dotted around are baby stars that haven't fully emerged yet. The National Science Foundation’s (NSF) NOIRLab is responsible for the camera and is the "ground-based optical-infrared astronomy, enabling breakthrough discoveries in astrophysics by developing and operating state-of-the-art ground-based observatories and providing data products and services for a diverse and inclusive community."Sign up to our free Indy100 weekly newsletterNOIRLab/ CTIO/NOIRLab/DOE/NSF/AURA/CC BY 4.0According to NOIRLab, DECam was specifically for the Dark Energy Survey and was operated by the Department of Energy (DOE) and the National Science Foundation (NSF) between 2013 and 2019.The high-performance camera can deliver 400 to 500 images per night. "It boasts 62 science CCDs and 12 CCDs for guiding and focus, with 570 megapixels, and images a 3-square-degree field (2.2 degrees wide) at a resolution of 0.263 arcsecond per pixel. DECam is a facility instrument, available to all users," they wrote. Astronomers believe that dark energy accelerates the expansion of the universe. Such images help scientists study how distant objects move in space. According to NASA, "It turns out that roughly 68 per cent of the universe is dark energy. Dark matter makes up about 27 per cent. The rest—everything on Earth, everything ever observed with all of our instruments, all normal matter—adds up to less than 5 per cent of the universe."Have your say in our news democracy. Click the upvote icon at the top of the page to help raise this article through the indy100 rankings.
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Cosmology & The Universe
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The first images from the Euclid space telescope have been revealed, and they are stunning.
The European Space Agency (ESA) telescope, which launched on July 1 on a SpaceX Falcon 9 rocket, is designed to explore the composition and evolution of the "dark universe" — the collective name given to dark matter and dark energy.
This is one of the most pressing issues in modern cosmology: Together, dark matter and dark energy comprise around 95% of the "stuff" in the universe, yet scientists can't see them and have very little idea what they actually are. Dark matter and dark energy also play a significant role in the evolution and structure of the visible 5% of the universe — such as stars, planets, galaxies and even our bodies.
"Dark matter pulls galaxies together and causes them to spin more rapidly than visible matter alone can account for; dark energy is driving the accelerated expansion of the universe," Carole Mundell, ESA's director of science, said in a statement. "Euclid will, for the first time, allow cosmologists to study these competing dark mysteries together."
"Euclid will make a leap in our understanding of the cosmos as a whole, and these exquisite Euclid images show that the mission is ready to help answer one of the greatest mysteries of modern physics," Mundell added.
These first images show that Euclid, located at a gravitationally stable point between Earth and the sun about 1 million miles (1.5 million kilometers) from our planet, is off to an excellent start.
The Perseus galaxy cluster
The first image released from the Euclid telescope features 1,000 galaxies that are part of the Perseus cluster, located around 240 million light-years from Earth. In the background of the image are a further 100,000 galaxies located at even greater distances.
Many of these galaxies have never been seen before, and some are so far away that their light has traveled for around 10 billion years to reach us.
This is the first time so many Perseus galaxies have been spotted in great detail and in the same image. Mapping the distribution and shape of these galaxies could help scientists determine the role of dark matter in sculpting that part of the universe.
The "hidden" spiral galaxy IC 342
The next Euclid image features the spiral galaxy IC 342, also known as the "Hidden Galaxy" or Caldwell 5.
IC 342, located around 10.8 million light-years away, is tough to spot because it is hidden behind stars, gas and dust in the plane of the Milky Way. Using its near-infrared instrument, Euclid peered through these obstructions to reveal previously unseen details of IC 342's steller occupants.
The irregular galaxy NGC 6822
As Euclid looks deeper into the cosmos and further back in the history of the universe, neat spiral galaxies like our own and IC 342 should become less common, and instead irregular, blob-like galaxies should appear more often.
Euclid's third recently released image shows just such an irregular galaxy, NGC 6822 — but this blobby galaxy is located just 1.6 million light years from Earth.
The globular cluster NGC 6397
In another stunning image from the space telescope, a globular cluster — a tightly gravitationally bound collection of hundreds or even thousands of stars — is captured in breathtaking detail.
This particular globular cluster, NGC 6397, is located around 7,800 light-years from Earth, making it the second-closest globular cluster to our planet. Euclid will shed new light on globular clusters, as it is the only current telescope able to observe every star in such a collection in fine detail. This could help scientists map the distribution of dark matter through the Milky Way as the development of these clusters is molded by the gravitational influence of dark matter.
The Horsehead Nebula
In perhaps the most colorful image from Euclid's first set of observations, the Horsehead Nebula is shown in vibrant detail. Also known as Barnard 33, the nebula is a stellar nursery of hot, young stars located in the Orion Nebula — which at between 1,500 and 1,350 light-years away is the closest star-forming region to Earth.
Alongside its work studying the dark universe, Euclid will search regions like this for Jupiter-mass planets, young "failed star" brown dwarfs and infant stars.
"We have never seen astronomical images like this before, containing so much detail," René Laureijs, ESA's Euclid project scientist, said in the statement. "They are even more beautiful and sharp than we could have hoped for, showing us many previously unseen features in well-known areas of the nearby universe. Now we are ready to observe billions of galaxies and study their evolution over cosmic time."
Over the next six years, Euclid will investigate the dark universe by creating a map of the large-scale structure of the universe, observing billions of galaxies out to a distance of around 10 billion light-years and across over a third of the sky over Earth. This should reveal the changing structure of the universe through cosmic history, enabling scientists to determine the role dark matter and dark energy have played in this process.
Hopefully, the best is yet to come for Euclid as it helps to unravel some of the most pressing mysteries in physics and helps us see the cosmos in new detail.
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Robert Lea is a science journalist in the U.K. who specializes in science, space, physics, astronomy, astrophysics, cosmology, quantum mechanics and technology. Rob's articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University
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Cosmology & The Universe
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We’re part of an international team of astronomers who have carried out the biggest ever computer simulations from the Big Bang to the present day to investigate how the Universe evolved.
The FLAMINGO simulations calculate the evolution of all the components of the Universe – ordinary matter, like stars and planets, dark matter and dark energy – based on the laws of physics.
As the simulations progress, virtual galaxies and galaxy clusters emerge in precise detail.
It’s hope hoped the simulations will allow researchers to compare the virtual Universe with observations of the real thing being captured by new high-powered telescopes, like the James Webb Space telescope.
This could help scientists understand if the standard model of cosmology – used to explain the evolution of the Universe – provides an accurate description of reality.
Previous simulations, which have been compared to observations of the Universe, have focused on cold dark matter - believed to be a key component of the structure of the cosmos.
However, astronomers now say that the effects of ordinary matter, which makes up only sixteen per cent of all matter in the Universe, and neutrinos, tiny particles that rarely interact with normal matter, also need to be taken into account when trying to understand the Universe’s evolution.
The FLAMINGO simulations, carried out on the Cosmology Machine supercomputer at Durham over the past two years, tracked the formation of the Universe’s structure in dark matter, ordinary matter and neutrinos, following the standard model of physics.
The team ran the simulations using different resolutions and also altered other factors such as the strength of galactic winds and the mass of the neutrinos.
The first results showed that the inclusion of ordinary matter and neutrinos in the simulations was essential for making accurate predictions.
New telescopes, such as the international “Dark Energy Survey Instrument” (in which Durham is a partner) and the European Space Agency’s Euclid space telescope, are collecting huge amounts of data about galaxies, quasars and stars, and these observations are posing questions about the theories behind the current understanding of the evolution of the Universe.
Simulations like FLAMINGO will play a key role in interpreting these data by comparing theoretical predictions with observational data.
Read more about FLAMINGO’s research in these three papers, published in the journal Monthly Notices of the Royal Astronomical society – paper one, paper two, paper three.
Durham University is a collaborator on FLAMINGO which also involves the University of Leiden, the Netherlands, and Liverpool John Moores University. The FLAMINGO simulations were run on the Cosmology Machine (COSMA 8) supercomputer, hosted by the Institute for Computational Cosmology at Durham University on behalf of the UK’s DiRAC High-Performance Computing facility.
The simulations took more than 50 million processor hours on COSMA 8 over the past two years. To make the FLAMINGO simulations possible, the researchers developed a new code, called SWIFT, which efficiently distributes the computational work over thousands of Central Processing Units (CPUs, sometimes as many as 65,000).
Funding for FLAMINGO came from the European Research Council, the UK’s Science and Technology Facilities Council, the Netherlands Organization for Scientific Research and the Swiss National Science Foundation.
Our Department of Physics is a thriving centre for research and education. Ranked 2nd in the UK in The Guardian University Guide 2024 and in the World Top 100 in the QS World University Rankings by Subject 2023. We are proud to deliver a teaching and learning experience for students which closely aligns with the research-intensive values and practices of the University. Feeling inspired? Visit our Physics webpages to learn more about our postgraduate and undergraduate programmes. Durham University is a top 100 world university. In the QS World University Rankings 2024, we were ranked 78th globally.
Banner image: A projection of the Universe through a 130 million light years thick slice through a simulation of a cubic volume of 9,132 million light years. Credit: Josh Borrow, the FLAMINGO team and the Virgo Consortium.
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Cosmology & The Universe
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Trending Now Now playing This is where Perseverance found more organic matter than ever on Mars Now playing Emmy winner Quinta Brunson interrupts Jimmy Kimmel's monologue KNXV Now playing See husky dog play on the roof of house in the absence of a backyard Brookfield Zoo Now playing Otter and ape make for cute odd couple at zoo Now playing Actor loses bet, agrees to get colonoscopy on camera wgme Now playing See moment shark jumps onto fishing boat in Maine Twitter/FilmThePoliceLA Now playing Watch: Delivery robot rolls through crime scene Now playing Tow truck lifts massive alligator out of Texas neighborhood Now playing Videos of young Black girls reacting to 'Little Mermaid' trailer go viral Now playing Watch 'Abbott Elementary' star's epic acceptance speech Now playing The Queen's corgis have a new home Now playing See Drew Barrymore's tearful reunion with ex-boyfriend Getty Images Now playing Film director Jean-Luc Godard dead at 91 Robert Durst Now playing Unexpected bear shows up at 2-year-old's birthday party Now playing From werewolves to Jedi masters to secret wars, Disney just revealed a lot Reuters Now playing See moment woman kisses King Charles outside palace Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. CNN — Investigating the site of an ancient river delta, the Perseverance rover has collected some of the most important samples yet on its mission to determine if life ever existed on Mars, according to NASA scientists. A few of the recently collected samples include organic matter, indicating that Jezero Crater, which likely once held a lake and the delta that emptied into it, had potentially habitable environments 3.5 billion years ago. “The rocks that we have been investigating on the delta have the highest concentration of organic matter that we have yet found on the mission,” said Ken Farley, Perseverance project scientist at the California Institute of Technology in Pasadena. The rover’s mission, which began on the red planet 18 months ago, includes looking for signs of ancient microbial life. Perseverance is collecting rock samples that could have preserved these telltale biosignatures. Currently, the rover contains 12 rock samples. A series of missions called Mars Sample Return will eventually take the collection back to Earth in the 2030s. The site of the delta makes Jezero Crater, which spans 28 miles (45 kilometers), of particularly high interest to NASA scientists. The fan-shaped geological feature, once present where a river converged with a lake, preserves layers of Martian history in sedimentary rock, which formed when particles fused together in this formerly water-filled environment. The rover investigated the crater floor and found evidence of igneous, or volcanic, rock. During its second campaign to study the delta over the past five months, Perseverance has found rich sedimentary rock layers that add more to the story of Mars’ ancient climate and environment. “The delta, with its diverse sedimentary rocks, contrasts beautifully with the igneous rocks – formed from crystallization of magma – discovered on the crater floor,” Farley said. “This juxtaposition provides us with a rich understanding of the geologic history after the crater formed and a diverse sample suite. For example, we found a sandstone that carries grains and rock fragments created far from Jezero Crater.” The mission team nicknamed one of the rocks that Perseverance sampled as Wildcat Ridge. The rock likely formed when mud and sand settled in a saltwater lake as it evaporated billions of years ago. The rover scraped away at the surface of the rock and analyzed it with an instrument known as the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals, or SHERLOC. This rock-zapping laser functions as a fancy black light to uncover chemicals, minerals and organic matter, said Sunanda Sharma, SHERLOC scientist at NASA’s Jet Propulsion Laboratory in Pasadena. The instrument’s analysis revealed that the organic minerals are likely aromatics, or stable molecules of carbon and hydrogen, which are connected to sulfates. Sulfate minerals, often found sandwiched within the layers of sedimentary rocks, preserve information about the watery environments they formed in. Organic molecules are of interest on Mars because they represent the building blocks of life, such as carbon, hydrogen and oxygen, as well as nitrogen, phosphorous and sulfur. Not all organic molecules require life to form because some can be created through chemical processes. “While the detection of this class of organics alone does not mean that life was definitively there, this set of observations does start to look like some things that we’ve seen here on Earth,” Sharma said. “To put it simply, if this is a treasure hunt for potential signs of life on another planet, organic matter is a clue. And we’re getting stronger and stronger clues as we’re moving through our delta campaign.” Perseverance as well as the Curiosity rover has found organic matter before on Mars. But this time, the detection occurred in an area where life may have once existed. “In the distant past, the sand, mud, and salts that now make up the Wildcat Ridge sample were deposited under conditions where life could potentially have thrived,” Farley said. “The fact the organic matter was found in such a sedimentary rock – known for preserving fossils of ancient life here on Earth – is important. However, as capable as our instruments aboard Perseverance are, further conclusions regarding what is contained in the Wildcat Ridge sample will have to wait until it’s returned to Earth for in-depth study as part of the agency’s Mars Sample Return campaign.” The samples collected so far represent such a wealth of diversity from key areas within the crater and delta that the Perseverance team is interested in depositing some of the collection tubes at a designated site on Mars in about two months, Farley said. Once the rover drops off the samples at this cache depot, it will continue exploring the delta. Future missions can collect these samples and return them to Earth for analysis using some of the most sensitive and advanced instruments on the planet. It’s unlikely that Perseverance will find undisputed evidence of life on Mars because the burden of proof for establishing it on another planet is so high, Farley said. “I’ve studied Martian habitability and geology for much of my career and know first-hand the incredible scientific value of returning a carefully collected set of Mars rocks to Earth,” said Laurie Leshin, director of NASA’s Jet Propulsion Laboratory, in a statement. “That we are weeks from deploying Perseverance’s fascinating samples and mere years from bringing them to Earth so scientists can study them in exquisite detail is truly phenomenal. We will learn so much.” Some of the diverse rocks in the delta were about 65.6 feet (20 meters) apart, and they each tell different stories. One piece of sandstone, called Skinner Ridge, is evidence of rocky material that was likely transported into the crater from hundreds of miles away, representing material that the rover won’t be able to travel to during its mission. Wildcat Ridge, on the other hand, preserves evidence of clays and sulfates that layered together and formed into rock. Once the samples are in labs on Earth, they could reveal insights about potentially habitable Martian environments, such as chemistry, temperature and when the material was deposited in the lake. “I think it’s safe to say that these are two of the most important samples that we will collect on this mission,” said David Shuster, Perseverance return sample scientist at the University of California, Berkeley.
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Cosmology & The Universe
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First look: the James Webb Space Telescope’s first “deep field” image was released today at a special event at the White House (Courtesy: NASA, ESA, CSA, and STScI) US president Joe Biden has unveiled the first spectacular full-colour science image from the $10bn James Webb Space Telescope (JWST).
The image, known as “SMACS 0723”, is the telescope’s first “deep field” picture. It shows how massive foreground galaxy clusters magnify and distort the light of objects behind them, allowing a deep-field view into extremely distant and faint galaxy populations.
“Today is a historic day,” noted Biden at an event at the White House today. “It shows what we can achieve and what we can discover.”
“Today represents a new, exciting chapter,” noted US vice president Kamala Harris. ”We can look to the sky with a new understanding. Now we enter a new phase, building on the legacy of Hubble.”
More to come
Four other images will be released at a NASA press conference tomorrow (12 July) at 16:30 CEST.
They are an image of the Carina Nebula, which is one of the largest and brightest nebulae in the sky and is located about 7600 light-years away in the southern constellation Carina.
Another image will be the atmosphere spectra of the WASP-96b exoplanet, which was first announced in 2014. Composed mainly of gas, the planet is located nearly 1150 light-years from Earth and orbits its star every 3.4 days.
Another object that has been pictured is the Southern Ring, or “eight-burst” nebula, which is a planetary nebula almost a half a light-year in diameter and is located approximately 2000 light years away from Earth. Read more A new cosmic dawn: peering across the universe with NASA’s James Webb Space Telescope Last but not least, about 290 million light-years away is Stephan’s Quintet in the constellation Pegasus. It is the first compact galaxy group ever discovered where four of the five galaxies within the quintet often have close encounters.
The JWST was launched on 25 December 2021 and a month later it had completed most of the delicate procedures to unfold and unpack the telescope. In February, the JWST released the first unaligned picture followed in late April by the first aligned images.
The JWST is a collaboration between NASA, the European Space Agency and the Canadian Space Agency.
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Cosmology & The Universe
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There is a galaxy spinning like a record in the early universe — far earlier than any others have been seen twirling around. Astronomers have spotted signs of rotation in the galaxy MACS1149-JD1, JD1 for short, which sits so far away that its light takes 13.3 billion years to reach Earth. “The galaxy we analyzed, JD1, is the most distant example of a rotational galaxy,” says astronomer Akio Inoue of Waseda University in Tokyo. Sign Up For the Latest from Science News Headlines and summaries of the latest Science News articles, delivered to your inbox “The origin of the rotational motion in galaxies is closely related to a question: how galaxies like the Milky Way formed,” Inoue says. “So, it is interesting to find the onset of rotation in the early universe.” JD1 was discovered in 2012. Due to its great distance from Earth, its light had been stretched, or redshifted, into longer wavelengths, thanks to the expansion of the universe. That redshifted light revealed that JD1 existed just 500 million years after the Big Bang. Astronomers used light from the entire galaxy to make that measurement. Now, using the Atacama Large Millimeter/submillimeter Array in Chile for about two months in 2018, Inoue and colleagues have measured more subtle differences in how that light is shifted across the galaxy’s disk. The new data show that, while all of JD1 is moving away from Earth, its northern part is moving away slower than the southern part. That’s a sign of rotation, the researchers report in the July 1 Astrophysical Journal Letters. JD1’s spins at about 180,000 kilometers per hour, roughly a quarter the spin speed of the Milky Way. The galaxy is also smaller than modern spiral galaxies. So JD1 may be just starting to spin, Inoue says. The James Webb Space Telescope will observe JD1 in the next year to reveal more clues to how that galaxy, and others like ours, formed (SN: 10/6/21).
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Cosmology & The Universe
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The Big Bang Hypothesis - which states the universe has been expanding since it began 14 billion years ago in a hot and dense state - is contradicted by the new James Webb Space Telescope images, writes Eric Lerner.To everyone who sees them, the new James Webb Space Telescope (JWST) images of the cosmos are beautifully awe-inspiring. But to most professional astronomers and cosmologists, they are also extremely surprising—not at all what was predicted by theory. In the flood of technical astronomical papers published online since July 12, the authors report again and again that the images show surprisingly many galaxies, galaxies that are surprisingly smooth, surprisingly small and surprisingly old. Lots of surprises, and not necessarily pleasant ones. One paper’s title begins with the candid exclamation: “Panic!”Why do the JWST’s images inspire panic among cosmologists? And what theory’s predictions are they contradicting? The papers don’t actually say. The truth that these papers don’t report is that the hypothesis that the JWST’s images are blatantly and repeatedly contradicting is the Big Bang Hypothesis that the universe began 14 billion years ago in an incredibly hot, dense state and has been expanding ever since. Since that hypothesis has been defended for decades as unquestionable truth by the vast majority of cosmological theorists, the new data is causing these theorists to panic. “Right now I find myself lying awake at three in the morning,” says Alison Kirkpatrick, an astronomer at the University of Kansas in Lawrence, “and wondering if everything I’ve done is wrong.” SUGGESTED READING The Delusions of Cosmology By BjørnEkeberg It is not too complicated to explain why these too small, too smooth, too old and too numerous galaxies are completely incompatible with the Big Bang hypothesis. Let’s begin with “too small”. If the universe is expanding, a strange optical illusion must exist. Galaxies (or any other objects) in expanding space do not continue to look smaller and smaller with increasing distance. Beyond a certain point, they start looking larger and larger. (This is because their light is supposed to have left them when they were closer to us.) This is in sharp contrast to ordinary, non-expanding space, where objects look smaller in proportion to their distance.___Put another way, the galaxies that the JWST shows are just the same size as the galaxies near to us, assuming that the universe is not expanding and redshift is proportional to distance.___Smaller and smaller is exactly what the JWST images show. Even galaxies with greater luminosity and mass than our own Milky Way galaxy appear in these images to be two to three times smaller than in similar images observed with the Hubble Space Telescope (HST), and the new galaxies have redshifts which are also two to three times greater.This is not at all what is expected with an expanding universe, but it is just exactly what I and my colleague Riccardo Scarpa predicted based on a non-expanding universe, with redshift proportional to distance. Starting in 2014, we had already published results, based on HST images, that showed that galaxies with redshifts all the way up to 5 matched the expectations of non-expanding, ordinary space. So we were confident the JWST would show the same thing—which it already has, for galaxies having redshifts as high as 12. Put another way, the galaxies that the JWST shows are just the same size as the galaxies near to us, if it is assumed that the universe is not expanding and redshift is proportional to distance. SUGGESTED READING Dark Matter Doesn't Exist By PavelKroupa But from the standpoint of the Big Bang, expanding-universe hypothesis, these distant galaxies must be intrinsically extremely tiny to compensate for the hypothesized optical illusion—implausibly tiny. One galaxy noted in the papers, called GHz2, is far more luminous that the Milky Way, yet is calculated to be only 300 light years in radius—150 times smaller than the radius of our Milky Way. Its surface brightness—brightness per unit area-- would be 600 times that of the brightest galaxy in the local universe. Its density (and that of several other galaxies in the new images) would be tens of thousands of times that of present-day galaxies.___Tiny and smooth galaxies mean no expansion and thus no Big Bang.___Big Bang theorists have known for years from the HST images that their assumptions necessitate the existence of these tiny, ultra-dense “Mighty Mouse” galaxies. JWST has made the problem far worse. The same theorists have speculated that the tiny galaxies grow up into present day galaxies by colliding with each other—merging to become more spread out. An analogy to this hypothetical merger process would be to imagine a magical toy car a centimeter long that nonetheless weighs as much as a SUV and grows up into a real SUV by colliding with many other toy cars.Bang goes the Big Bang: With Roger Penrose, John Ellis and Laura Mersini-HoughtonBut the JWST has shot through this far-out scenario as well. If you could believe the toy car story, you would at least expect some fender dents in the colliding cars. And Big Bang theorists did expect to see badly mangled galaxies scrambled by many collisions or mergers. What the JWST actually showed was overwhelmingly smooth disks and neat spiral forms, just as we see in today’s galaxies. The data in the “Panic!” article showed that smooth spiral galaxies were about “10 times” as numerous as what theory had predicted and that this “would challenge our ideas about mergers being a very common process”. In plain language, this data utterly destroys the merger theory.
With few or no mergers, there is no way tiny galaxies could grow to be a hundred times bigger. Therefore, they were not tiny to begin with, and thus the optical illusion predicted from the expanding universe hypothesis does not exist. But no illusion means no expansion: the illusion is an unavoidable prediction from expansion. Thus, the panic among Big Bang supporters. Tiny and smooth galaxies mean no expansion and thus no Big Bang.
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Since nothing could have originated before the Big Bang, the existence of these galaxies demonstrates that the Big Bang did not occur.
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Too old and too many galaxies mean the same thing. The JWST uses many different filters to take its images in the infrared part of the spectrum. Thus, it can see the colors of the distant galaxies. This in turn allows astronomers to estimate the age of the stars in these galaxies because young, hot stars are blue in color and older, cooler stars, like our sun, are yellow or red in color. According to Big Bang theory, the most distant galaxies in the JWST images are seen as they were only 400-500 million years after the origin of the universe. Yet already some of the galaxies have shown stellar populations that are over a billion years old. Since nothing could have originated before the Big Bang, the existence of these galaxies demonstrates that the Big Bang did not occur.
Just as there must be no galaxies older than the Big Bang, if the Big Bang hypothesis were valid, so theorists expected that as the JWST looked out further in space and back in time, there would be fewer and fewer galaxies and eventually none—a Dark Age in the cosmos. But a paper to be published in Nature demonstrates that galaxies as massive as the Milky Way are common even a few hundred million years after the hypothesized Bang. The authors state that the new images show that there are at least 100,000 times as many galaxies as theorists predicted at redshifts more than 10. There is no way that so many large galaxies can be generated in so little time, so again-- no Big Bang.
While Big Bang theorists were shocked and panicked by these new results, Riccardo and I (and a few others) were not. In fact, a week before the JWST images were released we published online a paper that detailed accurately what the images would show. We could do this with confidence because more and more data of all kinds has been contradicting the Big Bang hypothesis for years. The widely-publicized crisis in cosmology has drawn general attention to the failed predictions of the Big Bang hypothesis for the Hubble constant relating redshift to distance. But our papers, published over the past decades, have pointed to far more contradictions, each individually acknowledged by other researchers.
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Based on the published literature, right now the Big Bang makes 16 wrong predictions and only one right one—the abundance of deuterium, an isotope of hydrogen.
___ The Big Bang prediction of the abundance of helium is off by a factor of two, the prediction for the abundance of lithium is off by a factor of 20. In addition to the absence of the larger-more-distant optical illusion, there is also the existence of large-scale structures too big to have formed in the times since the Big Bang, wrong predictions for the density of matter in the universe, and well-known asymmetries in the cosmic microwave background that should not exist according to theory. There are many more contradictions. In early July I published two comprehensive papers summarizing the situation. Based on the published literature, right now the Big Bang makes 16 wrong predictions and only one right one—the abundance of deuterium, an isotope of hydrogen. SUGGESTED READING Cosmology in crisis By BjørnEkeberg Readers may well be wondering at this point why they have not read of this collapse of the Big Bang hypothesis in major media outlets by now and why the authors of so many recent papers have not pointed to this collapse themselves. The answer lies in what I term the “Emperor’s New Clothes Effect”—if anyone questions the Big Bang, they are labeled stupid and unfit for their jobs. Unfortunately, funding for cosmology comes from a very few government sources controlled by a handful of committees that are dominated by Big Bang theorists. These theorists have spent their lives building the Big Bang theory. Those who openly question the theory simply don’t get funded.
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It has now become almost impossible to publish papers critical of the Big Bang in any astronomical journals.
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Until the past few years, if researchers could self-fund cosmology research as a sideline, as is the case with me, they still could publish “heretical” papers, although those papers were often ignored by the cosmological establishment. As recently as 2018, the Monthly Notices of the Royal Astronomical Society (MNRAS), a leading journal, published one of my papers showing how the sizes of galaxies contradicted the expanding universe idea.
But as the crisis in cosmology became obvious in 2019, the cosmological establishment has circled the wagons to protect this failed theory with censorship, because it now has no other defense. It has now become almost impossible to publish papers critical of the Big Bang in any astronomical journals. An anonymous senior editor rejected my survey papers, writing “There are many journals which would be interested in publishing a well-argued synthesis of existing evidence against the standard hot big bang interpretation. But MNRAS, with its focus on publication of significant new astronomical results, is not one of them”. The replies from several other journals were similar.
Such censorship is now, as always, inimical to the progress of science. Two dozen researchers in astrophysics, astronomy and space science have signed a letter of protest to the arXiv leadership. I have personally called on leading Big Bang theorists to openly debate the new evidence. For cosmology – as for any research area - to advance, this debate must happen openly in both scientific journals and the public media.
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To use fusion energy, the power that drives the universe and gives light to the Sun and all the stars, we need to understand the processes that drive cosmic evolution.
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These scientific questions matter in the here and now. Over decades scientists, starting with Physics Nobel Laureate Hannes Alfven, have shown that if the Big Bang hypothesis is thrown out, the evolution of the cosmos and the phenomena that we observe today, like the cosmic microwave background, can be explained using the physical processes we observe in the laboratory—especially the electromagnetic processes of plasmas. Plasma is the electrically conducting gas that makes up nearly all the matter that we see in space, in the stars and in the space between the stars. Only the Hubble redshift relation would still need some new physical process to explain the loss of energy as light travels huge distances.
One of the key processes in plasmas that Alfven and his colleagues identified, and which has been studied for 50 years, is plasma filamentation. This is the process by which electric currents, and the magnetic fields they create, draw plasma into the lacy system of filaments that we see at all scales in the universe from the aurorae in the earth’s atmosphere to the solar corona to galactic spiral arms, even to clusters of galaxies. Together with gravitational forces, plasma filamentation is one of the basic processes in the formation of planets, stars, galaxies and structures at all scales.
That process of plasma filamentation is also key to the enormously important effort to develop fusion energy here on earth. To use fusion energy, the power that drives the universe and gives light to the Sun and all the stars, we need to understand the processes that drive cosmic evolution. Just as the Wright Brothers developed the airplane by studying how birds controlled their flight, so today we can only control the ultra-hot plasma where fusion reactions occur by studying how plasmas behave at all scales in cosmos. We need to imitate nature, not try to fight it. We at LPPFusion have been applying that knowledge concretely to the development of a cheap, clean and unlimited source of energy that can entirely replace fossil fuels starting in this decade.
While many researchers have been funded to study these processes on the scale of the sun and the solar system, work on larger scales has been hobbled by the straightjacket of the Big Bang hypothesis, which has diverted hundreds or thousands of talented researchers into futile calculations of the imaginary entities, like dark matter and dark energy, that have been invented to prop up a failing theory. Open debate can clear away that failed theory and lead to the reorientation of cosmology to the study of real phenomena, advancing technology here on earth. It is time to end the censorship and to let the debate begin. Cosmology can emerge from its crisis once it is recognized that the Big Bang never happened.
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Cosmology & The Universe
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Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. CNN — In early human history, caves provided people with protection from the elements and a place to call home. Now, similar formations on the moon could provide pioneering astronauts with a lunar safe haven, thanks to their Earth-like temperatures. The moon has pits with shaded areas that steadily hover around 63 degrees Fahrenheit (17 degrees Celsius), a temperate range that’s stable for humans, found researchers at the University of California, Los Angeles. The journal Geophysical Research Letters published the study in July. These pit craters, which may potentially lead to caves that could also provide human shelter, have temperatures that could make lunar exploration and long-term human habitation on the moon safer, as scientists would be able to set up thermally stable base camps. “Humans evolved living in caves, and to caves we might return when we live on the moon,” said study coauthor David Paige, professor of planetary science at UCLA, in a news release. Paige also leads the Diviner Lunar Radiometer Experiment, an instrument on NASA’s Lunar Reconnaissance Orbiter. Now that there is a better understanding of the pits and potential caves, scientists could possibly pick up the pace toward conceptualizing a workable permanent station, protected from the extreme conditions of the moon’s surface. “We could be able to establish a long-term presence on the moon sooner than may have otherwise been possible,” said lead study author Tyler Horvath, a doctoral student in planetary science at UCLA. Unlike the moon’s surface, which heats up to 260 degrees Fahrenheit (127 degrees Celsius) during the day and drops to minus 280 degrees Fahrenheit (minus 173 degrees Celsius) at night, these lunar pits in the Mare Tranquillitatis region have a human-friendly, stable temperature. (Mare Tranquillitatis, commonly known as the Sea of Tranquility, is where Apollo 11, the first mission to put humans on the moon, landed due to its smooth and relatively flat terrain.) The data comes from an analysis of images taken by NASA’s Lunar Reconnaissance Orbiter spacecraft and computer modeling. “These (pits) are right at the resolution limit of the cameras that they’re trying to use,” said Briony Horgan, associate professor of Earth, atmospheric and planetary sciences at Purdue University in West Lafayette, Indiana. “The fact that they are able to pull that data out and show that it was pretty convincing, I think it’s a big step forward in looking at the moon.” Learning about these pits and probable caves helps scientists better understand how other extreme environments behave, such as the lunar polar regions where the Artemis mission is going, said Noah Petro, chief of NASA’s Planetary Geology, Geophysics and Geochemistry Lab. The NASA Artemis program aims to return humans to the moon and land the first woman and first person of color on the lunar surface by 2025. “Artemis has the goal of sending humans to the region around the South Pole, where we know there are some very cold places,” said Petro via email. “Fortunately, we have a large amount of data for the south pole region where Artemis will visit.” The extreme temperatures of the moon’s surface have made it difficult for NASA to create fully operational heating and cooling equipment that would produce enough power to allow for longer-term lunar exploration or habitation, according to the news release. However, NASA may not need equipment as complex as currently assumed to make exploration and habitation a reality, this research has shown. With the help of the lunar orbiter, scientists discovered pits on the moon in 2009, a finding that prompted scientists to wonder if there were connecting caves that could be explored or even used as shelters. “About 16 of the more than 200 pits are probably collapsed lava tubes,” Horvath said in the news release. When a lava tube – a long, hollow tunnel and cavelike structure formed by lava – collapses, it opens a pit that can create an entrance to the rest of the cave. There are at least two, likely three, pits that have overhangs that lead to caves, the release said. Caves would be a stable environment for lunar habitats since they offer some protection from solar radiation and micrometeorite impacts, Horgan said. These formations could also provide a measure of protection against cosmic rays, according to NASA. It would be helpful to build on the current research with radar data to find additional potential caves, Horgan added. The research “gives engineers who are really thinking about how to design a habitat on the moon real numbers to work with,” she said. “That’ll be incredibly important going forward.” Currently, NASA has plans for robotic exploration on the moon through its Commercial Lunar Payload Services program. Starting in December 2022, cargo flights will deliver devices that navigate and map the lunar surface, conduct investigations, measure radiation levels and assess how human activity impacts the moon. These flights give scientists the ability to reach anywhere on the lunar surface, including Mare Tranquillitatis, Petro said. “Continuing to map the temperature of the lunar surface is a high priority for LRO, as we’ll be able to use that information not only to better understand the environment future missions to the surface will experience,” Petro said, “but we can also learn about how different types of surface material respond to the changing lighting conditions at the lunar surface.”
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Cosmology & The Universe
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Scientists have made one of the most precise maps of the universe's matter, and it shows that something may be missing in our best model of the cosmos.
Created by pooling data from two telescopes that observe different types of light, the new map revealed that the universe is less "clumpy" than previous models predicted — a potential sign that the vast cosmic web that connects galaxies is less understood than scientists thought.
According to our current understanding, the cosmic web is a gigantic network of crisscrossing celestial superhighways paved with hydrogen gas and dark matter. Taking shape in the chaotic aftermath of the Big Bang, the web's tendrils formed as clumps from the roiling broth of the young universe; where multiple strands of the web intersected, galaxies eventually formed. But the new map, published Jan. 31 as three (opens in new tab) separate (opens in new tab) studies (opens in new tab) in the journal Physical Review D, shows that in many parts of the universe, matter is less clumped together and more evenly spread out than theory predicts it should be.
"It seems like there are slightly less fluctuations in the current universe than we would predict assuming our standard cosmological model anchored to the early universe," co-author Eric Baxter, an astrophysicist at the University of Hawaii, said in a statement (opens in new tab).
Spinning the cosmic web
According to the standard model of cosmology, the universe began taking shape after the Big Bang, when the young cosmos swarmed with particles of both matter and antimatter, which popped into existence only to annihilate each other upon contact. Most of the universe's building blocks wiped themselves out this way, but the rapidly expanding fabric of space-time, along with some quantum fluctuations, meant that some pockets of the primordial plasma survived here and there.
The force of gravity soon compressed these plasma pockets in on themselves, heating the matter as it was squeezed closer together to such an extent that sound waves traveling at half the speed of light (called baryon acoustic oscillations) rippled outward from the plasma clumps. These ripples pushed away the matter that hadn't already been drawn into the center of a clump, where it came to rest as a halo around it. At that point, most of the universe's matter was distributed as a series of thin films surrounding countless cosmic voids, like a nest of soap bubbles in a sink.
Once this matter, primarily hydrogen and helium, had sufficiently cooled, it clotted further to birth the first stars, which, in turn, forged heavier and heavier elements through nuclear fusion.
To map out how the cosmic web was spun, the researchers combined observations taken with the Dark Energy Survey in Chile — which scanned the sky in the near-ultraviolet, visible and near-infrared frequencies from 2013 to 2019 — and the South Pole Telescope, which is located in Antarctica and studies the microwave emissions that make up the cosmic microwave background — the oldest light in the universe.
Though they look at different wavelengths of light, both telescopes use a technique called gravitational lensing to map the clumping of matter. Gravitational lensing occurs when a massive object sits between our telescopes and its source; the more that light coming from a given pocket of space appears warped, the more matter there is in that space. This makes gravitational lensing an excellent tool for tracking both normal matter and its mysterious cousin dark matter, which, despite making up 85% of the universe, doesn't interact with light except by distorting it with gravity.
With this approach, the researchers used data from both telescopes to pinpoint the location of matter and weed out errors from one telescope's data set by comparing it to the other's.
"It functions like a cross-check, so it becomes a much more robust measurement than if you just used one or the other," co-lead author Chihway Chang (opens in new tab), an astrophysicist at the University of Chicago, said in the statement.
The cosmic matter map the researchers produced closely fitted our understanding of how the universe evolved, except for a key discrepancy: It was more evenly distributed and less clumped than the standard model of cosmology would suggest.
Two possibilities exist to explain this discrepancy. The first is that we're simply looking at the universe too imprecisely, and that the apparent deviation from the model will disappear as we get better tools to peer at the cosmos with. The second, and more significant, possibility is that our cosmological model is missing some seriously big physics. Finding out which one is true will take more cross-surveys and mappings, as well as a deeper understanding of the cosmological constraints that bind the universe's soap suds.
"There is no known physical explanation for this discrepancy," the researchers wrote in one of the studies. "Cross-correlations between surveys … will enable significantly more powerful cross-correlation studies that will deliver some of the most precise and accurate cosmological constraints, and that will allow us to continue stress-testing the [standard cosmological] model."
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Cosmology & The Universe
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When it comes to the biggest questions about the cosmos, physicists tend to either shy away from them or assert theories that have no real empirical backing. The Big Bang is a good example – a creation myth that physics will probably never be able to show is true. But these theories are also not simply equivalent to religious dogma, they lie in the undefined space between science and religion – not in conflict with science, but not supported by it either, argues Sabine Hossenfelder. Many people have a bad start with physics in school. I did, too. Physics seemed all about magnets and atoms and balls rolling down inclined planes. I didn’t find it particularly engaging. And yet, today, I’m a physicist.In school, we see only one side of physics, but it has another side. Physics is one of the best ways to make sense of our own existence: Does the past still exist? Do copies of us live in other universes? Can information be destroyed? Does science have limits? Those are some examples of questions that physics helps us answer.___That most physicists keep quiet about those big questions has another downside: it leaves the arena to those who conflate religion with science___Physicists don’t like to talk about this existential side of their research. I suspect that’s because, historically, existential questions have been the realm of religion, and scientists want to keep their distance. But keeping this distance has a downside: it also distances science from humanity. It’s probably part of the reason that scientists in general, and physicists in particular, are perceived as cold and technocratic. It seems that physicists don’t care about what the fundamental laws of nature imply for people. That most physicists keep quiet about those big questions has another downside: it leaves the arena to those who conflate religion with science. One case where science crosses over into religion is the beginning of our universe. Physicists have put forward many theories for it: a big bang, a big bounce, a collision of higher-dimensional membranes, a gas of strings, a network, a 5-dimensional black hole, and many more – I’ve lost track. But the scientifically correct answer is, rather boringly, that we don’t know how the universe began. Indeed, there are good reasons to think we will never know. But some physicists are unwilling to accept this answer. They fill their knowledge gap with creation myths, written in the language of mathematics. SUGGESTED READING Physics forgets we are part of reality By JenannIsmael These creation myths are not wrong, so it is not unscientific to believe in them. It’s rather that we cannot tell them apart with observations – not now, and quite possibly never. My friend and colleague Tim Palmer from the University of Oxford suggested to call such ideas “ascientific”: Science can’t tell us whether they’re wrong or right. Like the hypothesis of an unobservable, omniscient God, the ideas that our universe emerged from a black hole, or a collision of higher dimensional membranes, or a network, are ascientific.___Believing in the existence in unobservable universes is not in conflict with science; it’s not unscientific. Rather, it’s ascientific___I don’t mean to say that our theory of the cosmos has already reached its endpoint. We will almost certainly improve the current one some more. For example, the new Webb telescope is gathering data that can tell us how galaxies formed. Galaxies are expected to form slowly and gradually if the hypothetical dark matter exists. The competing theory is that dark matter is absent, but gravity does not work as Einstein said it does, an idea known as modified gravity. If the latter is correct, galaxies would form much faster. The Webb telescope can help us tell apart the one hypothesis from the other. However, galaxy formation happened some hundred thousand years after the universe was born, so the Webb telescope will not solve the riddle of its origin for us. Eventually, collecting data and refining our theories will reach a limit. After this, we will have to pick one story on grounds other than scientific evidence. The idea that there are other universes besides our own in a big “multiverse” is another ascientific idea that has taken foothold in physics. Some of those universes contain copies of our solar system, with a human civilization like our own. Indeed, they contain copies of all of us, though those copies might be living their lives in slightly different ways. Not just in one way, but in any possible way. SUGGESTED VIEWING The universe, fixity and flux With Lee Smolin, Sabine Hossenfelder, Paul Davies, Phillip Ball Unlike in the movies, however, the universes that physicists conjecture up can’t be visited. They are entirely unobservable. It’s not just that we can’t see them with our own eyes, there is no observation that could possibly confirm their presence, not even in principle. Why, then, do physicists believe in them? Because they have equations for those other universes, and they believe that mathematics is reason enough to believe that what math describes exists.___In some cases, physics has brought up questions that we might not otherwise even have thought of___Again, believing in the existence in unobservable universes is not in conflict with science; it’s not unscientific. Rather, it’s ascientific. The same is the case for believing they do not exist. Science just doesn’t say anything about their existence, one way or the other. So, do other universes exist? We don’t know.Once I started thinking about it, I realized that physics opens our mind to many ascientific ideas that we can neither refute nor confirm. For example, the idea that the universe as a whole can think. It’s not that we have evidence for it. But it’s compatible with all we know, and we don’t have evidence against it either. Or take the idea that one day we might be able to upload ourselves to a computer, or create a universe. I can’t tell you it’s going to happen, but it’s not in conflict with what we know about the laws of nature. It’s not unscientific to believe it. It’s just ascientific. In some cases, physics has brought up questions that we might not otherwise even have thought of. Einstein’s theory of space and time, for example, makes it impossible to pin down any moment in time as special. For all we currently know, our experience of time as passing is an artefact of our perception, not a fundamental property of nature. Without scrutinizing the math and the evidence for it, we might not have thought of this, exactly because it contradicts our experience. SUGGESTED READING Physics needs an aesthetic revolution By MarceloGleiser Another existential question in the realm of physics is whether information can get lost. It’s why physicists are obsessed with the black hole information loss paradox: because it seems that throwing information into a black hole might be the only way to forever destroy information. On this, the jury is still out–physicists don’t agree on the answer, but most of them (me included) currently think black holes probably quite possibly can’t be destroyed. When we try to answer the big questions of our existence, we have three options: Science, philosophy, and physics. Of those three, physics has made the most progress in the past century, and we yet have to fully understand what it all means. Yes, physics is the subject that deals with magnets and atoms and balls rolling down inclined planes. But it’s also so much more than this.
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Cosmology & The Universe
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Lifes-little-mysteries In this illustration, the supermassive black hole at the center is surrounded by matter flowing onto the black hole in what is termed an accretion disk.
(Image credit: NASA/JPL-Caltech) Black holes are cosmic vacuum cleaners — massive objects so large that not even light can escape them. Most people imagine black holes do nothing but sit there and devour wandering pieces of gas or dust. But could black holes actually have more interesting interior lives? Could they, for instance, explode? If an "explosion" is "a sudden, brief release of tremendous amounts of energy" then the answer is unequivocally yes. And the best part is that they can explode in several interesting ways, either by detonating themselves or their nearby environments.Hawking radiationThere is one way in which black holes can explode. The process behind this is related to the fact that black holes aren't entirely black, which was discovered by famed astrophysicist Stephen Hawking in 1976."In classical physics, nothing can come out of the hole," Samir Mathur, a physicist at The Ohio State University, told Live Science in an email. "But Hawking found that with quantum mechanics, the hole slowly leaks away its energy to infinity by emitting low energy radiation; this is called Hawking radiation."Related: Are black holes wormholes?As long as a black hole isn't sucking in new material, it will slowly lose mass as it emits Hawking radiation. However, Hawking radiation is emitted slowly. A normal black hole with a mass a few times that of the sun emits approximately one photon, or packet of light, every year. At that rate, the typical black hole would take 10^100 years to completely evaporate.But Hawking realized that smaller black holes evaporate much more quickly. As a black hole gets smaller and smaller, it emits more and more radiation. In the last moments of its life, the black hole emits so much radiation, so quickly that it effectively acts like a bomb, releasing a torrent of high-energy radiation and particles.If small black holes (about the size of Earth) formed in the extremely early universe, they would take a few billion years to evaporate, meaning that these "primordial" black holes, if they exist, would be exploding all over the universe right now.To date astronomers have not found any evidence of exploding primordial black holes, but they could be out there.SuperradianceBlack holes go bang with another type of explosion found nowhere else in the universe, thanks to the fact that they spin. Rotating black holes — also named Kerr black holes in honor of New Zealand mathematician Roy Kerr, who first figured out how they work — create an ergosphere around their event horizons. An ergosphere is an elongated region of space where nothing can stay still. Anything that falls toward the spinning black hole begins to orbit around it as the particle enters the ergosphere.The rotating space-time around a black hole can also pull on photons. If there are enough photons, they can bounce off of each other or any wandering particles. Sometimes the bouncing causes the photons to escape the ergosphere. But other times the bouncing causes the photons to fall deeper towards the black hole, where they gain energy. They can then get scattered to a higher orbit again, then fall back down.With every repeat of the process, and every trip around the black hole, the photon gains energy. This process is called "superradiance." If the photon finally breaks free, it will have an enormous amount of energy compared with when it first started its journey.If enough photons participate in the process, they can all come bursting out at once with incredible energy, becoming what's known as a "black hole bomb." Even though the black hole itself doesn't explode, this superradiant effect once again shows just how powerfully black holes can affect their environment.Disks and jetsThis image is an artist's concept of a tidal disruption event that happens when a star passes fatally close to a supermassive black hole, which reacts by launching a relativistic jet. (Image credit: Sophia Dagnello, NRAO/AUI/NSF)The most common way that black holes cause explosions is not through their own self-destruction, but through the sheer power of their overwhelming gravitational force. Supermassive black holes sit in the centers of galaxies, and sometimes large clumps of matter, such as stars, pass too close. When that happens, the star gets torn to shreds from tidal effects, and this tearing process releases an explosive burst of energy. Astronomers on Earth can witness this release of energy as a brief but intense flare of X-ray and gamma-ray radiation.Besides shredding up stars, these giant black holes frequently collect swarms of matter that constantly swirl around them in giant accretion disks. The accretion disks reach temperatures of quadrillions of degrees, making them the brightest objects in the universe — a single glowing disk can outshine over a million galaxies at once.At their most powerful, the disks wind up electric and magnetic fields that funnel some of the disk material around the black holes and out in the form of long, thin jets that reach for tens of thousands of light-years.While these jets don't technically count as explosions, they're still pretty intense.Originally published on Live Science. Paul M. Sutter is a research professor in astrophysics at SUNY Stony Brook University and the Flatiron Institute in New York City. He regularly appears on TV and podcasts, including "Ask a Spaceman." He is the author of two books, "Your Place in the Universe" and "How to Die in Space," and is a regular contributor to Space.com, Live Science, and more. Paul received his PhD in Physics from the University of Illinois at Urbana-Champaign in 2011, and spent three years at the Paris Institute of Astrophysics, followed by a research fellowship in Trieste, Italy.
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Cosmology & The Universe
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Astronomers have detected a strange and persistent "heartbeat" radio signal coming from a far-off galaxy.It has been classified as a fast radio burst (FRB), but where such signals are normally intensely strong emissions of radio waves of unknown origin - that typically last a few milliseconds at most - this one is different.
The new signal - which appears to flash in a pattern similar to a beating heart - runs for up to three seconds, about 1,000 times longer than an average FRB.News of the discovery emerges in the same week that incredible images of a dying star and a 'cosmic dance' were revealed in an extraordinary set of NASA photos.The team detected bursts of radio waves that repeat every 0.2 seconds within this window, in a clear periodic pattern. Researchers say there are very few things in the universe known to emit these strictly periodic signals.
Daniele Michilli, a postdoc at the Massachusetts Institute of Technology (MIT) Kavli Institute for Astrophysics and Space Research, explained: "Examples that we know of in our own galaxy are radio pulsars and magnetars, which rotate and produce a beamed emission similar to a lighthouse. More on Space A dying star and a 'cosmic dance': Ancient galaxies revealed in never-seen-before telescope pictures NASA reveals picture of distant universe taken by James Webb Space Telescope - but why is it a big deal? Astronauts suffer 'significant' bone loss during space missions - raising concerns for future trips to Mars "And we think this new signal could be a magnetar or pulsar on steroids."Radio pulsars and magnetars are types of neutron star - extremely dense, rapidly spinning collapsed cores of giant stars.Called FRB 20191221A, the signal is currently the longest-lasting FRB, with the clearest periodic pattern, detected to date.Its source lies in a distant galaxy, several billion light-years from Earth.The team hopes to detect more periodic signals from this source, which could then be used as an astrophysical clock.
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Cosmology & The Universe
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Ultra-relativistic neutrinos blasted into space during gamma-ray bursts are slowed down by the effects of quantum gravity. That is the conclusion of physicists in Italy, Poland and Norway, who have spotted seven neutrinos that arrived on Earth later than expected, compared to their companion gamma rays.
Quantum theory does a fantastic job of describing interactions that involve three out of the four known forces of nature. However, there is no theory today that adequately describes the quantum nature of gravity. While theories of quantum gravity have been proposed, they tend to make predictions that cannot currently be tested by experiment or observation.
One prediction that physicists have a chance of confirming today is that particles moving very near to the speed of light will lose energy because of a quantum gravitational effect. The faster the particle is moving, the more the effect is enhanced. While the effect is extremely small, if the particles are created in an astrophysical event billions of light-years away, the cumulative result would be a delay that could be measured when the particles arrive on Earth.
Late neutrinos
Now, a team led by Giovanni Amelino-Camelia of the University of Naples have looked for this effect in neutrino data collected by the IceCube Neutrino Observatory. Located at the South Pole, the observatory detects neutrinos when they occasionally interact within a cubic kilometre of ice.
The researchers identified seven neutrinos that have high probabilities of coming from gamma-ray bursts. These are highly energetic events that are produced either by the supernovae of the most massive stars, or by colliding neutron stars. Gamma rays from these specific bursts were also detected by NASA’s Fermi Gamma-ray Space Telescope.
Tantalizingly, these neutrinos appear to have arrived at Earth up to three days after the gamma rays were detected, suggesting that something had delayed them. The three-day delay is expected of particles with energies up to 500 TeV. In comparison, neutrinos with higher energies up to 2 PeV would require a 12-day delay window, which is too long to positively identify them with a specific gamma-ray burst.
Amelino-Camelia explains: “The particles get this extra contribution to their speed, which is negative, and it grows in magnitude as their energy grows”.
Location, location
However, not everyone is convinced. Teppei Katori of Kings College London, who was not involved in the work, points out that the seven candidate neutrinos are all of the “cascade-type”. In a cascade event, a neutrino enters the IceCube Observatory and deposits all of its energy into a small, spherical region, making it difficult to determine the direction that the neutrino came from. This is unlike a “track event”, which produces a signal that points back to the neutrino’s point of origin in the cosmos.
“We don’t know where these neutrinos are coming from exactly,” explains Katori.
Indeed, it is not even clear that gamma-ray bursts do produce a significant number of neutrinos. Katori cites earlier work describing a search for neutrinos from gamma-ray bursts that failed to find a correlation between the two. However, he accepts that this search did not take into account any delays caused by quantum-gravity effects.
In 2022 Katori – who is part of the IceCube collaboration – was a science lead on another experiment looking for quantum gravity effects in neutrinos. Specifically, this study looked at how quantum gravity could affect neutrino oscillations.
Neutrinos come in three different “flavours” – electron, muon and tau – and the particles can oscillate from one flavour to another. Although the experiment found no evidence for quantum gravity affecting neutrino oscillations, it was the first experiment to probe these oscillations at a level where quantum gravity should be relevant. As such, the experiment was able to impose constraints on quantum-gravity models that predict variations in the oscillations.
Implications for cosmology
If quantum gravity is indeed slowing down neutrinos, both Amelino-Camelia and Katori agree that the observation would be a major step forward in understanding quantum gravity and its role in the evolution of the universe.
However, Amelino-Camelia points out, “If the effect is only there for neutrinos and other half-integer spin particles, then the implications for cosmology might be minor.”
Quantum gravity could soon be tested using ultracold atoms
For Katori, the most significant outcome of confirming a delay is that physicists could use it to calculate the size of the quantum gravity effect. This would allow physicists to evaluate competing models of quantum gravity – and to take the next step and design experiments and observatories to measure the effect more precisely.
“There is still a gap between quantum-gravity-motivated phenomenology models and quantum-gravity theories,” says Katori. “I think filling this gap is challenging [but] finding any quantum-gravity-motivated effect is the first step.”
The search for neutrinos from gamma-ray bursts will benefit from the construction of IceCube-Gen2, which will increase the size of the detector volume to eight cubic kilometres of ice, improving the ability of the observatory to pinpoint the origins of neutrinos.
The research is described in Nature Astronomy.
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Cosmology & The Universe
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A cluster of young stars resembles an aerial burst, surrounded by clouds of interstellar gas and dust, in a nebula NGC 3603 located in the constellation Carina, in this image captured in August 2009 and December 2009, and obtained September 26, 2018. NASA/ESA/R. O'Connell/F. Paresce/E. Young/Ames Research Center/WFC3 Science Oversight Committee/Hubble Heritage Team/STScI/AURA/Handout via REUTERS Register now for FREE unlimited access to Reuters.comJuly 10 (Reuters) - Drawing back the curtain to a photo gallery unlike any other, NASA will soon present the first full-color images from its James Webb Space Telescope, a revolutionary apparatus designed to peer through the cosmos to the dawn of the universe.The highly anticipated July 12 unveiling of pictures and spectroscopic data from the newly operational observatory follows a six-month process of remotely unfurling various components, aligning its mirrors and calibrating instruments.With Webb now finely tuned and fully focused, astronomers will embark on a competitively selected list of science projects exploring the evolution of galaxies, the life cycles of stars, the atmospheres of distant exoplanets and the moons of our outer solar system.Register now for FREE unlimited access to Reuters.comThe first batch of photos, which have taken weeks to process from raw telescope data, are expected to offer a compelling glimpse at what Webb will capture on the science missions that lie ahead.NASA on Friday posted a list of the five celestial subjects chosen for its showcase debut of Webb, built for the U.S. space agency by aerospace giant Northrop Grumman Corp (NOC.N).Among them are two nebulae - enormous clouds of gas and dust blasted into space by stellar explosions that form nurseries for new stars - and two sets of galaxy clusters.One of those, according to NASA, features objects in the foreground so massive that they act as "gravitational lenses," a visual distortion of space that greatly magnifies the light coming from behind them to expose even fainter objects farther away and further back in time. How far back and what showed up on camera remains to be seen.NASA will also publish Webb's first spectrographic analysis of an exoplanet, revealing the molecular signatures from patterns of filtered light passing through its atmosphere. The exoplanet in this case, roughly half the mass of Jupiter, is more than 1,100 light years away. A light year is the distance light travels in a year - 5.9 trillion miles (9.5 trillion km).'MOVED ME AS A SCIENTIST ... AS A HUMAN BEING'All five of the Webb's introductory targets were previously known to scientists. One of them, the galaxy group 290 million light-years from Earth known as Stephan's Quintet, was first discovered in 1877.But NASA officials promise Webb's imagery captures its subjects in an entirely new light, literally."What I have seen moved me as a scientist, as an engineer and as a human being," NASA deputy administrator Pam Melroy, who has reviewed the images, told reporters during a June 29 news briefing.Klaus Pontoppidan, a Webb project scientist at the Space Telescope Science Institute in Baltimore, where mission control engineers operate the telescope, has promised the first pictures would "deliver a long-awaited 'wow' for astronomers and the public."The $9 billion infrared telescope, the largest and most complex astronomical observatory ever sent to space, was launched on Christmas Day from French Guiana, on the northeastern coast of South America.A month later, the 14,000-pound (6,350-kg) instrument reached its gravitational parking spot in solar orbit, circling the sun in tandem with Earth nearly 1 million miles from home. read more Webb, which views its subjects chiefly in the infrared spectrum, is about 100 times more sensitive than its 30-year-old predecessor, the Hubble Space Telescope, which orbits Earth from 340 miles (547 km) away and operates mainly at optical and ultraviolet wavelengths.The larger light-collecting surface of Webb's primary mirror - an array of 18 hexagonal segments of gold-coated beryllium metal - enables it to observe objects at greater distances, thus further back in time, than Hubble or any other telescope.Its infrared sensitivity allows it to detect light sources that would otherwise be hidden in the visible spectrum by dust and gas.Taken together, these features are expected to transform astronomy, providing the first glimpse of infant galaxies dating to just 100 million years after the Big Bang, the theoretical flashpoint that set the expansion of the known universe in motion an estimated 13.8 billion years ago.Webb's instruments also make it ideal to search for signs of potentially life-supporting atmospheres around scores of newly documented plants orbiting distant stars and to observe worlds much closer to home, such as Mars and Saturn's icy moon Titan.Besides a host of studies already lined up for Webb, the telescope's most revolutionary findings may prove to be those that have yet to be anticipated.Such was the case in Hubble's surprising discovery, through observations of distant supernovas, that the expansion of the universe is accelerating, rather than slowing down, opening a new field of astrophysics devoted to a mysterious phenomenon scientists call dark energy.The Webb telescope is an international collaboration led by NASA in partnership with the European and Canadian space agencies.Register now for FREE unlimited access to Reuters.comReporting and writing by Steve Gorman; Additional reporting by Joey Roulette; Editing by Lisa ShumakerOur Standards: The Thomson Reuters Trust Principles.
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Cosmology & The Universe
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