Latest news with #PopIII
Yahoo
14-03-2025
- Science
- Yahoo
Water Formed Much Sooner After the Big Bang Than We Thought, Scientists Say—Which May Mean Life Did, Too
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." It is now thought that water first formed in space only 100 to 200 million years after the Big Bang—billions of years earlier than previous estimates. Simulations showed that oxygen created by primordial stars first fused with hydrogen in space when those stars exploded into supernovae. Planets that emerged from the molecular clouds left behind by those early supernovae might have had habitable conditions because of the presence of water in those clouds. Life (at least as we know it) requires water. Maybe there are life-forms out there that can survive without it, but so far, nobody knows what may be creeping around on distant exoplanets. So, as far as we know for sure, that first statement stands. And because of that, the earlier water appeared in space, the earlier life could have hypothetically crawled out of somewhere. Now, a team of researchers—led by astrophysicist Daniel Whalen of the University of Portsmouth in England—has found that the first molecules of water may have formed billions of years before we thought they did. By running simulations of the early universe, Whalen showed that water could have been created by nuclear fusion in the cores of the oldest dying stars only 100 to 200 million years after the Big Bang. Few elements survived the intensity of the Big Bang. The lighter elements that did make it were hydrogen (one component of water), helium, lithium, and scant traces of barium and boron. Water, then, actually came from stars. Population III stars—also known as Pop III stars or primordial stars—are the oldest stars in the universe, and have still eluded even our most powerful telescopes. Before they burned themselves out and exploded into supernovae, there was no oxygen in the universe. And water cannot exist without oxygen. 'Primordial supernovae were the first nucleosynthetic engines in the universe, and they forged the heavy elements required for the later formation of planets and life,' Whalen and his team said in a study recently published in the journal Nature Astronomy. While even the supernovae of Pop III stars are so ancient that none have been detected, simulations of two possible types of primordial supernovae (core-collapse and pair-instability supernovae) showed how water was likely synthesized in the nascent universe. After massive stars (over 10 solar masses) have fused all their hydrogen nuclei in their cores into helium, fused their helium into heavier elements, and fused some of those into even heavier elements, they explode into supernovae. Both core-collapse and pair-instability supernovae eject heavier elements, including oxygen, into space (though, a pair-instability supernova produces much higher amounts of those elements). Whalen's simulations showed that huge molecular clouds formed in the supernova aftermath. As these clouds expanded and then cooled, oxygen in the haloes of the clouds reacted with hydrogen to create water. Later, much more water formed in the clouds' dense core. Stars and planets are thought to be born in protoplanetary disks that take shape in the superdense gas of molecular cloud cores, which means it is possible that the water present in those clouds might have given some early planets habitable conditions. That said, there are, of course, many other factors that determine habitability. How the earliest planets were affected by cosmic radiation and other factors remains unknown. '[Water was] highly concentrated in the only structures capable of forming stars and planets,' Whalen said in a press release. 'And that suggests that planetary disks rich in water could form at cosmic dawn, before even the first galaxies.' If water finds a way, maybe life does, too. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Yahoo
07-03-2025
- Science
- Yahoo
We May Have Finally Laid Eyes on The Universe's Very First Stars
Once, there was a time before stars. In the primordial darkness, after the Big Bang, nothing drifted but a vast sea of hydrogen and helium. It wasn't until stars came along, born from crushing densities in that clumping gas, that heavier elements emerged, forged by the fusion in their powerful hearts. Or so scientists believe. We've never actually seen those first stars, known as Population III stars. A new paper may finally change that. In a preprint submitted to The Astrophysical Journal and uploaded to arXiv, a large international team of astronomers led by Seiji Fujimoto of the University of Texas at Austin has described what they think might be a galaxy in the early Universe rich in these elusive objects. This galaxy, called GLIMPSE-16403, is by no means confirmed as a Population III host. But the identification of even a candidate suggests that it's only a matter of time before we finally locate the first stars in the Universe. "This work paves a clear path for the discovery of the first Pop III galaxies," the researchers write. "Whatever the fate of the present candidates, the methods developed in this study will empower Pop III galaxy searches throughout the JWST era." The Cosmic Dawn is what we call the era that spans the first billion or so years after the Big Bang popped the Universe into existence some 13.8 billion years ago. During this time, the cosmos came together from a hot quark-gluon plasma that filled the Universe in its first moments, forming stars and galaxies that literally swept away the darkness with their blazing light. Those first Population III stars were a vital step towards the Universe we see around us today. Elements heavier than hydrogen and helium can only be created by extreme processes such as core fusion and nova explosions. Yet previous research has only yielded second-hand traces of these first generation stars, not the objects themselves. Astronomers believe that this is because Population III stars may have been particularly massive, larger than any stars around in the more recent Universe. Larger stars live much, much shorter lives than smaller ones, so those first stars may have long flickered out, leaving behind only the elements they fused in their cores to be taken up by subsequent stellar generations. Cosmologists and astronomers desperately want to see what those early stars were like. They want to find out how the lights turned on in the Cosmic Dawn, clearing the neutral hydrogen fog that rendered space opaque. Our best shot for this is JWST, the most powerful space telescope ever built, optimized for peering farther back into the early Universe than any telescope before with its infrared-sensitive eye. Seeing into the Cosmic Dawn is hard enough, but looking for a needle in that particular haystack is even harder. Fujimoto and his colleagues figured they could expedite the search by looking very, very closely at only small regions of the sky, looking for the chemical fingerprints of Population III stars. The researchers focused their efforts on galaxies with powerful hydrogen and helium emission spectra, and little evidence of other elements. Their pipeline yielded two candidates. One was only tentative; but the other, GLIMPSE-16403, hanging out in the Cosmic Dawn around 825 million years after the Big Bang, met all the criteria the researchers had specified for a Population III galaxy. This makes the galaxy the best candidate to date for finding the stars that switched on the lights in the Universe. More work will need to be done to determine the nature of the stars in GLIMPSE-16403, which might be tricky; we'd need a detailed spectrum, and that's not easy to obtain across such vast gulfs of space-time. Nevertheless, the discovery is an incredibly exciting one: the detection of Population III stars now feels like it's right around the next corner. "Exactly a hundred years ago, our cosmic horizon expanded past the edges of the Milky Way for the first time, with Andromeda and Triangulum marking the boundaries of our place in the Universe," the researchers write. "As we reflect on the profound discoveries of the last hundred years, it is intriguing to consider how those early surveyors of glass plates would view the prospect that we may soon detect the Universe's very first stars." The team's paper has been submitted to The Astrophysical Journal, and is available on arXiv. Record Discovery: Impact Crater in Australia's Outback Oldest by a Billion Years Intuitive Machines' Second Lunar Lander Touches Down, But Something Feels Familiar NASA Is Planning to Shut Down Another Piece of Voyager 2
Yahoo
03-03-2025
- Science
- Yahoo
Space breakthrough as study finds 'key ingredient for life' existed billions of years before we first thought
Water, the key ingredient for life, likely formed just after the Big Bang - suggesting it has been around billions of years longer than previously thought. A new study has suggested that water came long before galaxies, 'seeding' the formation of planets – and transforming scientists' understanding of how life began. A team of scientists from the University of Portsmouth have revealed that water already existed in the universe 100 to 200-million years after the Big Bang, the massive explosion that launched space, time and matter 13.8 billion years ago. READ MORE: I took my local non-league side to League Two on Football Manager - now I'm their chairman READ MORE: Scientist's 'reality check' warning as common diet trend might do more harm than good In the first study of its kind, researchers modelled the water in the primordial universe – the extremely hot, dense and chaotic state of the cosmos just after the Big Bang. Their findings suggest that habitable planets could have started forming much sooner than previously thought, thanks to early cosmic explosions. According to the simulations, water molecules began forming shortly after the first supernova explosions, which are known as Population III (Pop III) supernovae. These cosmic events were 'essential' for creating elements like oxygen, which are essential for water, according to the study's leader Dr Daniel Whalen, from the University of Portsmouth's Institute of Cosmology and Gravitation. Dr Whalen said: 'Before the first stars exploded, there was no water in the Universe because there was no oxygen. Only very simple nuclei survived the Big Bang - hydrogen, helium, lithium and trace amounts of barium and boron. Oxygen, forged in the hearts of these supernovae, combined with hydrogen to form water, paving the way for the creation of the essential elements needed for life." The research team studied two types of exploding stars: core-collapse supernovae, which generate some heavy elements, and the more powerful Pop III supernovae, which blast huge amounts of metals into space. They found that both types formed 'dense clumps' of gas enriched with water. Although early supernovae produced only a small amount of water, it was packed into dense gas clouds known as cloud cores, Dr Whelan explains. This is where stars and planets are believed to form. Dr Whalen said: 'The key finding is that primordial supernovae formed water in the Universe that predated the first galaxies. So water was already a key constituent of the first galaxies. This implies the conditions necessary for the formation of life were in place way earlier than we ever imagined - it's a significant step forward in our understanding of the early Universe." He added: 'Although the total water masses were modest, they were highly concentrated in the only structures capable of forming stars and planets. And that suggests that planetary discs rich in water could form at cosmic dawn, before even the first galaxies.' The study, a collaboration between the University of Portsmouth and the United Arab Emirates University. was published in the journal Nature Astronomy.
Yahoo
12-02-2025
- Science
- Yahoo
These Black Holes Are So Ancient They Shouldn't Even Exist
Ancient quasars seen by the James Webb Space Telescope technically shouldn't exist, but one rare type of dark matter could make sense of that. Ultra-self-interacting dark matter are supposedly enormous masses that collapsed in on themselves and created the supermassive black holes in these quasars. Scientists formulated a mathematical model to help explain the mysterious quasars was used to predict the masses and other properties of better known quasars, aiding in understanding the earliest supermassive black holes. Able to see into the far reaches of the universe, the James Webb Space Telescope (JWST) glimpsed quasars so distant and ancient that it took tens of billions of years just for their light to reach Earth. There's just one problem: they aren't supposed to exist. Formed only 800 million years after the Big Bang (a cosmic blink of an eye), the quasars (incredibly luminous objects fueled by supermassive black holes) observed by Webb are from an epoch supposedly too early for supermassive black holes to even form. These active galactic nuclei (AGNs) are at least a billion times more massive than the Sun. How they were able to grow to such masses when the universe was still in its infancy is an enigma, but it might involve dark matter. Led by physicist and doctoral student Grant Roberts, a team of researchers from U.C. Santa Cruz tried using different theories to explain how these monstrous black holes formed. From the collapse of the ever-elusive Pop III stars, the first stars to appear in the void, to galactic mergers, none of these theories fit well enough. Then Roberts proposed that they could have come into being from ultra-self-interacting dark matter. Dark matter has not yet been directly detected. If ultra-self-interacting dark matter (uSIDM) exists, it makes up only a small percentage of all dark matter in the universe. Particles of uSIDM are thought to have strong interactions with each other that cause them to travel towards galactic centers and form gobs of dark matter. These interactions also redistribute the mass in the core so its central density decreases while its size increases. Core expansion then turns into core collapse. Once the core can get no larger, it grows more and more dense until the extreme gravity causes it to collapse. 'If this collapse occurs early enough in the halos' evolution, it can provide seeds for the formation of early [supermassive black holes] of adequate mass and [distance],' Roberts and his team said in a study recently published in the Journal of Cosmology and Astroparticle Physics. The supermassive black holes formed from those seeds would then keep growing from the constant accretion of material, and the gravitational forces of black holes this massive are so strong that they will pull in anything that crosses a certain threshold. The more it consumes, the more energy it emits, and some quasars can shine with the light of hundreds of trillions of Suns. To test if the theory was viable, the researchers created a mathematical model of the formation of uSIDM black holes and compared that model to observations of other quasars that were previously discovered and better understood. When used on the known quasars, the model, which presents the interaction strength of uSIDM particles as dependent on their velocity, succeeded in predicting their masses and other properties. Having these results lends more credibility to the model—and the existence of ultra-self-interacting dark matter. The researchers think it could mean that those hypothetical gobs of uSIDM might actually have formed the earliest supermassive black holes in the nascent universe. 'With the advent of JWST, more extremely [distant] quasars are being discovered,' they said in the same study. 'Combining such measurements with the similarly growing population of [closer] quasars would allow us to place more stringent constraints on the formation and accretion timescales of the seeds.' The possibility of supermassive black holes coming into being from a rare form of dark matter just might have shed a little more light on the darkness that surrounds it. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
