There are spinning stars in space. Some of them collapse into black holes. Along the way, they may generate a lot of heavy elements — including gold.
Gold may be a glittery leftover from a newborn black hole’s messy first meal.
Gold is a heavy element. So is platinum. And uranium. These and many other heavy elements might form when rapidly spinning, massive stars collapse into newly formed black holes. Known as collapsars, these stars get their name from that collapse. And as this last dying stage of their lives take place, layers of gas around them explode. That collapse and explosion leave a disk of material swirling around each new black hole. When that black hole devours the surrounding material, the conditions become just right for gold, platinum and other heavy elements to form, scientists now report.
Explainer: What is a computer model?
“Black holes in these extreme environments are fussy eaters,” says Brian Metzger. He is an astrophysicist at Columbia University in New York City. These black holes can gulp down only so much matter at a time. What they don’t swallow blows off in a wind. This wind has lots of neutrons — subatomic particles having no electric charge. With a lot of them in the wind, it makes just the right conditions for the creation of heavy elements, Metzger says. At least that’s what simulations from his team’s new computer model suggest.
Metzger and his colleagues described those simulations and their results online May 8, 2019 in Nature.
There are spinning stars in space. Some of them collapse into black holes. Along the way, they may generate a lot of heavy elements — including gold.
Gold may be a glittery leftover from a newborn black hole’s messy first meal.
Gold is a heavy element. So is platinum. And uranium. These and many other heavy elements might form when rapidly spinning, massive stars collapse into newly formed black holes. Known as collapsars, these stars get their name from that collapse. And as this last dying stage of their lives take place, layers of gas around them explode. That collapse and explosion leave a disk of material swirling around each new black hole. When that black hole devours the surrounding material, the conditions become just right for gold, platinum and other heavy elements to form, scientists now report.
Explainer: What is a computer model?
“Black holes in these extreme environments are fussy eaters,” says Brian Metzger. He is an astrophysicist at Columbia University in New York City. These black holes can gulp down only so much matter at a time. What they don’t swallow blows off in a wind. This wind has lots of neutrons — subatomic particles having no electric charge. With a lot of them in the wind, it makes just the right conditions for the creation of heavy elements, Metzger says. At least that’s what simulations from his team’s new computer model suggest.
Metzger and his colleagues described those simulations and their results online May 8 in Nature.
Cooking up the elements
Their team has been trying to answer an age-old question: Where do the heaviest elements in the universe come from?
Astronomers know certain elements form inside stars and then spew into space when dying stars explode. These are elements such as carbon, oxygen and iron. Scientists call these light elements as they have less mass than those such as gold and platinum.
Scientists Say: Neutron star
Stars can’t make elements that are heavier than iron (like gold and platinum). To get such heavies there’s got to be a lot of neutrons. And they’ve got to be packed together tightly, creating an extreme environment. And in it, the centers of atoms — nuclei — absorb neutrons. After absorbing a lot of them, an atom’s nucleus will become unstable. To stabilize itself once more, it undergoes radioactive decay. In that decay, a neutron changes into a proton. And that makes a new element. Astrophysicists refer to this chain of reactions as the r-process.
Scientists had suspected that elements made this way could emerge when two stars collide. Specifically, it would happen when the smashup involves two dead stars known as neutron stars.
Explainer: What are gravitational waves?
Good evidence for the idea came out almost two years ago. That’s when astronomers spotted a collision between two neutron stars. It made waves that stretched and squeezed spacetime — the fabric of space. Astronomers call the ripples gravitational waves. Studying the smashup showed the neutron stars did spew out heavy elements, including gold, silver and platinum.
But the neutron-star idea explanation has shortcomings. Dense, dead stars can take a long time to collide. Heavy elements, however, have been found in ancient stars, ones that formed in the early universe. It’s not clear whether a neutron-star merger could happen that early in the history of the universe. But it would have to in order to explain the elements’ presence in those early stars.
There are spinning stars in space. Some of them collapse into black holes. Along the way, they may generate a lot of heavy elements — including gold.
Gold may be a glittery leftover from a newborn black hole’s messy first meal.
Gold is a heavy element. So is platinum. And uranium. These and many other heavy elements might form when rapidly spinning, massive stars collapse into newly formed black holes. Known as collapsars, these stars get their name from that collapse. And as this last dying stage of their lives take place, layers of gas around them explode. That collapse and explosion leave a disk of material swirling around each new black hole. When that black hole devours the surrounding material, the conditions become just right for gold, platinum and other heavy elements to form, scientists now report.
Explainer: What is a computer model?
“Black holes in these extreme environments are fussy eaters,” says Brian Metzger. He is an astrophysicist at Columbia University in New York City. These black holes can gulp down only so much matter at a time. What they don’t swallow blows off in a wind. This wind has lots of neutrons — subatomic particles having no electric charge. With a lot of them in the wind, it makes just the right conditions for the creation of heavy elements, Metzger says. At least that’s what simulations from his team’s new computer model suggest.
Metzger and his colleagues described those simulations and their results online May 8 in Nature.
Cooking up the elements
Their team has been trying to answer an age-old question: Where do the heaviest elements in the universe come from?
Astronomers know certain elements form inside stars and then spew into space when dying stars explode. These are elements such as carbon, oxygen and iron. Scientists call these light elements as they have less mass than those such as gold and platinum.
Scientists Say: Neutron star
Stars can’t make elements that are heavier than iron (like gold and platinum). To get such heavies there’s got to be a lot of neutrons. And they’ve got to be packed together tightly, creating an extreme environment. And in it, the centers of atoms — nuclei — absorb neutrons. After absorbing a lot of them, an atom’s nucleus will become unstable. To stabilize itself once more, it undergoes radioactive decay. In that decay, a neutron changes into a proton. And that makes a new element. Astrophysicists refer to this chain of reactions as the r-process.
Scientists had suspected that elements made this way could emerge when two stars collide. Specifically, it would happen when the smashup involves two dead stars known as neutron stars.
Explainer: What are gravitational waves?
Good evidence for the idea came out almost two years ago. That’s when astronomers spotted a collision between two neutron stars. It made waves that stretched and squeezed spacetime — the fabric of space. Astronomers call the ripples gravitational waves. Studying the smashup showed the neutron stars did spew out heavy elements, including gold, silver and platinum.
But the neutron-star idea explanation has shortcomings. Dense, dead stars can take a long time to collide. Heavy elements, however, have been found in ancient stars, ones that formed in the early universe. It’s not clear whether a neutron-star merger could happen that early in the history of the universe. But it would have to in order to explain the elements’ presence in those early stars.
Ask A Genius 1504: Testing Informational Cosmology: Super-Old Objects, Heavy Elements, and Future Telescopes
Scott Douglas Jacobsen presses for testability in informational cosmology. Rick Rosner argues near-term tests must target present-day signs of matter older than the universe’s apparent 13.8 billion-year age, despite observability limits: dim, delocalized halo objects and small lensing. He expects space based mega telescopes and AI analytics to reveal super old objects and excess heavy element…
Curiosity Daily Podcast: What to Do if You Can’t Sleep, Diet Soda Weight Loss Myths, and Gold from Neutron Stars
Learn about how scientists traced some of Earth’s heaviest elements to an ancient star collision; what to do if you’re lying in bed and you can’t sleep; and whether diet soda can help you lose weight.
In this podcast, Cody Gough and Ashley Hamer discuss the following stories from Curiosity.com to help you get smarter and learn something new in just a few minutes:
Some of Earth’s Gold Came From Two Neutron Stars That Collided Billions of Years Ago — https://curiosity.im/2HlKOdj
If You Can't Sleep, Get Out of Bed! — https://curiosity.im/2HotWCU
Will Diet Soda Help You Lose Weight? — https://curiosity.im/2YwbdLf
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An ancient neutron star collision occurred very, very close to our solar system — and we're all the better for it.
"Elements like plutonium, gold, platinum and others heavier than iron are created in a process called rapid neutron capture (also called the r-process), in which an atomic nucleus quickly gloms on to a bunch of free neutrons before the nucleus has time to radioactively decay. This process occurs only as a result of the universe's most extreme events — in stellar explosions called supernovas or colliding neutron stars — but scientists disagree about which of those two phenomena is chiefly responsible for the production of heavy elements in the universe."
عناصر سنگین در طی انفجار ستارهای یا روی سطوح ستاره های نوترونی از طریق جذب هسته های هیدروژن (پروتون ها) تولید می شوند. این اتفاق در دماهای بسیار بالا، اما در انرژی های نسبتا کم است می افتد. تیم تحقیقاتی بین المللی در دانشگاه گوته در حال حاضر موفق به بررسی پروتونها در حلقه ذخیره سازی GSI Helmholtzzentrum für Schwerionenforschung بوده است.
همانطور که دانشمندان در شماره جاری از آن گزارش می کنند نامه های بازنگری فیزیکی هدف آنها این بود که دقیقتر احتمال احتمال ضبط پروتون در سناریوهای آستروفیزیکی را تعیین کنیم. همانطور که دکتر ژان گلورویس از گروه تحقیقاتی فیزیک اتمی GSI توضیح می دهد، در این تلاش ها با دو چالش مواجه شده اند: “واکنش ها تحت شرایط استروفی فیزیکی در محدوده انرژی نامیده می شود که پنجره گامو است. در این محدوده، هسته ها تا حدودی آهسته است، و آنها را برای رسیدن به شدت مورد نیاز دشوار می سازد. علاوه بر این، مقطع عرضی – احتمال ضبط پروتون – به سرعت با انرژی کاهش می یابد. تا کنون تقریبا غیرممکن است که شرایط مناسب در یک آزمایشگاه ایجاد شود این نوع واکنش ها. “
رنه Reifarth، استاد فیزیک آزمایشی در دانشگاه گوته، پیش از ده سال پیش، یک راه حل را پیشنهاد کرد: انرژی کم در محدوده پنجره گاموی دقیق تر می تواند زمانی اتفاق می افتد که شریک واکنش سنگین در یک شتاب دهنده گردش می کند که در آن با یک پروتون ثابت گاز. او در سپتامبر 2015 با گروهی از محققان پیشین شغل Heimholtz موفق به کسب اولین موفقیت شد. از آن زمان، تیم او از طرف پروفسور یوری لیتویوف، استاد ارشد پروژه تحقیقاتی ES funded ASTRUm در GSI، حمایت زیادی کرده است.
در این آزمایش تیم بین المللی ابتدا یون های زئون را تولید کرد. آنها در حلقه ذخیره سازی تجربی ESR کاهش یافته و باعث ایجاد ارتباط با پروتون ها می شوند. این منجر به واکنش هایی شد که هسته های زنون یک پروتون را به دست آوردند و به سزیم سنگین تر تبدیل شدند – فرایندی مانند آن که در سناریوهای آستروفیزیکی رخ می دهد.
رنه Reifarth می گوید: “این آزمایش سهم تعیین کننده ای برای پیشرفت درک ما از هسته هسته ای در کیهان است.” “با تشکر از تسهیلات شتاب دهنده با کارایی بالا در GSI، ما توانستیم تکنیک تجربی را برای تضعیف شریک واکنش سنگین بهبود دهیم. اکنون ما دقیق تر از منطقه ای که نرخ های واکنش رخ می دهد، تاکنون تنها از لحاظ نظری پیش بینی شده است. این به ما اجازه می دهد دقیق تر تولید عناصر در جهان را مدل کنیم
