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The concept of this artist shows the most distant quasar and the furthest supermassive black hole that feeds it. ULAS J1342 + 0928 corresponds to a distance of 29 billion light-years with a red shift of 7.54; it is the most distant quasar / supermassive black hole ever discovered. Its light reaches our eyes today, in the radio part of the spectrum, as it was released barely 690 million years after the Big Bang.Robin Dienel / Carnegie Institution for Science
One of the biggest challenges of modern astrophysics is to describe how the Universe went from a uniform place without planets, stars or galaxies to the rich, structured and diverse cosmos we see. aujourd & # 39; hui. As far as we can see, at the time when the Universe only had a few hundred million years, we find a multitude of fascinating objects. Stars and star clusters exist in abundance; galaxies with maybe a billion stars illuminate the Universe; even quasars with very large black holes formed before the Universe was even a billion years old.
But how did the Universe create black holes so gigantic in such a short time? After decades of conflicting stories, scientists are finally thinking that we know what has happened.
An artist's design of what the Universe might look like when it will form stars for the first time. Stars can reach hundreds or even a thousand solar masses and lead to the relatively fast formation of a black hole in the mass that the first quasars are known to possess.NASA / JPL-Caltech / R. Injured (SSC)
Only 50 to 100 million years after the Big Bang, the very first stars began to form. Massive gas clouds have begun to collapse, but, consisting solely of hydrogen and helium, they have trouble dissipating heat and dissipating their energy. As a result, these masses that form and grow by gravity must become much more massive than those that form the stars today, which has repercussions on the type of stars.
While today, we usually form stars that represent about 40% of the mass of the Sun, the very first stars were about 25 times more massive, on average. Because you need to cool down to collapse, only the largest and most massive tufts that form early can lead to stars. The average "first star" could be ten times more massive than our Sun, with many individual stars reaching hundreds or even thousands of solar masses.
The spectral classification system (modern) Morgan – Keenan, with the temperature range of each class of stars indicated above, in Kelvin. The vast majority of today 's stars are M – class stars, with only one star known from classes O or B to less than 25 parsecs. Our sun is a class G star. However, at the beginning of the Universe, almost all stars were class O or B stars, with an average mass 25 times higher than the current average.LucasVB, Wikimedia Commons user, E. Siegel additions
Most of these stars will end up in a supernova, leading to either a neutron star or a small black hole of low mass. But without any heavy elements, the most massive stars will reach temperatures so high in their nuclei that photons, individual light particles, can become so energetic that they will spontaneously start producing pairs of matter and particles. 39, antimatter from pure energy.
You may have heard of Einstein E = mc2, and this is perhaps its most powerful application: a form of pure energy, like photons, can create huge particles as long as the fundamental quantum rules governing nature are respected. The easiest way to create matter and antimatter is to make the photons produce an electron / positron pair, which will happen on its own if the temperatures are high enough.
This diagram illustrates the process of producing pairs that, according to astronomers, triggered the hypernova event called SN 2006gy. When sufficiently high energy photons are produced, they create electron / positron pairs, causing a pressure drop and an embracing reaction destroying the star. The maximum brightnesses of a hypernova are many times greater than any other "normal" supernova.NASA / CXC / M. Weiss
In these ultra-massive stars, as in all stars, the gravitation tries to pull all this material towards the center. But photons, as well as all the radiation produced in the nuclei of these stars, repel and hold the star in the air, preventing its collapse.
However, when you start producing electron-positron pairs from these photons, you lose some of that radiation pressure. You depletes your star's ability to withstand gravitational collapse. And while it is true that there are some narrow mass ranges that lead to the total destruction of the star, a large part of the number of cases leads directly to the collapse of the star to form a black hole.
Supernova types as a function of initial mass and initial content in elements heavier than helium (metallicity). Note that the first stars occupy the lower row of the graph, being free of metal, and the black areas correspond to black holes collapsed directly.Fulvio314 / Wikimedia Commons
This is a remarkable step! This means that the most massive stars, with hundreds or even a thousand solar masses, can be formed when the Universe is only 100 million years old: less than 1% of its current age. These stars will use nuclear fuel the fastest, in one or two million years. And then, their nuclei will become so hot that they will begin to turn the photons into particles and antiparticles, which will cause the star to collapse and heat up even faster.
Once you have exceeded a certain threshold, all you can do is collapse. And it's not just theory either; we saw stars collapse directly without supernova, leading directly to what could only be a black hole.
The photos visible / close to the infrared spectrum of Hubble show a massive star, about 25 times higher than the mass of the Sun, which disappeared, without supernova nor other explanation. The direct collapse is the only reasonable explanation of the candidate.NASA / ESA / C. Kochanek (OSU)
But that's just the beginning. Whenever you have a large group of massive objects acting primarily under the effect of gravity, different objects are struck by these interactions. The least massive objects are those that are easiest to eject, while the most massive objects are the most difficult to eject. When these stars, gas clouds, clusters and black holes dance, they undergo what is called mass segregation: the heavier objects fall to the center of the gravitation, where they interact and can even merge.
Suddenly, instead of a few hundred black holes of a few hundred or a few thousand solar masses, you can end up with a single black hole of about 100,000 solar masses or more.
Cataclysmic events occur throughout the galaxy and in the Universe, from supernovae to active black holes to neutron stars and much more. In a cluster or block that forms many black holes, they will gravitationalally attract and eject other smaller objects, which will result in a series of huge mergers and the growth of a large central black hole.J. Wise / Georgia Institute of Technology and J. Regan / Dublin City University
Although, gravitationally, it can take tens of millions of years, it is only a cluster of stars! The Universe, since its inception, has formed these star clusters all over the place, and these clusters then begin to attract by gravity. Over time, these disparate star clusters will influence each other and gravity will bring them together.
At the time, the Universe did not exceed 250 million years, they will have already begun to merge. en masse, leading to the first proto-galaxies. Gravity is a force that really promotes overdog and, over time, tens, hundreds and even thousands of these initial clusters can come together to form larger and larger galaxies. The cosmic Web fuses structures into ever larger structures.
Large-scale projection through the Illustris volume at z = 0, centered on the largest cluster, 15 Mpc / h depth. Indicates dark matter density (left) in transition to gas density (right). The large-scale structure of the universe can not be explained without dark matter. The complete suite of what is present in the Universe dictates that the structure first forms on a small scale, eventually becoming larger and larger.Illustris Collaboration / Illustris Simulation
This can easily lead us to masses of tens of millions of solar masses when we reach the first galaxies, but something else also happens. It's not just the black holes that merge to build supermassives in the center; it's any matter that falls on them! These first galaxies are compact objects and are full of stars, gas, dust, star clusters, planets, and so on. Whenever something approaches too much of a black hole, it risks being eaten up.
Remember that gravity is an uncontrollable force: the more mass you have, the more mass you attract. And if something approaches too much of a black hole, its material is stretched and heated, where it will be part of the accretion disk of the black hole. Part of this material will be heated and accelerated, where it can emit jets of quasar. But part of it will also fall, resulting in even greater growth of the mass of the black hole.
When black holes feed on material, they create an accretion disk and a bipolar jet perpendicular to it. When a jet coming from a supermassive black hole points us at the finger, we call it a BL Lacertae object or blazar. It is now thought to be a major source of cosmic rays and high-energy neutrinos.NASA / JPL
If there was a word of vocabulary that astrophysicists who are studying the growth of an object by gravity want the general public to be aware, it would be this strange: nonlinear. When you have a region of space denser than the average, it attracts the material. If the density is a few percent below average, the gravitational pull is only a few percent more efficient than average. You double the amount of your excessive expenses and you double the amount of your ability to attract things more efficiently.
But when you reach a certain threshold, about twice the average, you become much more than twice as effective at attracting other subjects. When you start to "win" the gravitation war, you gain more and more over time. As a result, not only are the most massive regions growing fastest, but they are eating them all around. At the end of half a billion years, you can be huge.
The distant galaxy MACS1149-JD1 is gravitated by a foreground group, which allows it to be imaged at high resolution and in multiple instruments, even without next-generation technology.ALMA (ESO / NAOJ / NRAO), TELESCOPE HUBBLE SPACE NASA / ESA, W. ZHENG (JHU), MR POSTMAN (STSCI), THE CLASH TEAM, HASHIMOTO AND AL.
The first galaxies and quasars we have ever found are some of the brightest and most massive we expected to exist. They are the big winners of the gravitational wars of the first universe: the ultimate cosmic overdogs. By the time our telescopes reveal them, 400 to 700 million years after the Big Bang (the first quasar dates back 690 million years), they already have billions of stars and black holes supermassifs of several hundreds of millions of solar masses.
But it is not a cosmic catastrophe; This is a proof that highlights the endless gravitational power in our universe. Seeded from the first generation of stars and relatively large black holes that they produce, these objects fuse and grow within a cluster, then further expand when the clusters merge to to form galaxies and galaxies to fuse to form larger galaxies. Today, we have black holes of tens of billions as massive as the Sun. But even in the very early stages, black holes of a billion solar mass are within our reach. By removing the cosmic veil, we hope to learn exactly how they grow up.
To learn more about the nature of the universe when:
- How was it when the Universe inflated?
- How was it when the Big Bang started?
- How was it when the Universe was at the hottest?
- How was it when the Universe created more matter than antimatter?
- How was it when the Higgs gave mass to the universe?
- How was this the first time we made protons and neutrons?
- How was it when we lost the last of our antimatter?
- How was it when the Universe created its first elements?
- How was it when the Universe created the atoms?
- How was it when there were no stars in the universe?
- How was it when the first stars started to illuminate the universe?
- How was it when the first stars died?
- How was it when the Universe created its second generation of stars?
- How was it when the Universe created the very first galaxies?
- How was it when the light of the stars went through the neutral atoms of the universe?
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The concept of this artist shows the most distant quasar and the furthest supermassive black hole that feeds it. ULAS J1342 + 0928 corresponds to a distance of 29 billion light-years with a red shift of 7.54; it is the most distant quasar / supermassive black hole ever discovered. Its light reaches our eyes today, in the radio part of the spectrum, as it was released barely 690 million years after the Big Bang.Robin Dienel / Carnegie Institution for Science
One of the biggest challenges of modern astrophysics is to describe how the Universe went from a uniform place without planets, stars or galaxies to the rich, structured and diverse cosmos we see. aujourd & # 39; hui. As far as we can see, at the time when the Universe only had a few hundred million years, we find a multitude of fascinating objects. Stars and star clusters exist in abundance; galaxies with maybe a billion stars illuminate the Universe; even quasars with very large black holes formed before the Universe was even a billion years old.
But how did the Universe create black holes so gigantic in such a short time? After decades of conflicting stories, scientists are finally thinking that we know what has happened.
An artist's design of what the Universe might look like when it will form stars for the first time. Stars can reach hundreds or even a thousand solar masses and lead to the relatively fast formation of a black hole in the mass that the first quasars are known to possess.NASA / JPL-Caltech / R. Injured (SSC)
Only 50 to 100 million years after the Big Bang, the very first stars began to form. Massive gas clouds have begun to collapse, but, consisting solely of hydrogen and helium, they have trouble dissipating heat and dissipating their energy. As a result, these masses that form and grow by gravity must become much more massive than those that form the stars today, which has repercussions on the type of stars.
While today, we usually form stars that represent about 40% of the mass of the Sun, the very first stars were about 25 times more massive, on average. Because you need to cool down to collapse, only the largest and most massive tufts that form early can lead to stars. The average "first star" could be ten times more massive than our Sun, with many individual stars reaching hundreds or even thousands of solar masses.
The spectral classification system (modern) Morgan – Keenan, with the temperature range of each class of stars indicated above, in Kelvin. The vast majority of today 's stars are M – class stars, with only one star known from classes O or B to less than 25 parsecs. Our sun is a class G star. However, at the beginning of the Universe, almost all stars were class O or B stars, with an average mass 25 times higher than the current average.LucasVB, Wikimedia Commons user, E. Siegel additions
Most of these stars will end up in a supernova, leading to either a neutron star or a small black hole of low mass. But without any heavy elements, the most massive stars will reach temperatures so high in their nuclei that photons, individual light particles, can become so energetic that they will spontaneously start producing pairs of matter and particles. 39, antimatter from pure energy.
You may have heard of Einstein E = mc2, and this is perhaps its most powerful application: a form of pure energy, like photons, can create huge particles as long as the fundamental quantum rules governing nature are respected. The easiest way to create matter and antimatter is to make the photons produce an electron / positron pair, which will happen on its own if the temperatures are high enough.
This diagram illustrates the process of producing pairs that, according to astronomers, triggered the hypernova event called SN 2006gy. When sufficiently high energy photons are produced, they create electron / positron pairs, causing a pressure drop and an embracing reaction destroying the star. The maximum brightnesses of a hypernova are many times greater than any other "normal" supernova.NASA / CXC / M. Weiss
In these ultra-massive stars, as in all stars, the gravitation tries to pull all this material towards the center. But photons, as well as all the radiation produced in the nuclei of these stars, repel and hold the star in the air, preventing its collapse.
However, when you start producing electron-positron pairs from these photons, you lose some of that radiation pressure. You depletes your star's ability to withstand gravitational collapse. And while it is true that there are some narrow mass ranges that lead to the total destruction of the star, a large part of the number of cases leads directly to the collapse of the star to form a black hole.
Supernova types as a function of initial mass and initial content in elements heavier than helium (metallicity). Note that the first stars occupy the lower row of the graph, being free of metal, and the black areas correspond to black holes collapsed directly.Fulvio314 / Wikimedia Commons
This is a remarkable step! This means that the most massive stars, with hundreds or even a thousand solar masses, can be formed when the Universe is only 100 million years old: less than 1% of its current age. These stars will use nuclear fuel the fastest, in one or two million years. And then, their nuclei will become so hot that they will begin to turn the photons into particles and antiparticles, which will cause the star to collapse and heat up even faster.
Once you have exceeded a certain threshold, all you can do is collapse. And it's not just theory either; we saw stars collapse directly without supernova, leading directly to what could only be a black hole.
The photos visible / close to the infrared spectrum of Hubble show a massive star, about 25 times higher than the mass of the Sun, which disappeared, without supernova nor other explanation. The direct collapse is the only reasonable explanation of the candidate.NASA / ESA / C. Kochanek (OSU)
But that's just the beginning. Whenever you have a large group of massive objects acting primarily under the effect of gravity, different objects are struck by these interactions. The least massive objects are those that are easiest to eject, while the most massive objects are the most difficult to eject. When these stars, gas clouds, clusters and black holes dance, they undergo what is called mass segregation: the heavier objects fall to the center of gravitation, where they interact and can even merge.
Suddenly, instead of a few hundred black holes of a few hundred or a few thousand solar masses, you can end up with a single black hole of about 100,000 solar masses or more.
Cataclysmic events occur throughout the galaxy and in the Universe, from supernovae to active black holes to neutron stars and much more. In a cluster or block that forms many black holes, they will gravitationalally attract and eject other smaller objects, which will result in a series of huge mergers and the growth of a large central black hole.J. Wise / Georgia Institute of Technology and J. Regan / Dublin City University
Although, gravitationally, it can take tens of millions of years, it is only a cluster of stars! The Universe, since its inception, has formed these star clusters all over the place, and these clusters then begin to attract by gravity. Over time, these disparate star clusters will influence each other and gravity will bring them together.
At the time, the Universe did not exceed 250 million years, they will have already begun to merge. en masse, leading to the first proto-galaxies. Gravity is a force that really promotes overdog and, over time, tens, hundreds and even thousands of these initial clusters can come together to form larger and larger galaxies. The cosmic Web fuses structures into ever larger structures.
Large-scale projection through the Illustris volume at z = 0, centered on the largest cluster, 15 Mpc / h depth. Indicates dark matter density (left) in transition to gas density (right). The large-scale structure of the universe can not be explained without dark matter. The complete suite of what is present in the Universe dictates that the structure first forms on a small scale, eventually becoming larger and larger.Illustris Collaboration / Illustris Simulation
This can easily lead us to masses of tens of millions of solar masses when we reach the first galaxies, but something else also happens. It's not just the black holes that merge to build supermassives in the center; it's any matter that falls on them! These first galaxies are compact objects and are full of stars, gas, dust, star clusters, planets, and so on. Whenever something approaches too much of a black hole, it risks being eaten up.
Remember that gravity is an uncontrollable force: the more mass you have, the more mass you attract. And if something approaches too much of a black hole, its material is stretched and heated, where it will be part of the accretion disk of the black hole. Part of this material will be heated and accelerated, where it can emit jets of quasar. But part of it will also fall, resulting in even greater growth of the mass of the black hole.
When black holes feed on material, they create an accretion disk and a bipolar jet perpendicular to it. When a jet coming from a supermassive black hole points us at the finger, we call it a BL Lacertae object or blazar. It is now thought to be a major source of cosmic rays and high-energy neutrinos.NASA / JPL
If there was a word of vocabulary that astrophysicists who are studying the growth of an object by gravity want the general public to be aware, it would be this strange: nonlinear. When you have a region of space denser than the average, it attracts the material. If the density is a few percent below average, the gravitational pull is only a few percent more efficient than average. You double the amount of your excessive expenses and you double the amount of your ability to attract things more efficiently.
But when you reach a certain threshold, about twice the average, you become much more than twice as effective at attracting other subjects. When you start to "win" the gravitation war, you gain more and more over time. As a result, not only are the most massive regions growing fastest, but they are eating them all around. At the end of half a billion years, you can be huge.
The distant galaxy MACS1149-JD1 is gravitated by a foreground group, which allows it to be imaged at high resolution and in multiple instruments, even without next-generation technology.ALMA (ESO / NAOJ / NRAO), TELESCOPE HUBBLE SPACE NASA / ESA, W. ZHENG (JHU), MR POSTMAN (STSCI), THE CLASH TEAM, HASHIMOTO AND AL.
The first galaxies and quasars we have ever found are some of the brightest and most massive we expected to exist. They are the big winners of the gravitational wars of the first universe: the ultimate cosmic overdogs. By the time our telescopes reveal them, 400 to 700 million years after the Big Bang (the first quasar dates back 690 million years), they already have billions of stars and black holes supermassifs of several hundreds of millions of solar masses.
But it is not a cosmic catastrophe; This is a proof that highlights the endless gravitational power in our universe. Seeded from the first generation of stars and relatively large black holes that they produce, these objects fuse and grow within a cluster, then further expand when the clusters merge to to form galaxies and galaxies to fuse to form larger galaxies. Today, we have black holes of tens of billions as massive as the Sun. But even in the very early stages, black holes of a billion solar mass are within our reach. By removing the cosmic veil, we hope to learn exactly how they grow up.
To learn more about the nature of the universe when:
