Astronomers have found some very bright spots of light in the night sky, but these spots are a bit weird. They look like small dots of light and stars, so they look mysterious at first. Is this a new star or something completely different? There is such a strange celestial body hidden in the Virgo galaxy cluster. From Earth, the celestial body 3C273 is like a nearby star, but scientists have made amazing discoveries when studying the light it emits. Its distance is very far away, not only outside Milky Way , but not even within any galaxy we can observe. It is far away over a billion light years! If it is so far away but so bright, then this must be the most bright object we know in the universe. And this is one of the reasons why they have been so mysterious for a long time. These celestial bodies are extremely bright, so even if they are far away, in our opinion, they are like neighboring stars. They are called celestial bodies of green stars, referred to as quasar for short. But what exactly are they? After a more detailed observation of quasars, we found that their positions are not randomly distributed, and they always appear in the center of a certain galaxy. Quasars are super bright cores in an extremely distant galaxy, and we can see them entirely because of their incredible energy. A quasar has a brightness that exceeds the entire galaxy, equivalent to hundreds of billions of stars, and all the energy released is concentrated in a single source of energy.
To date, the largest energy-level event that humans have witnessed on Earth is the largest atomic bomb that has been detonated in history. And we found that the energy released by quasars per second is greater than the atomic bomb explosion like 100 million memos. It is incredible that so much energy is concentrated into a very, very, very small space. If the quasar is so small, how can it release such powerful energy? How did such a bright, energetic but not too large object come into being? Where does such celestial energy come from?
There must be a powerful engine hidden in the quasar. What kind of celestial bodies can generate so much energy and create such a thing with such strong momentum? There is only one type of object in the universe, with a large enough mass and a high enough density, which is a black hole. This is the only thing known in the universe that has the potential to provide energy to quasars. Stars with a mass of 25 times larger than the Sun will suffer a catastrophic collapse after a lifetime of defeat in the battle against gravity. Their huge mass is compressed to one point, and the black hole is born. Black holes are very unique, and there are no other such celestial bodies in the universe. They are extremely mass and have extremely high density, compressing a lot of matter into a small space, and even causing huge distortions in the space. They can create an area called "Vision", the boundary of these monsters, that is, the Vision, a place without a turn around, and everything that crosses that line can never escape, even the light. Light can gallop freely in space and time, but the space and time in the black hole itself is bent, so light can never escape the black hole, and there are black holes everywhere in the universe. They vary in size, ranging from a conventional black hole with about three times the mass of to a supermassive black hole with an ultra-large specification supermassive black hole with . So we believe that quasars represent the largest black hole we see in the universe, that is, black holes with a mass of more than one billion times the sun, and the huge mass forms a huge gravity. We believe that only supermassive black holes can provide this energy, but quasars are brighter than the entire galaxy they are in, and black holes swallow everything. They are black, how could they become so bright! Black holes are greedy devourers, which attract dust and gas, which accumulate in a ring around the black hole, which we call accretion disk . You can imagine it as a huge vortex of matter, gradually falling into this supermassive black hole. All of these matter cannot fall down at once, so there will be a lot of friction in the accretion disk. The speed of dust and gas becomes faster and the friction becomes greater accordingly. It may cause huge friction at the speed of light.
If the speed of our hands reaches the speed of light, the huge friction will vaporize the hands and the temperature will become extremely high, so the temperature of the substance in the accretion disk can rise to millions of degrees Celsius. Radiation is generated when the substance warms up. Form the light we can see. The center of the galaxy emits light like this, and can be seen billions of light years away. The matter there becomes dense and hot, and quasars are present, so even if the black hole is the darkest celestial body in the universe, it can provide energy to the brightest celestial body in the universe. Quasars have confused astronomers for decades, and now it seems that even the brightest objects may not be visible.
In November 2015, astronomers used the Atacama large millimeter-wave array telescope to observe the interiors of the brightest galaxies in the universe. A simple and memorable quasar W2246 emits the light equivalent to 359 trillion suns. But our naked eyes cannot see it because it releases infrared rays . It is not an ordinary galaxy, but a hot dog galaxy. Hot Dogs are the abbreviation of hot dust covering galaxies. These galaxies are surrounded by the dust clouds of and between galaxies, blocking the powerful light emitted by this quasar. Because a quasar is a supermassive black hole, the surrounding matter will fall towards the black hole. It can be imagined that sometimes too much material around the black hole will completely block the quasar. The visible light of the quasar is absorbed by thick dust, but the infrared with low energy can escape, and in this band, its brightness is amazing. Not only is the Hot Dog Galaxy a cool name, it is also surprising. We found that half of the brightest quasars in the universe are hot dog galaxies. The quasars are very bright, and we can even observe some quasars located at the edge of the universe more than 13 billion light years away. This means that when they were born, it was less than 1 billion years after the Big Bang. Why do such monsters appear so soon after the universe was born? Scientists have discovered that there are many quasars with amazing brightness in the universe!
They are brighter than the galaxy they are in, and we can see them billions of light years away. Although the speed of light is as high as 300,000 kilometers per second, it takes a long time to cross the long distance between galaxies. Therefore, the quasars we see in the universe are actually millions or even billions of years ago, and the light they emit only came to our eyes tonight. Scientists at the Las Campenas Observatory in Chile in 2017 were targeted with a telescope at the oldest area in the universe and then got a big surprise. The quasar was born only about 600 million to 700 million years later than the Big Bang, and the mass of this black hole is about 800 million times the mass of the sun.
This is the oldest quasar discovered by mankind so far, and was born about 700 million years after the Big Bang. At that time, the universe was still a pot of thick soup composed mainly of hydrogen and helium . The energy of the quasar comes from a supermassive black hole, but in the process of the evolution of the universe, it is still very mysterious to discover a black hole that was born so early but so big. One of the most important questions in astronomy is how these supermassive black holes were formed, and why did they appear in the universe so early? This is an interesting mystery. The location of the quasars we discovered is almost far to the limit and that these celestial bodies existed in the earliest galaxies, which means that at that time, they could gather to form millions or even billions of times the mass of the sun. But we are not sure how this actually happens.
This mystery is still hidden in the growth rate of black holes. They swallow matter at an astonishing speed and continue to grow. We always eat full when we eat, but black holes always remain hungry and they are insatiable. Black holes can swallow everything, and matter that is too close to them grows bigger and bigger, but their growth rate is still limited. Billion years after the birth of the universe, such a short time is not enough to allow them to grow to 1 billion times as large as the sun's mass, so in addition to this method of devouring, there must be other ways to cause the seeds of these black holes to form.
We now believe that this supermassive black hole with a mass of 1 billion times the sun was grown from smaller seed black holes. Black holes are usually formed by the explosion of stars with a mass of more than 25 times the sun, and these black holes are small. To form a supermassive black hole, giant stars born from supermassive stars in the early stages of the universe are needed. That is a huge gas cloud , which is mainly composed of hydrogen and a little helium. Only these substances can collapse as they cool down, forming such huge stars, or huge hydrogen balloons in space.
Supermassive stars have a short lifespan and fleeting moments. This seed black hole will form when they die, which may be one of the ways in which such huge seeds are produced. But there is still a problem. These supermassive stars seem to be unable to form seed black holes large enough, and there should be other ways to form a black hole of 1 billion times the mass of the sun in less than 1 billion years.
Scientists are working to study the more different quasars we discover, the more we can know what these seeds that form quasars are, or let us know new ways to quickly create these huge black holes. The more we study quasars, the more we understand the early universe. But they also reveal some unique properties.
Recently we found some galaxies that were torn out of the holes, and the culprit was some death rays released at a speed close to the light. The universe is full of galaxies, and they appear peaceful and quiet from a distance, but by looking closer, you can find evidence of extreme violence and destruction. Some galaxies have scars extending from the center of galaxies for hundreds of thousands of light years. What caused such great damage? Observe at different wavelengths and you can find the real murderer. Two huge energy beams emitted by the quasar in the center of the galaxy ejected from the center of the quasar, tearing the galaxy into space, and forming a hole in the surrounding gas clouds. The energy intensity of these jets is amazing, breathtaking and jaw-dropping.
Imagine the energy contained in these types of body jets, which can sometimes accelerate matter of many times the mass of the sun to near the speed of light and then spray it hundreds of thousands of light years away. These jets are like the super- high-energy particles ejected from the center of the quasar into dense energy beams. Moving at a speed of several million kilometers per hour, the temperature is as high as trillions of degrees. Ordinary quasars are already very powerful, but quasars that emit jets are even more powerful! This energy is equivalent to gathering the energy of billions or even trillions of stars into a narrow jet, which is sprayed into the universe like a death ray. If you are too close, on this jet jet route, you shouldn't be able to resist it for long, and it's not just the galaxy that is suffering from the destruction. The jet ejected is even more powerful than the Death Star. It can not only destroy planets blocking the way, but also stars and the entire star system cannot be spared. The 3C321 galaxy encountered this kind of bad luck.
In visible light, we can only see a pair of galaxies. But at different wavelengths, we can see a larger galaxy that emits powerful death rays, tearing apart the adjacent smaller galaxies and shooting into the universe. Imagine being hit directly by a jet on the jet route, and that's all, and the entire planet will face disaster. Planets are destroyed, stars explode, and these jets can be sprayed into very faraway places in space. The largest jet length we have discovered is 1.4 million seconds gap, and a million seconds gap is about 3 million light years, so its length from start to finish is about 5 million light years. The jet will stop after it rushes into the intergalactic medium, that is, the thin gas layer around the galaxy. It can hit intergalactic medium hundreds of thousands of light years away, causing it to burn. The impact releases a huge shock wave.
However, quasars that can emit jets seem to be rare, only 10% of quasars have jets, and no one knows the reason. We can clearly observe quasars emit huge jets in the universe, and the wonders are, we don’t know how they form.This process is very complicated, and it is difficult for us to figure out what exactly the astrophysics phenomenon is happening there. So we believe that the jet is formed in the accretion disk, that is, the gas vortex disk hovering near the black hole's horizon, which is the most reasonable theory.
We believe that there are fast moving charged particles near supermassive black holes, which creates a magnetic field, which rotates around the black hole and forms a powerful magnetic field. magnetic field strength continues to grow, wrapping up the black hole, and all charged particles in the accretion disk will move in the direction of the magnetic field. Celestial bodies with magnetic fields must have magnetic pole . In this place, matter can escape, and the particles circulate and rise into a jet. The pressure in the accretion disk is very high, and this magnetic field is also very strong. They rotate closely around the rotating black hole, and finally obtain an extremely powerful concentrated jet. The jet ejected from the poles of the black hole can reach 99% of the speed of light. These quasars are huge generators that can convert gravitational energy into magnetic energy, which is then converted into kinetic energy when the jet is emitted. They carry huge energy that can be observed on the other side of the universe. Quasars continue to haunt astronomers. Now they have brought another problem that quasars should take millions of years to launch, but recently we have detected quasars that can brighten in an instant.
