Evidence of 'Pac-Man' black hole devouring neutron star detected by scientists for the first time a billion years ago

A black hole, known as the "Pac-Man" of the universe, is by far the most terrifying and dangerous being in the universe that we know of. It captures all matter in its vicinity with its powerful gravitational force, and not even "light" can escape. At the same time, its mystery has attracted the attention of countless astronomers, hoping to learn more about it.

On January 5, 2020, the U.S. Laser Interferometric Gravitational-Wave Observatory (LIGO) detected a "chirp" from deep in the universe about 900 million light-years away. This fleeting sound is unlike anything they have heard before. It is caused by gravitational waves, which are huge fluctuations in spacetime. How much power is needed to make gravitational waves propagate throughout the universe and to make the sound of a gravitational wave detector hitting Earth so far apart?

However, just as astronomers were still trying to find the answer, just 10 Earth days later, a similar sound came from the Virgo Gravitational-Wave Observatory in Italy - a twin born somewhere in the universe.

Astronomers were so excited that after careful analysis, they continued monitoring. Finally, the two signals were identified as coming from an extreme and unprecedented event in the universe - the collision of a black hole with a neutron star. Since the beginning of astronomical observations, scientists have only discovered collisions and mergers of black holes and neutron stars.

Black holes and neutron stars are the remnants of stars after they die. When a star's life is over, depending on its mass - if it is small enough to be "about 10 times more massive than our Sun" - it will collapse into a "zombie star" with a density of more than 100 million tons per cubic centimeter ", i.e. a neutron star; but if it is more massive, it will collapse into a black hole.

However, they are both the most famous "freaks" in the universe. They contain many mysteries that have not been thoroughly studied.

Scientists are still unable to find out what's inside a black hole, but it has one widely recognized and discussed feature - it swallows everything. Because of the strong gravitational force, everything that is sucked in, including light (which is how it got its name), never comes back, but where do they go? Similarly, something strange happens inside neutron stars, but I don't know what.

From the observations and calculations available to them, they can conclude that there would be some really strange physical phenomena inside black holes and neutron stars that are unknown to our current civilization - phenomena that have easily dismantled Earth civilization's understanding of the laws of physics and would not fit in the coffins of Newton and Einstein.

The findings were published in yesterday's Astrophysical Journal Letters. more than 1,000 scientists did their best to decipher the two rare collisions. The two events were named GW200105 and GW200115, the dates when Earth received the sound of their collision.

In the past two years, it has been suggested that some objects found in the universe are unusual. To say that they are neutron stars is too big, but to define them as black holes is too small - it is highly likely that they are the product of a merger between a black hole and a neutron star. The fact that they cannot be precisely defined and named for now means that GW200105 and GW200115 are likely to go down in history.

Professor Rory Smith, an astrophysicist at Monash University in Australia, said, "This is the first real and reliable detection of a neutron star merging with a black hole."

According to Smith, observing objects through gravitational waves is a form of "stellar paleontology" because it can reveal their evolutionary history and formation environment.

The "chirp" sound is central and contains a wealth of useful and interesting information - it can tell astrophysicists about the evidence of events in the universe that collide black holes and neutron stars, and analyze the masses and rotations of colliding objects. More importantly, "by studying this information, we can learn more about the survival of black holes and neutron stars in these binary systems and help us understand how they are locked in the dance of death."

For descriptive convenience, GW 200105 (chirp detected on Jan. 5, 2020) is named Lenny and GW 200115 (chirp detected on Jan. 15, 2020) is named Carl Carl. while they are similar events, the nature of the colliding objects is slightly different.

Researchers say that "Lenny" is the result of a collision between a black hole about nine times the mass of the Sun and a neutron star about 1.9 times the mass of the Sun, while "Carl" is the result of a merger between a black hole about six times the mass of the Sun and a neutron star about 1.5 times the mass of the Sun.

The collisions took place far from Earth in deep space, and the resulting sounds did not reach us until recently - yes, they were born about a billion years ago when we learned about them.

So when we "collide" or "merge," we're not entirely sure what happened then. But from what we know now, there are only two possibilities:

The first possibility is that perhaps for a long time, they were both trapped by each other's gravity and had difficulty separating, only hovering around each other. Eventually, the one with more mass and more gravity pulls the other into its arms - and with a "ki", the black hole swallows the neutron star with the "power of love".

The second possibility is that the black hole may "tear apart" the neutron star in a process called "tidal destruction. In this case, the black hole rips the material off the surface of the neutron star and steals it, creating a disk of debris around it - killing the neutron star with its "destructive power. Astronomers say, "That should produce an electromagnetic signal."

One of the Lennie or Carl, perhaps one of them, was created in the second case, which makes them even more valuable. They are the first pair of objects to be detected in a collisional merger of a black hole and a neutron star in the universe. After enough gravitational wave detections and analysis, they may be able to decode the behavior of the most extreme objects in the universe and reveal new laws of nature.