Gold mine. Opened gravitational waves stars

Золотая жила. Открыты гравитационные волны звезд

Recorded gravitational waves the merger of neutron stars

Details about the most important discovery this year – gravitational waves from merging neutron stars.

Astronomers first recorded gravitational waves from merging neutron stars. The event took place at the Observatory LIGO 17 August, but was told about it only on October 16.

Observations were engaged in 70 groups of scientists, co-authored one of the articles dedicated to this event, steel 4.6 thousands of scientists – more than a third of all the astronomers of the world.

Корреспондент.net versed in discovery, which could pave the course for a new era in astronomy and explain the cosmic origins of gold.

 

Centennial dream of scientists

Gravitational waves predicted by albert Einstein in the General theory of relativity 100 years ago. Since then, scientists tried to prove their existence.

Gravitational waves are disturbances of space-time emitted by moving masses and propagating with the speed of light.

Золотая жила. Открыты гравитационные волны звезд

Observatory LIGO / ligo.caltech.edu

The first time they managed to capture 14 September 2015, with huge detectors, interferometric Observatory of gravitational waves (LIGO).

About the discovery was announced on 11 February 2016 and October 2017 American researchers Pile Thorne, Rainer Weiss and Barry Berisha awarded the Nobel prize in physics for work on the creation of LIGO.

About a billion years ago at a distance of 1.3 billion light years from earth, the two black holes with a mass of 36 and 29 solar masses circling around one another, gradually approaching under the influence of mutual gravitation, not yet collided and merged together.

As a result of such clashes there has been a tremendous release of energy – a fraction of a second to approximately three solar masses has turned into gravitational waves, the maximal radiation power of which was about 50 times more than the entire visible Universe.

Convergence, collision and merger of two black holes has led to the confusion of the surrounding space-time continuum and sent in all directions at the speed of light powerful gravitational waves.

By the time when these waves reached our planet, the once powerful roar of cosmic proportions has turned into a barely discernible whisper. It and fixed on LIGO.

Whispers of gravitational waves you can listen to:

Prior to the registration of gravitational waves on the behavior of gravity, scientists knew only by the example of celestial mechanics, interaction of celestial bodies. But it was clear that a gravitational field has waves and space-time can be deformed in a similar way.

What we haven’t seen gravitational waves, there was a white spot in modern physics. Now this gap is closed, put another brick in the Foundation of modern physical theory. This fundamental discovery. Nothing comparable over the last year.

After further technology development we can talk about gravitational astronomy – about how to observe the traces of the most high-energy events in the Universe.

 

A new discovery

The beginning of a new era in astronomy and physics was sounded on Monday the statement by scientists that they found ripples in space-time known as gravitational waves, which were formed as a result of collision of two neutron stars.

On 17 August these waves from outer space reached Earth in the Indian ocean and was registered two detector stations LIGO and European Virgo detector, located in Italy.

This is the fifth case in the last two years, when scientists record these waves. However, all the observed gravitational waves has arisen from the merger of black holes.

These black holes have such an enormous density that do not produce light. Therefore, the merger of black holes in fact cannot be detected by conventional telescopes.

However, the merger of neutron stars begins with the objects that are compared to black holes can be very easy. A neutron star is highly compressed – completed his age of a massive star, and it formed after a supernova explosion.

Its gravitational field is strong enough to compress and destroy matter mass of the whole Sun into a sphere of neutrons the size of a large city.

Thus, it is not a star in the usual sense, and to a greater extent the nucleus of an atom the size of a small city.

The force of attraction of the neutron star is too small to hold the light, so the flash from the collision of two such stars can penetrate the space, creating not only gravitational waves, but also one of the brightest fireworks in the Universe.

Fireworks could observe all astronomers and physicists who knew about the event, well, the lucky ones, who brought the galaxy NGC 4993 in the constellation Hydra.

When the initial pulse of gravitational waves a signal of the beginning of the merger, the fireworks consisted of gamma-ray bursts with a length of two seconds and an afterglow of different wavelengths, which lasted several weeks.

Nine days after, fixate pulse astronomers were able to image the x-ray range, and after 16 days in RF. After a while the Sun came closer to the galaxy and September observations become impossible.

Recording flash the merger of neutron stars:

As the scientists told, the mass of the merged neutron stars was 1.1 and 1.6 solar masses (more accurately determined the total mass – about 2.7 solar masses). The first gravitational waves has arisen, when the distance between the objects was 300 kilometers.

The big surprise was the short distance from this system to the Earth – about 130 million light years.

For comparison, this is only 50 times farther than from Earth to the Andromeda galaxy, and almost an order of magnitude smaller than the distance from our planet to black holes, the collision which was fixed earlier LIGO and Virgo.

In addition, the collision was closest to the Earth source of short gamma-ray burst.

Gravitational waves from merging neutron stars can be streamed:

Here:

Double neutron star known since 1974. However, until now all known such systems are in our Galaxy, and the stability of their orbits was sufficient, so they do not run in the next million years.

New pair of stars so close that we began the collaboration and began to develop the process of transfer of matter.

The event was called Bulanovoj. Literally, it means that the brightness of the flash was about a thousand times more powerful than the typical flash of new stars – binary systems in which the compact companion pulls on the matter.

Why is this discovery so important

Gamma-ray bursts are among the most energetic phenomena in the Universe. One such power surge sufficient to second to throw out into the surrounding space as much energy as the Sun generates over 10 million years.

Distinguish between short and long gamma-ray bursts; it is believed to be different in mechanism of the phenomenon. For example, the source of the long bursts are considered to be the collapse of massive stars.

Sources of short gamma-ray bursts are believed to be mergers of neutron stars. However, until now direct evidence for this was not. The new observations is the most compelling to date, the proof of the existence of this mechanism.

Discovery also explained where in the Universe the heavy metals. Nucleosynthesis is the fusion of nuclei in stars – lets get a huge range of chemical elements.

For light nuclei fusion reaction proceeds with release of energy, and overall energetically favorable. For elements whose mass is close to the mass of iron, the energy gain is not so large.

Because of this, the stars almost do not form elements heavier than iron – the exceptions are supernova explosions.

However they are insufficient to explain the prevalence of gold, the lanthanides, uranium and other heavy elements in the Universe.

In 1989, physicists have suggested that it can respond to r-nucleosynthesis in mergers of neutron stars.

Spectral investigations of these events showed clearly marks the birth of heavy elements. Astronomers have detected the presence of cesium, tellurium, gold and platinum. There is also evidence of the formation of xenon, iodine and antimony.

According to the estimates of physicists, the result of the study clashes were discarded total weight of light and heavy elements, equivalent to 40 Jupiter masses. Only one gold, according to theoretical models, and produces about ten mass of the moon.

This is conclusive evidence that the merger of neutron stars is a cosmic melting pot, in which there are heavy elements of our Universe, including uranium, platinum and gold.

Thus, the radioactive material in a nuclear reactor or gold in a wedding ring are the result of the collision the smallest, most dense and most exotic stars in our Universe – neutron.

This discovery will help to resolve ongoing debates on the question of cosmic origin of heavy elements, which theorists are more than half a century.

The main part of the hydrogen and helium in our Universe appeared in the first moments after the big Bang. And most of the light elements such as oxygen, carbon, nitrogen, and so forth, were formed by nuclear fusion in stars.

But the question about the origin of the heaviest elements so far not been answered.

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