Galactic collision is not a general collision, but agravitationInteraction.Galaxy collisionuniverseIt is quite common in, and is also the key to the evolution of galaxies.
Galaxy collisionuniverseIt is quite common in, and is also the key to the evolution of galaxies.But galaxy collisions bring not only destruction, but also new life.
One possible result of galaxy collisions is galaxy mergers.When two galaxies collide and lack enough kinetic energy to continue traveling after collision, they will "fall" to each other, and finally merge into a galaxy after countless passes.On the other hand, if one galaxy participating in the collision is much larger than the other, then the former can basically remain the same after the collision, while the latter will be torn apart and become part of the former.Obviously, the influence of galaxy merging on the shape of the original two galaxies is greater than that of "big hitting small" or "small hitting big".
In most cases, galaxy collisions do not occur directly, and only lose some stars outside the galaxy. They are pulled away by strong gravity, and then thrown into space, leaving stars inside the galaxy immersed in the sea of stars between galaxies.If the collision happens directly, the result will be dramatic: twoSpiral galaxyUpon collision, the gas disk was driven into space by strong shock force, and then merged into a larger and brighter galaxy, forming an elliptical galaxy without gas matter.Bar spiral galaxies in the universeIrregular galaxyIt is the product of collision or interaction of several galaxies.Small galaxies gradually fall into the largest galaxy in a spiral shape until they are "swallowed" by large galaxies. These large galaxies become larger and larger, and continue to devour galaxies much smaller than them.
On《science》According to a report published in the magazine,There are massive black holes that can suddenly flip in x-shaped radio galaxy, which may be caused by absorbing black holes from other galaxies.
Most galaxies have supermassiveblack holeAnd its quality can reachSolar massMillions or billions of times.It is believed that the most active vortex will rotate at a terrible speed when it consumes gas and stars.The inhaled material rotates to form aSpaceA huge disk of moderate to intense jet energy.The survey shows that about 7% of the activeRadio galaxyJet flow with x-shape, or wing shape.Astronomers believe that these characteristics represent the centerblack holeThe motion of is very similar to the movement of the Earth's rotation axis with time.
Observational findings
Announce
edit
Eye like collision
In 1980,U.S.A、britain、NetherlandsCooperative launchInfrared astronomical satelliteIt is the first time to detect the intense infrared radiation of extremely bright infrared galaxies, which is more thanGalaxyIts infrared radiation is more than 100 times stronger.Astronomers estimate that the bright infrared light is caused by the absorption and re radiation of light clusters of newborn stars generated in the collision by dust matter when galaxies collide with each other.Hubble Space TelescopeIn the past three years, we have searched 123 extremely bright infrared galaxies within 3 billion light years, and found that 30% of them have obvious multiple mergers.In these magnificent multiple collisions, scientists have seen the final stage in the evolution sequence of the universe - small fragments combine to form largercelestial bodies。A large amount of matter comes out of the cracks in the galaxy, forming a long queue. The multiple nuclei formed by the contraction of matter are crowded together, and sometimes the "nest" of galaxies can be seen.This result shows the early appearance of the universe. At that time, galaxy collisions often occurred, and many new stars were born.
AM0644-741 Ring galaxy
On April 24, 1990, the Hubble Space Telescope sent back to Earth with the number AM0644-741Ring galaxyThe galaxy is located in the southern hemisphereconstellation Dorado Direction distanceGalaxyAbout 300 million light years away.The AM0644-741 galaxy, which looks like a diamond necklace, is composed of young and very hot star rings with a diameter of 150000 light-years.The ring galaxy was formed by the collision of two galaxies, one of which passed through the plane of the other.The huge gravitational impact changes the structure of the galaxy, forcing the air mass to compress and causing severeStar formation, a large number of young and hotcelestial bodiesComposed of a light blue necklace photographed by the Hubble Space Telescope.
September 2004, Europe XMM-Newton ObservatoryOf astronomers observed the largest ever recordedclusterCollision.In the case of two collidingclusterOne of them consists of nearly 1000SubgalaxiesThe other one also contains about 300 sub galaxies.TwoclusterAll inhydra, Distancesolar systemAbout 800 million light years.howeverclusterThe collision between the two is nothing like the car collision accidents that often occur on the highway: singleAstral bodyThe proportion in the total mass of galaxies is very small. In case of collision, they will penetrate and merge with each other, and converge into a new large star cluster.In the vast universe, it is not uncommon for galaxies to collide, but it is the first time that hundreds of galaxies infiltrate each other and the collision area extends more than 3 million light years at the same time.
Collision of two neutron stars
On May 9, 2005,NASAAn artificial satellite observed a violent energy explosion from a distant galaxy, which was the first time that two neutron stars collided violently.The information from this man-made satellite, called Swift, was quickly transmitted to astronomers on the ground, and then several hours of intense analysis and research were carried out.
neutron starCollisions are used to explain a series of puzzling giant ray bursts, which are called gamma ray bursts.Astronomers can be sure that "long bursts", that isGamma rayThe explosion is caused by the burnout of giant stars and the collapse of their dense coresAstral bodyBursting and formingblack holeProduced in the process of;The reason for the "short burst", that is, the gamma ray burst of less than 1 second, has always been a mystery.
In August 2007, American astronomers announced that they had recently used "Spitzer"Space telescopeSuccessfully observed four hugeGalaxy clusterThey collided with each other and merged into one of the largest galaxies ever observed by humans.
Four galaxy collision map
According to the observation results, these four giant galaxies have at leastGalaxySo large, each galaxy contains billions of stars.Astronomers predict that four galaxies will eventually merge into a single giant galaxy after collision, with a mass of aboutGalaxy10 times.
This galaxyColliding galaxyMission, No. CL0958+4702, is about 5 billion light years away.Using the infrared spectrograph installed on the Spitzer Space Telescope, astronomers observed thatElliptical galaxyThe ball emits a rare fan-shaped feather light.Three of the four galaxies haveGalaxyThe other is three times the size of the Milky Way.During the galaxy collision, billions of older stars were ejected, and half of the stars will eventually form a new oneGalaxy cluster。
"Antenna planet" collision
"Antenna planet" collision
In August 2010, according to the Daily Mail, NASA recently took an amazing picture with three high-tech telescopes. It can be seen from the picture that two huge objects have collidedGalaxy clusterIt is gradually blending with each other, and the picture is magnificent.
According to the analysis of scientists, this collision and fusion process has lasted for millions of years.The collision occurred about 62 million years ago and is still in progress.
The two galaxies are named "Antenna Galaxy" because their long tails look like antennas.The dense gas mass in the picture contains many elements, which will form a new generation in the futureplanet；The bright spot is partly fallen inblack holeOf unknown matter and falling starsneutron starCause.
New findings
Astronomershigh-power binocularsIt was found that there are two galaxies colliding with each other in the deep of the universe, and the collision image was captured through the rare and valuable "galactic lens"[1]。
Chief researcher Hugo Messias explained at the press conference: "Although astronomers usually use telescopes to observe galaxies, in some cases, the natural lens generated by the universe itself can greatly improve our ability to observe details."
Galaxy collision
The light behind a massive object can be bent by gravity, which is called "gravitational lensing effect".Astronomers use such a "cosmic magnifying glass" to study previously invisible objects.However, in order to make use of the gravitational lens effect, the object acting as the lens and the observed object must be very precisely in the same straight line, which is very rare.
The collision between the two galaxies occurred about half the age of the universe.Using gravitational lens effect,ALMA (Atacama large millimeter wave/submillimeter wave antenna array)VLA(radio telescopeGiant Array and many other telescopes have taken the best pictures.A nearly complete circle is formed around the foreground galaxy that acts as a lens, and behind it is an image of the fusion of two galaxies in the deep universe.This photo combines photos taken by the Hubble Space Telescope and the Keck II telescope in Hawaii.
The University of Chile de Concepci ó n and the University of Lisboa in Portugal, Messias, said: "The opportunity to form a line is indeed very rare, and it is often difficult to determine." By combining the images of telescopes with different wavelengths, we can find this contingency more effectively. "
Researchers said that the official designation of the galaxy being collided is HATLAS J142935.3-002836 (or H1429-0028 for short), which is the brightest object observed so far through the gravitational lens effect.Astronomers can integrate data from the Hubble Space TelescopeALMA、VLA、Keck Observatory combines observations from other telescopes to produce more detailed images.
Scientific prediction
Announce
edit
Astronomers, by observing the collision of galaxies, predicted theGalaxyPossible scenarios at the time of death.distanceGalaxy2.2 million light yearsandromedaGalaxy is the nearest galaxy to us.And it's the only thing that can be seen with the naked eyeSpiral galaxy。andromedaThe galaxy is approaching us step by step.Scientists predict that,GalaxyIt will be the same asandromedaGalaxies began to "get in touch" and merged in a billion years.But where we aresolar systemIt will not be disturbed, because even in the galaxy, the distance between stars is very far, and it will not collide as we imagine.
