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Gravitational lenses

Gravitational lenses or gravitational mirage

 Automatic translation  Automatic translation Updated June 01, 2013

In astrophysics, an illusion that astronomers are familiar with is the gravitational lens or gravitational mirage.
A massive object, a cluster of galaxies, for example, which is between an observer and a distant light source, prints a strong curvature in space-time.
This has the effect of deflecting all light rays passing near the object, thereby distorting the images received by the observer.
This amplification of light, a distant celestial object by a massive star in front, was predicted by the theory of general relativity in 1917.
The massive objects modify the geometry of space and time in their neighborhood.
The light on the other hand always takes the shortest path, but in a curved space modified by the presence of a huge mass, the shortest path is not straight.
The light path is bent in the vicinity of massive stars. Most images of galaxies that are in this photograph are multiple images of a single ring galaxy.
A giant cluster of galaxies located in front acts as a huge gravitational lens.
In the foreground galaxies in this cluster are shown in yellow and behind the observed galaxy appears blue.
A gravitational lens can create multiple images of background galaxies.


The singular form of the galaxy blue background (small blue spot in the center of the image), allowed to infer that it is the same that we see in 4 hours, 10 hours, 11 hours and 12 hours.
The analysis showed that at least 33 images of 11 different background galaxies are discernible in this image.
This spectacular picture of the galaxy cluster CL0024 1654 was taken by the Hubble Space Telescope in November 2004.
Predicted by general relativity by Albert Einstein, a number of gravitational lensing have been observed by Hubble. Sometimes, when the alignment between two objects is perfect, the image of the distant object can take the form of a ring of light surrounding the subject at hand.
In case of perfect alignment between the observed source (a star for example), and another stellar object (a black hole for example), the black hole in front will act as a gravitational lens or deflector.
The observer will not see the star as such but rather as a ring, this ring is appointed, the Einstein ring.
A star, although a mass much lower than that of a galaxy, can also act as a gravitational lens.
The effect is obviously much less powerful, it is called, micro gravitational lens.

 gravitational lens, HST

Image: This gravitational lens shows a strange blue objects stretched.
They are spread in a circle in this picture, but are only multiple views of a single ring galaxy.
The singular form of the galaxy blue background (center of the cluster), allowed to infer that the same galaxy as we vote on this image to 4 hours, 10 hours, 11 hours and 12 hours.


Mirage on the five quasars


What's going on near the center of the galaxy clusters on the image to the cons?
At first glance, it seems that many are strangely elongated galaxies around the five brightest quasars, in white on the image.
In fact, a cluster of galaxies acts as a gigantic gravitational lens that distorts and multiplies the luminous objects located behind.
The five white points of light near the center of the cluster are in fact images of the same distant quasar. This image of the Hubble Space Telescope is so detailed that even the host galaxy surrounding the quasar is visible. The observation of the picture against shows that galaxies located in 2H and 4H are actually images of the same galaxy. A third image of this galaxy is about 10 am, the center of the cluster.


Image: The observation of the universe is sometimes misleading because by happy coincidence, we can see many strange and distant galaxies imaginary, they look like colorful jewels, like the picture against.
The group saw the huge galaxy gravitational lens is cataloged SDSS J1004 4112 and is about 7 billion light-years away towards the constellation Leo.

 around quasars gravitational mirage - HST

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