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Quasar

Quasi Stellar Radio source

 Automatic translationAutomatic translation Category: stars
Updated June 01, 2013

Quasars (Quasi-Stellar Radio Sources) are the cores of galaxies in the process of weakening or expansion that are at very large distances, billions of light years. Quasars are the brightest objects in the known Universe but only appear as strange stars low. The images of these areas of low brightness seen by the telescope CFHT (Canada-France-Hawaii Telescope) show, when subtracting the signal corresponding to the quasar, a resulting image that looks like an elliptical galaxy. Quasars can be observed in the spectrum of electromagnetic radio waves, infrared, the visible light, ultraviolet, X-rays and gamma rays. Quasars radiate strongly and have a brightness seemed to come from hundreds of galaxies, but a quasar is about a million times smaller than ordinary galaxy. Due to the power of their influence, and their frequent changes, a time we thought that quasars were relatively low and close rather than distant and powerful objects. The emission of quasars is strongly shifted towards the red, i.e. they move at very high speed of the Milky Way, according to the law of Hubble. Like radio galaxies, some quasars are surrounded by lobes with strong radio emissions.

 

Most of the radio emission of quasars appears to come from a core of some brilliant light years in diameter at most. The radio galaxies and quasars can be detected at great distance because they are radio sources of extreme power. These radio signals from distant sources are slow to reach the Earth, which is why radio astronomers can see the universe as it appears there are more than 10 billion years back in time to the origins of the Universe. They hope to see this famous moment of the first explosion, the Big Bang.

nota: The CFHT is located near the summit of Mauna Kea in Hawaii, at an altitude of 4 204 m.

Image: A quasar is a source of energy the most powerful of the universe, a huge cauldron of incandescent gas, which generates more light than 1 000 galaxies. It is a super massive black hole, a colossal scale as dense a billion suns, seeking a permanent full of stars, 1000 bodies like the Sun per year.

 quasar

100 000 quasars in the universe

    

The nearest quasars are now known to be super massive black holes at the centers of galaxies. Unfortunately, the huge luminosity of quasars allows us to observe at very large distances, it makes the study of their host galaxy difficult.
Indeed, the huge contrast between the bright quasar host galaxy and its much smaller makes it almost impossible to study the latter as soon as its redshift exceeds 0.2 quasars therefore very close to the scale the Universe.
The quasars that formed in the first billion years of the universe are more mysterious, because the nature of the surrounding gas is still unknown.
Studies on the statistical distribution of a range of quasars show that when the universe only a few billion years of existence, the number of intense radiosources was much higher. The most distant quasar observed is 13 billion light-years from Earth. Scientists have identified more than 100 000 quasars observed in the Universe.

 

The nearest is at ≈ 780 million light years away and the farthest to ≈ 13 billion al, to the edge of the observable universe. A quasar is a source of energy the most powerful of the universe, a huge cauldron of incandescent gas, which generates more light than 1 000 galaxies. So this is a super massive black hole, a colossal scale as dense a billion suns, seeking a permanent full of stars, 1000 bodies like the Sun per year.

Image: The quasar 3C 273, in the constellation Virgo, is the brightest ever observed.
Photography taken by the Hubble Space Telescope.

 quasar 3C273

What does a quasar?

    

What is happening near the center of this cluster of galaxies, on the image to the cons?
At first glance, it appears that several strangely elongated galaxies are around five brightest quasars in white on the image.
In fact, a cluster of galaxies acts as a gigantic gravitational lens that distorts and increases the bright objects behind.
The five bright white points near the cluster center are actually images of a single 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 image to watch against that galaxies located in 2H and 4H are actually images of the galaxy.
A third image of this galaxy is about 10H, in the center of the cluster.

 

Image: The observation of the universe is sometimes misleading because a happy chance, we can see many strange and imaginary galaxies, such as colored jewels on the image below against.
The galactic seen by the huge gravitational lens is cataloged SDSS J1004 4112 and is about 7 billion light-years away towards the constellation Leo.

 quasar hst

See also

     
      
      
 
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