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Wednesday, October 3, 2012

Solve the mystery of the missing gas clouds, quasars


Scientists have been able to unpick the mystery arise just a few years of disappearance in 19 quasars gas clouds.

The internal structure of quasars - the ancient galaxies, the luminosity of which are so high that they can be confused with the nearby bright star - has interesting features. When approaching the central black hole accretion disk galaxies substance strongly heated and emits more light than the rest of the stars of the galaxy together. Powerful wind of charged particles generated by the heated gas, thus can take a portion of the incident with the black hole matter.

When the radiation coming from the center of the quasar passes through a cloud formed from a quasar winds entrained gas, the light is absorbed at certain wavelengths corresponding to the elemental composition of gas clouds. The absorption lines in the spectrum of light that enters the earthly telescopes, expanded due to the Doppler Effect, produced when the light moving at high velocity gas, so they are called "broad absorption lines." Width of this line determines the speed of the wind of the quasar.

Astronomers Nurtay Filits Ak (Nurten Filiz Ak) and Neil Brandt (Niel Brandt) of the University of Pennsylvania (USA) examined 582 quasar with broad absorption lines and found that 19 of these gas clouds were gone for three years. This fact has allowed scientists to determine that the cloud of gas a typical quasar with broad absorption lines is in the sight of all of our 100 years, after which it disappears, being completely "blown away" quasar wind.

Thus scientists have discovered that the processes in ancient quasars located on us for billions of light years away, could pass for just one hundred years - in astronomical terms a tiny amount of time.

The study was presented in the journal The Astrophysical Journal.

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