Wednesday, October 10, 2012

Songs of the Big Bang

It is known that the universe after the Big Bang has undergone swift increase, during which its volume increased to a staggering 80-degree! Universe and then continued its extension, but the recent increase in size was accelerated, resulting in a region of the universal signal extended outside.

For "writing" a detailed history of the expansion in the boss method, called "baryon acoustic oscillations-oscillations" (BAO). Physicists call ordinary baryons and all the usual matter.

Quite unexpectedly they found that the galactic density peaks defined sound pressure, hence the name of the method.

Like any explosion, the Big Bang, which led to the birth of the universe, "roared" at full power. Propagation of sound waves that long blast occurred in a hot source plasma "soup" in which any regular density peaks. After about 380 thousand years after the Big Bang "soup" cool enough to slow down as a result did the first proton-electron pairs, or hydrogen atoms. Invisible dark matter, too, was part of the broth and the photons of light have gone their own way.

It can be assumed that the recession of galaxies has until recently been fairly uniform, so the distance to the object, and also speaks about his age. Helps and redshift of light waves, telling us about the age of a particular corner of the universe. The physics of this unique phenomenon is the fact that the expansion is proportional to "stretch" of the space: the same light wavelength increase in its path as it contributes to tension and an increase in length respectively. Red edge of the visible spectrum has wavelengths nearly half times more than the blue.

With Bossi have already precisely determined the position of 327,349 of massive galaxies with a redshift of 0.7 that is still very close to the Earth. The mean bias is 0.57, which corresponds to a distance of 6 billion light-years. The achieved accuracy of the range of 1.7%, or about 2 megaparsecs. Anything like optical astronomy cannot give.

BOSS can also talk about violations of the red shift, which the researchers hope to test gravity. Tests show the speed of joint motion galaxies neighbors, which leads to the formation of clusters. It is possible that it will be another confirmation of Einstein's general theory of relativity.

Now the definition of the expansion depends only on the definition of the red shift, which is the less accurate the farther away the deleted object. Statistical analysis of the red shift of hundreds of thousands of galaxies revealed the presence of local variations of the Hubble expansion rate, as well as indicators of gravity at a distance of 100 million light-years, more accurate than those obtained by measuring the distance from the Earth to the Moon.

"Maintenance" in the space provided does not mean the death of ground-based telescopes. On the contrary, the data are compared with those obtained by the Sloan telescope with a mirror diameter of 2.5 meters, which is located in the town of Apache, New Mexico. Interest to the telescope increased particularly when it installed a new fiber spectrograph having a half more fiber than the previous versions, to monitor it for the Galaxy.

In just 15 minutes of observation telescope time to "cover" the three degrees of the sky, while on thousands of fibers running from the focal plane of the mirror, the computer is receiving digital information. The spectrograph is designed in such a way that each of the fibers ensures a distant, but still bright galaxy that has already "lit up" in previous cases. To increase the area of ​​monitoring and permit new spectrograph equipped with secondary camera captures images in the red and blue spectral regions.

 Of New Mexico, the data being sent for treatment in Berkeley, not far from San Francisco. The information is then used to generate new galactic catalogs describing today more than a million of them. In March, reported the discovery of exotic, like "Spider" and "Diamond". Bossi results are presented in two major reviews that were published in the prestigious journal Monthly Notices of the Royal Astronomical Society.

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