Saturday, November 21, 2009

Astronomers do not believe in his discovery

Team Fermi Space Telescope has found the sky dark galaxies in which no stars, but the smoldering dark matter. As pioneers in the discovery until they believe, and regardless of their test results can not be - where are the candidates, scientists do not raskryvayut.Pomimo great conflict between two cultures - the physicists and poets, put in circulation a Briton, Charles Snow, exactly 50 years ago, for centuries, and there is little conflict dealing exclusively with physics.

Team Fermi Space Telescope has found the sky dark galaxies in which no stars, but the smoldering dark matter.
In mid-2008, an international scientific experiment PAMELA on board Russia's satellite Resurs-DK" found an excess of high-energy positrons in the vicinity of the Sun. They could be born in the spontaneous decay or mutual annihilation of exotic particles, which are expected, and consists of dark matter. Unambiguous interpretation of data is not today, and wrote Someone thinks that it should be dark particles, someone accuses them the appearance of a neutron star near the Sun, some general believes that these are unaccounted systematic errors in the apparatus PAMELA. Many had hoped that the situation will clarify launch space observatory named after Fermi, which registers a very high-energy photons. They could be produced in the interaction of light with the usual high-energy charged particles (so-called inverse Compton scattering). And so the scientists had hoped to clarify the situation with the data PAMELA. Spacecraft WMAP has found an excess of microwave radiation from the galactic center - the so-called "haze WMAP», which remains in the data, if we subtract from them all the known sources of microwaves. One of the most probable explanation for her - synchrotron radiation of energetic electrons, the line wound on the induction of interstellar magnetic fields. Exactly the same electrons using the inverse Compton effect can be produced and high-energy photons, which are able to see Fermi. If the source of energetic positrons and electrons are really particles of dark matter, then they are more likely to be born there where more dark matter. According to modern concepts, such places considered centers of galaxies. Therefore, astronomers eagerly awaiting a special that will see the Fermi towards the center of the Milky Way. Moreover, the allusion to the large number of electrons are astronomers took a few years ago from the apparatus WMAP. Fermi went into orbit in June 2008, and scientific data collection began a few months. The researchers repeated their analysis and have more confidently stated: in addition to haze WMAP» exists and haze Fermi», in which well fits the theory of dissolution or the annihilation of dark matter. There are, however, one important caveat. Even if a large number of electrons and positrons of high energy in the center of the Galaxy there (and no doubt this is less), their origin of dark matter particles still have to prove. In principle, they may be other sources - for example, the shock waves from supernova explosions or the same old neutron stars, which remain on the site of such explosions. Center of the Galaxy must be infested and those and others - simply because there are very many stars, some of which will sooner or later explode. And let the alternative models should be fairly to attract the ears, for many it is still more acceptable explanation than some kind of dark matter there. The discrepancy between the theoretically predicted and observed in reality, the number of dwarf satellites of the Milky Way and other galaxies called the problem of substructure. Its standard solution consists in the fact that dwarf galaxies around us are, but here are the stars in them are not formed. Recent data indicate that such an explanation can really work: the smallest of the newly discovered satellites of our galaxy and indeed consist of only a few hundred stars. But their weight (it can be estimated from the movement of the stars) is much greater. It is assumed that it lies largely in the dark matter. To exclude an alternative to the acceleration of electrons by shock waves, one must look to where supernovae do not explode. In an ideal - a place where there are no stars and dark matter should be. If you believe the theory, such starless dark matter halo really need to surround our galaxy - the theory predicts a dozen times more dwarf galaxies than observed in reality. To find something that does not cover the stars, Elliot Bloom, one of the few pure theorists who are members of the team experiment, Fermi, and his colleague, Ping Wang had perelopatit entire archive of data in search of Fermi extended objects, the gamma radiation which corresponds to the model of dissolution or the annihilation of particles dark matter. In addition, these objects should not overlap with known sources, and the flow of photons from them should not change over time. Bloom and Van found 54 extended sources, allocated over the background of at least four standard deviations. Consistently at each of them, the researchers threw 50 potential "star-free galaxies as inappropriate selected criteria. Remained four criteria are satisfied. Above the background they do not stand out at four, and at least five standard deviations. Nonetheless, Bloom concluded that the new dark dwarfs in these Fermi in the first ten months were not found. The main argument, which leads the scientist - a discrepancy of the spectra of these sources of selected theoretical models of the collapse of dark matter.

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