36 research outputs found

    Familon Model of Dark Matter

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    If the next fundamental level of matter occurs (preons) then dark matter must consist of familons containing a "hot" component from massless particles and a "cold" component from massive particles. During evolution of the Universe this dark matter was undergone to late-time relativistic phase transitions temperatures of which were different. Fluctuations created by these phase transitions have had a fractal character. In the result the structurization of dark matter (and therefore the baryon subsystem) has taken place and in the Universe some characteristic scales which have printed this phenomenon arise naturally. Familons are collective excitations of nonperturbative preon condensates which could be produced during more early relativistic phase transition. For structurization of dark matter (and baryon component) three generations of particles are necessary. The first generation of particles has produced the observed baryon world. The second and third generations have produced dark matter from particles which have appeared when symmetry among generations was spontaneously broken.Comment: 12 page

    Cosmology of Vacuum

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    Shortly the vacuum component of the Universe from the geometry point of view and from the point of view of the standard model of physics of elementary particles is discussed. Some arguments are given to the calculated value of the cosmological constant (Zeldovich approximation). A new component of space vacuum (the gravitational vacuum condensate) is involved the production of which has fixed time in our Universe. Also the phenomenon of vacuum selforganization must be included in physical consideration of the Universe evolution.Comment: 8 page

    The Effect of 53 micron IR Radiation on 18 cm OH Megamaser Emission

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    OH megamasers (OHMs) emit primarily in the main lines at 1667 and 1665 MHz, and differ from their Galactic counterparts due to their immense luminosities, large linewidths and 1667/1665 MHz flux ratios, which are always greater than one. We find that these maser properties result from strong 53 micron radiative pumping combined with line overlap effects caused by turbulent linewidths of about 20 km/s; pumping calculations that do not include line overlap are unreliable. A minimum dust temperature of about 45 K is needed for inversion, and maximum maser efficiency occurs for dust temperatures in the range 80 - 140 K. We find that warmer dust can support inversion at lower IR luminosities, in agreement with observations. Our results are in good agreement with a clumpy model of OHMs, with clouds sizes about 1 pc and OH column densities about 5e16 cm^2, that is able to explain both the diffuse and compact emission observed for OHMs. We suggest that all OH main line masers may be pumped by far-IR radiation, with the major differences between OHMs and Galactic OH masers caused by differences in linewidth produced by line overlap. Small Galactic maser linewidths tend to produce stronger 1665 MHz emission. The large OHM linewidths lead to inverted ground state transitions having approximately the same excitation temperature, producing 1667/1665 MHz flux ratios greater than one and weak satellite line emission. Finally, the small observed ratio of pumping radiation to dense molecular gas, as traced by HCN and HCO+^+, is a possible reason for the lack of OH megamaser emission in NGC 6240.Comment: Accepted to ApJ, 26 pages including 1 table and 7 figure
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