Search

This paper addresses the scientific and technical prospects and potential directions for the development of subterahertz astronomy in the Russian Federation. The concept of creating subterahertz instruments in the form of a universal compact antenna array for placement on the territory of the Russian Federation is proposed. It is possible to implement several space projects in the subterahertz range using such an antenna array, including a space interferometer and a telescope on the surface of the Moon. Ground-based compact antenna arrays will be able to act as a support for the very long baseline interferometer mode of the Millimetron observatory. [ABSTRACT FROM AUTHOR]

A simple model of spherical dark matter haloes is proposed in terms of two structure functions. In the framework of this model, we analysed the properties of 450 000 simulated haloes with masses M vir > 1011 M⊙. We compared the mean characteristics of simulated haloes with the corresponding characteristics of 641 galaxies and found that the basic characteristics of the two populations are similar but that their probability distribution functions are different. This disagreement may be caused by technical factors such as the halo identification algorithm, which does not reproduce the observed dark matter haloes correctly. [ABSTRACT FROM AUTHOR]

The extragalactic background radiation produced by distant galaxies emitting in the far infrared limits the sensitivity of telescopes operating in this range due to confusion. We have constructed a model of the infrared background based on numerical simulations of the large-scale structure of the Universe and the evolution of dark matter halos. The predictions of this model agree well with the existing data on source counts. We have constructed maps of a sky field with an area of 1 deg directly from our simulated observations and measured the confusion limit. At wavelengths 100-300 μm the confusion limit for a 10-m telescope has been shown to be at least an order of magnitude lower than that for a 3.5-m one. A spectral analysis of the simulated infrared background maps clearly reveals the large-scale structure of the Universe. The two-dimensional power spectrum of these maps has turned out to be close to that measured by space observatories in the infrared. However, the fluctuations in the number of intensity peaks observed in the simulated field show no clear correlation with superclusters of galaxies; the large-scale structure has virtually no effect on the confusion limit. [ABSTRACT FROM AUTHOR]

The properties of the aperiodic variability in X-ray binaries with black holes are considered. The power spectra of the luminosity variability for a flat accretion disk that is an emission source with a powerlaw energy spectrum have been modeled. At low frequencies the derived power spectrum has the form of a power law with a slope ϱ ≈ −1 and a cutoff at a frequency corresponding to the characteristic frequency of fluctuations at the inner disk edge; at higher frequencies the power spectrum has a complex form. The high-frequency variability is suppressed due to the arrival time delays of photons emerged in different parts of the disk. The presence of azimuthal accretion rate fluctuations in the disk and the disk surface brightness nonuniformity in the observer's imaginary plane caused by the relativistic effects give rise to an additional variability component at frequencies ∼ 200 Hz. [ABSTRACT FROM AUTHOR]