188 research outputs found

    The local dust foregrounds in the microwave sky: I. Thermal emission spectra

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    Analyses of the cosmic microwave background (CMB) radiation maps made by the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed anomalies not predicted by the standard inflationary cosmology. In particular, the power of the quadrupole moment of the CMB fluctuations is remarkably low, and the quadrupole and octopole moments are aligned mutually and with the geometry of the Solar system. It has been suggested in the literature that microwave sky pollution by an unidentified dust cloud in the vicinity of the Solar system may be the cause for these anomalies. In this paper, we simulate the thermal emission by clouds of spherical homogeneous particles of several materials. Spectral constraints from the WMAP multi-wavelength data and earlier infrared observations on the hypothetical dust cloud are used to determine the dust cloud's physical characteristics. In order for its emissivity to demonstrate a flat, CMB-like wavelength dependence over the WMAP wavelengths (3 through 14 mm), and to be invisible in the infrared light, its particles must be macroscopic. Silicate spheres from several millimetres in size and carbonaceous particles an order of magnitude smaller will suffice. According to our estimates of the abundance of such particles in the Zodiacal cloud and trans-neptunian belt, yielding the optical depths of the order of 1E-7 for each cloud, the Solar-system dust can well contribute 10 microKelvin (within an order of magnitude) in the microwaves. This is not only intriguingly close to the magnitude of the anomalies (about 30 microKelvin), but also alarmingly above the presently believed magnitude of systematic biases of the WMAP results (below 5 microKelvin) and, to an even greater degree, of the future missions with higher sensitivities, e.g. PLANCK.Comment: 33 pages, 9 figures, 1 table. The Astrophysical Journal, 2009, accepte

    COMPARATIVE ANALYSIS OF THE FREQUENCY OF CYTOGENETIC ABNORMALIES IN THE ROOT APICAL MERISTEM OF SPRING BARLEY (<i>HORDEUM VULGARE </i> L.) CULTIVAE SEEDLINGS, CONTRASTING IN THEIR LEAD TOLERANCE

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    Cell division activity, frequencies and spectra of cytogenetical abnormalities were studied in the root apical meristem cells of spring barley seedlings (Hordeum vulgare L.). Comparative analysis of aberration frequencies in cells of most sensitive or tolerant barley cultivars was made. Sensitive and tolerant cultivars of spring barley were chosen by testing of lead influence on 100 barley cultivars from the VIR collection. Significant differences between groups of sensitive and tolerant cultivars were shown in indexes received on intact seedlings: frequencies of aberrant cells (FAC), frequency of cytogenetical abnormalities on a dividing cell (FADC), frequency of cytogenetical disturbances on a cell with cytogenetical abnormalities (FAAC). Mechanisms of tolerance to lead and HM were discussed

    CAREER-GUIDANCE AND DIGITALIZATION AS LINKS OF ONE PROBLEM

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    The methods of work on professional information distribution, professional enlightenment, professional selection, professional education, professional social adaptation are revealed. Within the conditions of worldwide transition to digital economy the reevaluation of socio-economic situations occurs which has an eect on education sector, its relation to society, labour market, culture, a human being and, as a result, economic, moral, spiritual potential of society and civilization as a whole. The value system of the choice of the place of work and study by individuals, the motives for the choice of professional activity are specied

    GRB Sky Distribution Puzzles

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    We analyze the randomness of the sky distribution of cosmic gamma-ray bursts. These events are associated with massive galaxies, spiral or elliptical, and therefore their positions should trace the large-scale structure, which, in turn, could show up in the sky distribution of fluctuations of the cosmic microwave background (CMB). We test this hypothesis by mosaic correlation mapping of the distributions of CMB peaks and burst positions, find the distribution of these two signals to be correlated, and interpret this correlation as a possible systematic effect.Comment: 12 pages, 16 figures, 1 tabl

    Dominant Multipoles in WMAP5 Mosaic Data Correlation Maps

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    The method of correlation mapping on the full sphere is used to study the properties of the ILC map, as well as the dust and synchrotron background components. An anomalous correlation of the components with the ILC map in the main plane and in the poles of the ecliptic and equatorial coordinate systems was discovered. Apart from the bias, a dominant quadrupole contribution in the power spectrum of the mosaic correlation maps was found in the pixel correlation histogram. Various causes of the anomalous signal are discussed.Comment: 10 pages,11 figure

    Can residuals of the Solar system foreground explain low multipole anomalies of the CMB ?

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    The low multipole anomalies of the Cosmic Microwave Background has received much attention during the last few years. It is still not ascertained whether these anomalies are indeed primordial or the result of systematics or foregrounds. An example of a foreground, which could generate some non-Gaussian and statistically anisotropic features at low multipole range, is the very symmetric Kuiper Belt in the outer solar system. In this paper, expanding upon the methods presented by Maris et al. (2011), we investigate the contributions from the Kuiper Belt objects (KBO) to the WMAP ILC 7 map, whereby we can minimize the contrast in power between even and odd multipoles in the CMB, discussed discussed by Kim & Naselsky (2010). We submit our KBO de-correlated CMB signal to several tests, to analyze its validity, and find that incorporation of the KBO emission can decrease the quadrupole-octupole alignment and parity asymmetry problems, provided that the KBO signals has a non-cosmological dipole modulation, associated with the statistical anisotropy of the ILC 7 map. Additionally, we show that the amplitude of the dipole modulation, within a 2 sigma interval, is in agreement with the corresponding amplitudes, discussed by Lew (2008).Comment: 24 pages, 9 figures, 5 tables. Matches version in JCA

    Verification of high-energy transport codes on the basis of activation data

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    Nuclide production cross sections measured at ITEP for the targets of nat-Cr, 56-Fe, nat-Ni, 93-Nb, 181-Ta, nat-W, nat-Pb, 209-Bi irradiated by protons with energies from 40 to 2600 MeV were used to estimate the predictive accuracy of several popular high-energy transport codes. A general agreement of the ITEP data with the data obtained by other groups, including the numerous GSI data measured by the inverse kinematics method was found. Simulations of the measured data were performed with the MCNPX (Bertini and ISABEL options), CEM03.02, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, and CASCADE.07 codes. Deviation factors between the calculated and experimental cross sections have been estimated for each target and for the whole energy range covered by our measurements. Two-dimensional diagrams of deviation factor values were produced for estimating the predictive power of every code for intermediate, not measured masses of nuclei-targets and bombarding energies of protons. Further improvements of all tested here codes are recommended. In addition, new measurements at ITEP of nuclide yields from a 208-Pb target irradiated by 500 MeV protons are presented. A good agreement between these new data and the GSI measurements obtained by the inverse kinematics method was foundComment: 31 pages, 18 figures, 6 tables, only pdf, LANL Report LA-UR-11-02704, Los Alamos (2011), submitted to Phys. Rev.
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