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141.
We compare the anisotropic properties of the cosmic microwave background (CMB) maps constructed based on the data of NASA’s WMAP (9th year of observations) and ESA’s Planck (2015 release) space missions. In our analysis, we use two two-dimensional estimators of the scatter of the signal on a sphere, which amount to algorithms of mapping the ratio of the scatter in the Northern and Southern hemispheres depending on the method of dividing (specifically, rotating and cutting) the sky into hemispheres. The scatter is computed either as a standard deviation σ, or as the difference between the minimum and maximum values on a given hemisphere. Applying both estimators to the CMB anisotropy datameasured by two spacemissions, Planck and WMAP, we compared the variations of the background at different angular scales.Maps with a resolution of l ≤ 100 show that the division into regions with different levels of statistical anisotropy lies close to the ecliptic plane, and after preliminary removal of the l ≤ 20 harmonics from the CMB data, the anisotropic signal related to the Galaxy begins to dominate. 相似文献
142.
Pulkovo astrometric observations began in the 1840s using the Repsold transit instrument in the prime vertical and Ertel vertical
circle. The first observers on these instruments were W.I. Struve, 1840–1856, and Kh.I. Peters, 1842–1849. In the present
work, we collected and analyzed different series of latitude variations from observations made by M.O. Nuren, B. Wanach, A.A.
Ivanov, I.N. Bonsdorf, and A.Ya. Orlov. In addition, results are given of investigations of a specific behavior of the Chandler
polar motion in this interval, obtained by C. Chandler, Ivanov, Kh. Kimura, Orlov, and N. Sekiguchi. The aim of this paper
is to search for and analyze the earliest series of Pulkovo latitudes, in order to evaluate the possibility of their use to
study the motion of the pole at the maximum available range of observations. Different methods were used to isolate and analyze
the sum of Chandler and annual latitude variations. The annex provides a series of Pulkovo latitude variations for 1840–1848,
which may be used to extend latitude variation back to 1840. 相似文献
143.
L. A. Yakovina Ya. V. Pavlenko K. Abia A. E. Rozenbush 《Kinematics and Physics of Celestial Bodies》2011,27(5):233-248
We determine lithium abundances in atmospheres of three carbon stars from synthetic spectrum fitting in the λλ 668–674 nm
range using the Li I λ 670.8 nm resonance doublet. To produce synthetic spectra, we use a modified list of atomic lines from
the VALD database and three alternative line lists of CN and C2 molecules which are modifications of line lists from the Jorgensen’s website () and from the Kurucz database (1993, CD-ROM nos. 1–23). The spectral lines from these lists were tested by matching synthetic
spectra to observed spectra of the sun, Arcturus, and early R star HD 100764. We perform analysis of the blends involving
the Li I λ 670.8 nm doublet in spectra of N stars AW Cyg and UX Dra. The lithium abundances in HD 100764, AW Cyg, and UX Dra
are estimated to be lgN(Li) ≈ 2, −1.4, and −0.9, respectively. Discrepancies of lithium abundances lgN(Li) obtained with the help of molecular line lists do not seem to exceed 0.2 dex. 相似文献
144.
The possibility of obtaining information about oscillation processes in magnetic flux tubes on the Sun by analyzing the undulating
frequency drift of the zebra pattern in the dynamic spectrum of solar radio emission is discussed. It is shown that the oscillatory
variation in the frequency of zebra stripes can be associated with fast magnetoacoustic (FMA) oscillations in a flux tube,
which lead to oscillations in the magnetic field strength and electron number density. The October 25, 1994 event recorded
by the radio spectrograph of the Astrophysical Institute Potsdam is used as an example to demonstrate the possibility of determining
the parameters of FMA oscillations and the physical conditions in coronal magnetic loops from the observed zebra-pattern characteristics. 相似文献
145.
Yu. V. Glagolevskij G. A. Chountonov A. V. Shavrina Ya. V. Pavlenko 《Astrophysics》2010,53(1):133-146
This is a preliminary study of the star HD 35502. Its magnetic field has been measured in different phases of its period.
Preliminary values of the magnetic field parameters have been obtained based on a central quadrupole model. The effective
magnetic field Be varies over 0-5000 G, the average surface magnetic field ranges over 6300-6700 G, the field at the poles
is Bp=7000 G, and the angle between the quadrupole axis and the axis of rotation is β = 80o. As a first approximation, the
surface helium is concentrated around the (negative) pole and for τ > 1 its abundance is reduced by approximately 2-4 dex,
which confirms the hypothesis of helium diffusion under the action of gravitation and wind in a stable atmosphere. The chemical
elements Si and Cr are concentrated in four spots on the magnetic equator between the magnetic poles, or in a ring coincident
with the magnetic equator; precisely which is not clear at present. 相似文献
146.
M. Ya. Marov A. V. Kolesnichenko K. K. Manuilov V. P. Osipov 《Solar System Research》2010,44(5):393-402
The methodology and the main features of the Thermophob experiment developed for the direct analysis of the thermophysical
properties of the surface of the Martian satellite Phobos from the Phobos-Grunt lander are considered. The methodical and engineering aspects of the measurements are discussed, and the design of the instrument
and the potential of the interpretation of the measurement results with accounting for the theoretical estimates and the data
of the laboratory tests are discussed. 相似文献
147.
Hydrodynamic models of a young binary accreting matter from the remnants of a protostellar cloud have been calculated by the SPH method. Periodic variations in column density in projection onto the primary component are shown to take place at low inclinations of the binary plane to the line of sight. These can result in periodic extinction variations accompanied by brightness variations in the primary. Generally, there can be three periodic components. The first component has a period equal to the orbital one and is attributable to the streams of matter penetrating into the inner regions of the binary. The second component has a period that is a factor of 5–8 longer than the orbital one and is related to the density waves generated in a circumbinary (CB) disk. Finally, the third, longest period is attributable to the precession of the inner CB disk regions. The relationship between the amplitudes of these cycles depends on the model parameters as well as on the inclination and orientation of the binary in space. We show that at a dust-togas ratio of 1: 100 and amass extinction coefficient of 250 cm2 g?1, the amplitude of the V-band brightness variations in the primary component can reach 1 m at a mass accretion rate onto the binary components of 10.8?8 M ⊙ yr?1 and a 10° inclination of the binary plane to the line of sight. We discuss possible applications of the model to young, pre-main-sequence stars. 相似文献
148.
S. P. Pletnev M. V. Cherepanova E. D. Ivanova I. V. Utkin Ya. V. Kuz’min G. S. Burr 《Stratigraphy and Geological Correlation》2010,18(4):450-463
The diversified analysis (data on radiocarbon ages, diatoms, planktonic and benthic foraminifers) of sediments from the central
part of the Sea of Okhotsk (core from a depth of 1186 m) made it possible to define five sedimentary units corresponding to
five marine oxygen-isotope stages MIS 5-MIS 1 (the last 120 ka) and provide their thorough paleontological characteristic,
using different microfossil groups. Microfossil assemblages demonstrate variations in their abundance, distribution of individual
species, and representatives of different ecological groups through the section. 相似文献
149.
A sequence of mineral associations was examined in eclogitized basites of the Krasnaya Guba dike field in the Belomorian Mobile
Belt. Two morphological types of eclogite and eclogite-like rocks were recognized: (1) eclogite rocks that developed after
ferrogabbro dikes and completely replaced these dikes from contact to contact and (2) eclogite-like rocks that developed after
gabbronorites in zones of ductile deformations and shearing. According to data mineral geothermobaromety, both rock types
were formed within temperature and pressure ranges corresponding to high-pressure and high-temperature amphibolite facies
at T = 700 ± 40°C and P = 10.0 ± 0.5 kbar. The peak metamorphic parameters of the host gneisses are analogous. The decompressional stage, which is
unambiguously identified by reaction textures, occurred at 630–660°C and 7.9–8.2 kbar. As the temperature and, first of all,
pressure decreased, the SiO2 activity in the fluid systematically varied. The eclogitization of the basites took place locally in relation to fluid fluxes,
which were restricted to zones of intense deformations, at variable SiO2 activity. The rocks show evidence of two stages of post-eclogite amphibolization. Older amphibolization 1 was coeval with
the late prograde metamorphic stage (T = 650°C, P = 10–11 kbar). Younger amphibolization 2 affected eclogitized basite dikes and unaltered gabbronorites (together with their
host gneisses) over large areas. This process coincided with decompression (T = 580°C, P = 7–8 kbar) and was likely accompanied by the exhumation of deep zones of BMB to upper-middle crustal levels. 相似文献
150.
A. Ya. Bolsunovskii Yu. V. Aleksandrova A. G. Degermendzhi 《Doklady Earth Sciences》2010,434(1):1219-1221
The content of a long-lived technogenic radionuclide 99Tc in the Yenisei within the territory of radioactive effluents of the Rosatom mining chemical combine (MCC) has been studied.
In 2008–2009 the maximal 99Tc content in water was registered near the dumping site of the MCC and came to 33 mBq/l. According to analysis of filtered
water samples, technetium in the Yenisei water is presented as pertechnetate ion (TcO4). When moving away from the MCC downstream, the 99Tc content in water is decreased, which is caused both by dilution of waste water and by 99Tc accumulation by aquatic plants. The 99Tc content in the biomass of the aquatic plant Potamogeton lucens came to 8215 Bq/kg, and the concentration factor (CF) to 8200, which is three times more than the maximal values of the CF of 99Tc by the plants in laboratory conditions (2700). 相似文献