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461.
Y. N. Gnedin S. D. Buliga N. A. Silant’ev T. M. Natsvlishvili M. Y. Piotrovich 《Astrophysics and Space Science》2012,342(1):137-145
In this paper we demonstrate that the wavelength dependence of polarization degree and position angle allows us to derive the distribution of magnetic field in accretion disc. The polarized radiation arises due to scattering of emission light by electrons in a magnetized optically thick accretion disc. Faraday rotation of polarization plane is taken into consideration. Through wavelength dependence of polarization it is possible to derive the value of the magnetic Prandtl number in the accretion disc plasma. The power law index of the polarization wavelength dependence is related with the radial distribution of magnetic field in an accretion disc. This allows us to test the various models of an accretion disc around the central black hole. 相似文献
462.
The distribution of axial rotation velocities of near-Earth asteroids (NEAs) substantially differs from that of the Main-Belt asteroids by an excess of both quickly and slowly rotating objects. Among the possible causes of this difference is the influence of the solar radiation—the so-called YORP effect—that arises from the absorption of solar energy and its reemission in the thermal range by a rotating body of irregular shape. It is known that the magnitude of this effect depends on the asteroid size and the quantity of received solar energy (the insolation). Analysis of the observational data showed that the mean diameter of NEAs decreases from the middle of the distribution to the edges, i.e., the excess of both slowly (ω ≤ 2 rev/day) and quickly (ω = 8–11 rev/day) rotating objects is formed due to the asteroids with sizes smaller than those in the middle of the distribution, which agrees well with the influence of the YORP effect. Moreover, the dependence of the axial rotation velocity of NEAs on the relative insolation shows that, for the NEAs referred to, both excesses are found in orbits where, on average, they receive 8–10% more solar energy than the NEAs in the middle of the distribution. This result also agrees with the character of the influence of the YORP effect and can be considered as an additional argument in its support. Thus, the study showed that one can infer that the currently available observational data suggest the possible influence of the YORP effect on the axial rotation of the near-Earth asteroids having sizes of D ~ 2 km and less. This is the first attempt to find the influence of the YORP effect on the axial rotation of the NEA family as a whole. 相似文献
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Oceanology - New data on the geological structure and genesis of relict bottom relief forms, objects of underwater cultural heritage, and the structure of bottom sediments in the Baltic Sea were... 相似文献
466.
Kopylov A. I. Kosolapov D. B. Zabotkina E. A. Romanenko A. V. Sazhin A. F. 《Oceanology》2021,61(2):220-232
Oceanology - The distribution of heterotrophic bacteria, viruses, and heterotrophic nanoflagellates was studied in the shelf waters of the East Siberian Sea along the meridional transect from the... 相似文献
467.
Abramova D. Yu. Philippov S. V. Abramova L. M. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(9):1021-1028
Izvestiya, Atmospheric and Oceanic Physics - Geomagnetic data measured by the CHAMP satellite have been used to construct the spatial distribution of the lithospheric magnetic anomaly field in the... 相似文献
468.
This paper summarizes the observations of microseismic emissions by these authors in several areas of the Russian part of the Fennoscandian Shield to assess the potential of microseismicity to determine the present-day activity of local features in the upper part of the geologic medium. We give amplitude–frequency characteristics and the space–time distribution of naturally occurring microseismic events that are hypothesized to be of endogenous origin. We discuss the relationships these characteristics have to the regional geodynamic setting, average dimensions, and petrographic composition of active rock blocks. 相似文献
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