排序方式： 共有7条查询结果，搜索用时 15 毫秒
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Zaznobin I. A. Burenin R. A. Lyapin A. R. Khorunzhev G. A. Afanasiev V. L. Grokhovskaya A. A. Dodonov S. N. Eselevich M. V. Uklein R. I. Bikmaev I. F. Khamitov I. M. Gilfanov M. R. Lyskova N. S. Medvedev P. S. Sunyaev R. A. 《Astronomy Letters》2021,47(3):141-149
Astronomy Letters - We present the first results of our program of optical observations for galaxy clusters from the Lockman Hole X-ray survey with the eROSITA telescope onboard the SRG space... 相似文献
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The images of relativistic jets from extragalactic sources produced by gravitational lensing by galaxies with different mass
surface density distributions are modeled. In particular, the following models of the gravitational lens mass distribution
are considered: a singular isothermal ellipsoid, an isothermal ellipsoid with a core, two- and three-component models with
a galactic disk, halo, and bulge. The modeled images are compared both between themselves and with available observations.
Different sets of parameters are shown to exist for the gravitationally lensed system B0218+357 in multicomponentmodels. These
sets allow the observed geometry of the system and the intensity ratio of the compact core images to be obtained, but they
lead to a significant spread in the Hubble constant determined from the modeling results. 相似文献
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T. B. Yanovskaya E. L. Lyskova T. Yu. Koroleva 《Izvestiya Physics of the Solid Earth》2014,50(5):632-640
The dispersion curves of the Rayleigh wave group velocities are constructed along 60 interstation seismic paths in Central Europe based on the cross-correlation function of seismic noise. Together with the previous data (Yanovskaya and Lyskova, 2013), this information was used for reconstructing the three-dimensional distribution of S-wave velocities in the upper mantle of the Carpathian region. In the present work, the previous results are refined by expanding the data set by the additional seismic paths that intersect the Carpathian region and by modifying the procedure for constructing the locally averaged dispersion curves so as to obtain a more compact resolution. The results of the study suggest the complex, multidirectional character of the plate motion in the region. 相似文献
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Calibrating functions for determination of P-wave spectral magnitudes calculated by Duda and Yanovskaya (1994) on the basis of the IASP91 velocity model and the PREM Q-model are verified empirically. For this purpose IRIS broadband records for 120 earthquakes are used, each earthquake having been recorded at about 100 stations. The discrepancies indicate that anelastic absorption assumed in PREM is too high. New calibrating functions are calculated on the basis of the AK135 velocity and anelasticity models (Kennet et al., 1995; Montagner and Kennet, 1996), in which Q in the mantle is higher than in PREM. The verification of the new calibrating functions based on the same observations yields magnitude figures less depending on the epicentral distance. In addition the parameter 2in the Liu-Anderson Q(T) model is estimated, proceeding from the assumption that on the average the radiated spectra comply with the 2-model. The value of 2 was assumed to be 0.1 s in the analysis and its use resulted in the verification of the 2-model for the source spectrum. 相似文献
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Zaznobin I. A. Burenin R. A. Bikmaev I. F. Khamitov I. M. Khorunzhev G. A. Lyapin A. R. Eselevich M. V. Lyskova N. S. Medvedev P. S. Gilfanov M. R. Sunyaev R. A. 《Astronomy Letters》2021,47(2):61-70
Astronomy Letters - We present the results of our spectroscopic redshift measurements for galaxy clusters detected previously from Planck all-sky survey data as well as Sloan Digital Sky Survey and... 相似文献
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The possibility of using lensed relativistic jets on very small angular scales to construct proper models of spiral lens galaxies
and to independently determine the Hubble constant is considered. The system B0218+357 is used as an example to illustrate
that there exists a great choice of model parameters adequately reproducing its observed large-scale properties but leading
to a significant spread in the Hubble constant. The jet image position angle is suggested as an additional parameter that
allows the range of models under consideration to be limited. It is shown that themodels for which the jet image position
angles differ by at least 40° can be distinguished between themselves during observations on very small angular scales. The
possibility of observing the geometric properties of lensed relativistic jets and measuring the superluminal velocities of
knot images on time scales of several months with very long baseline space interferometers is discussed. 相似文献
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The method for surface wave tomography based on the records of ambient seismic noise (Ambient Noise Tomography, ANT) is applied to the data from the East European and West European stations. In order to reduce the effects of the earthquakes at long periods, the cross correlation functions were calculated for the time interval of 2001–2003, when distinct clusters of the earthquakes were absent. Using the local dispersion curves in the range of 10–100 s, we reconstructed the vertical velocity sections at the nodes of the 3° × 3° grid. On the basis on these curves, we calculated the horizontal distributions of S-velocity variations in the upper mantle in the depth interval of 75–275 km and the vertical velocity sections along the profiles across the Vrancea zone and the region of the Baltic and Ukrainian shields. The velocity distribution in the Vrancea zone confirms the subduction of the ancient oceanic plate from the east westwards and the detachment of its bottom part, as hypothesized by some authors. Beneath the Baltic Shield lithosphere, there is a low-velocity zone, which can be interpreted as the asthenospheric layer. It is noted that the velocity distributions beneath the Baltic and Ukrainian shields are similar, which probably points to the genetic relationship between these two structures. 相似文献
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