排序方式: 共有63条查询结果,搜索用时 31 毫秒
51.
52.
V.?P.?ReshetnikovEmail author S.?S.?Savchenko A.?V.?Moiseev O.?V.?Egorov 《Astronomy Letters》2017,43(12):812-819
Based on SDSS data and spectroscopic observations with the 6-m BTA telescope at SAO RAS, we have studied the galaxy SDSS J170745+302056. By the set of its characteristics— an exponential brightness distribution, a central stellar disk surface brightness μ0(B) = 23m. 25/—, blue colors, a low metallicity, and a moderate star formation rate—this galaxy belongs to typical low-surfacebrightness spiral galaxies. The exponential scale length of the galaxy’s disk is ≈3 kpc, while its optical diameter exceeds 20 kpc. SDSS J170745+302056 is a member of a group of five galaxies and possibly interacts with the galaxy UGC 10716. The existence of a large low-surface-brightness galaxy in such a dense environment is very unusual. 相似文献
53.
Savchenko M. I. Vatagin P. V. Dmitriev P. B. Ogurtsov M. G. Kruglov E. M. Lazutkov V. P. Skorodumov D. V. Shishov I. I. 《Geomagnetism and Aeronomy》2020,60(7):936-941
Geomagnetism and Aeronomy - The paper presents the results of processing of data on the soft X-ray solar radiation obtained by the PINGVIN-M instrument aboard the KORONAS-FOTON spacecraft in July... 相似文献
54.
Hagen-Thorn V. A. Morozova D. A. Savchenko S. S. Hagen-Thorn E. I. Milanova Yu. V. Shalyapina L. V. Vasil’ev A. A. 《Astronomy Reports》2021,65(12):1233-1245
Astronomy Reports - We present and analyze the monitoring results of the blazar 1156+295 in radio, optical, and gamma ranges in 2005–2020. After a long period of relative quietness at the end... 相似文献
55.
D. R. Zozulya E. E. Savchenko K. Kullerud E. K. Ravna L. M. Lyalina 《Geology of Ore Deposits》2010,52(8):843-851
Unusual ultrapotassic dikes were recently found on the Kvalöya Island in Northern Norway. The dikes crosscutting granites 1.8 Ga in age are 0.1–1.0 m thick and consist of phlogopite phenocrysts in a fine-grained groundmass of K-magnesioarfvedsonite, orthoclase, apatite, and secondary chlorite. According to the composition of the rock-forming minerals (4.5–6.0 wt % K2O and 0.7–3.5 wt % TiO2 in magnesioarfved-sonite, 1.6–3.6 wt % FeO in orthoclase, 9.2–10.7 wt % Al2O3 and 2.1–2.6 wt % TiO2 in phlogopite) and its bulk chemical composition (K/Na = 2.3–2.9, K/Al = 1.0–1.2, (Na + K)/Al = 1.4–1.7, Mg# V = 65–73, (La/Yb) n = 100–140, 3.2–4.0 wt % TiO2, 0.55–1.47 wt % BaO, 2.5–3.0 wt % P2O5, 2650–3000 ppm Zr, 900–1260 ppm REE total, 2300–2500 ppm Sr), the rock corresponds to lamproite of the transitional type. The unique chemical composition of the rock resulted in uncommon Ti-Ba-P accessory mineralization, including baotite Ba4(Ti,Nb)8Si4O28Cl (up to 5 vol %), Sr-apatite (5–7 vol %), and previously unknown Na-Mg-Ba phosphate. Baotite forms anhedral elongated and isometric grains 10–500 μm in size. It is characterized by low Nb (0.03–0.05 f.c.); admixtures of K (0.04–0.12 f.c.) and Sr (0.04–0.07) replacing Ba and Fe (0.01–0.03 f.c.); and Al (0.03–0.04 f.c.) substituting Ti. Euhedral elongated zonal apatite crystals are extremely enriched in SrO (8–12 wt %) and REE2O3 + Y2O3 (6–9 wt %) in the marginal zone. Na-Mg-Ba phosphate occurs as prismatic grains 10–100 μm in size. The atomic ratio of its major cations Na: Mg: Ba: P ~ 2: 1: 1: 2 corresponds to the conventional formula Na2MgBa(PO4)2; the mineral contains Sr, Mn, Fe, Ca, Si, and Al admixtures. 相似文献
56.
V. P. Smagin S. V. Semkin V. N. Savchenko 《Izvestiya Atmospheric and Oceanic Physics》2013,49(5):541-547
The electric and magnetic field and electric charges at the medium interface induced by a two-dimensional marine surface and internal waves are considered. The influence of the magnetic permeability and electric conductivity of the bottom rocks on the induced fields is analyzed. 相似文献
57.
Yu. A. Izrael V. M. Zakharov N. N. Petrov A. G. Ryaboshapko V. N. Ivanov A. V. Savchenko Yu. V. Andreev Yu. A. Puzov B. G. Danelyan V. P. Kulyapin 《Russian Meteorology and Hydrology》2009,34(5):265-273
Results of a field experiment on studying solar radiation passing in the visible wavelength range are described with the model aerosol media created in the surface atmosphere. High-efficiency thermocondensation generators were used for creating model aerosol media. The index of refraction and an average size of the aerosol particles formed are close to those characteristic of the natural stratospheric aerosol. The composition and technical characteristics of the equipment complex used in the experiments to control aerosol optical and microphysical parameters and meteorological conditions of the experiment are considered. The Gaussian model of impurity dispersion in the boundary layer is used for the analysis and interpretation of measurement results. It is found that with a number concentration of aerosol particles of ~102–103 cm?3 (which corresponds to the aerosol density in the deposited layer of about 1–10 mg/m2 with the layer thickness along the ray path of about 100 m) the solar radiation attenuation with artificial aerosol layers accounts for 1 to 10%. Model estimates are in satisfactory agreement with the measurement results. 相似文献
58.
Alexey Boyarsky Dmytro Iakubovskyi Oleg Ruchayskiy Vladimir Savchenko 《Monthly notices of the Royal Astronomical Society》2008,387(4):1361-1373
We derive constraints on the parameters of the radiatively decaying dark matter (DM) particle, using the XMM–Newton EPIC spectra of the Andromeda galaxy (M31). Using the observations of the outer (5–13 arcmin) parts of M31, we improve the existing constraints. For the case of sterile neutrino DM, combining our constraints with the latest computation of abundances of sterile neutrinos in the Dodelson–Widrow (DW) scenario, we obtain the lower mass limit m s < 4 keV , which is stronger than the previous one m s < 6 keV , obtained recently by Asaka, Laine & Shaposhnikov. Comparing this limit with the most recent results on Lyman α forest analysis of Viel et al. ( m s > 5.6 keV ), we argue that the scenario in which all the DM is produced via the DW mechanism is ruled out. We discuss, however, other production mechanisms and note that the sterile neutrino remains a viable candidate for DM, either warm or cold. 相似文献
59.
The layered model of the marine environment, including the atmosphere, two seawater layers with different conductivity and density, and the bottom rock layer, has been considered. The geomagnetic field variations, generated by internal and surface waves with different frequency and propagation direction, have been found in the scope of this model. The effect of magnetic permeability and electric conductivity of bottom rocks on induced magnetic field has been taken into account. The transfer functions and spectral densities of these variations have been analytically determined and numerically estimated. 相似文献
60.