Evidence for pole switching in the magnetic cataclysmic variable BY Camelopardalis     

Paul A. Mason  Gavin Ramsay  Ivan Andronov  Sergey Kolesnikov  Nickolay Shakhovskoy  & Elana Pavlenko 《Monthly notices of the Royal Astronomical Society》1998,295(3):511-518

An analysis of X-ray and optical light curves of the magnetic cataclysmic variable (MCV) BY Cam is presented. This system is one of three MCVs in which the spin period of the white dwarf and the binary orbital period differ by ∼1 per cent. As such these 'BY Cam' stars are important objects with which to probe the field structure of the magnetic white dwarf and ultimately the nature of synchronization of AM Her binaries. We confirm asynchronous rotation of the magnetic white dwarf with respect to the binary. We find evidence that the accretion stream accretes directly on to the white dwarf as in AM Her systems, but further, the stream impacts on to different magnetic poles over the course of the beat period. We present evidence that the optical and hard X-ray light curves modulate in phase, but together they are out of phase with the soft X-ray light curve. We confirm the spin down of the white dwarf which is expected to lead to the synchronization of the spin and orbital periods of BY Cam.  相似文献   

Duration of formation of magmatic system of polyphase Paleozoic alkaline complexes of the central Kola: U-Pb, Rb-Sr, Ar-Ar data     

A. A. Arzamastsev  L. V. Arzamastseva  A. V. Travin  B. V. Belyatsky  A. M. Shamatrina  A. V. Antonov  A. N. Larionov  N. V. Rodionov  S. A. Sergeev 《Doklady Earth Sciences》2007,413(3):432-436

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Early cretaceous cortlandite-pyroxenite-gabbro association of the Upper Amur region: Geochronological and geochemical data     

V. E. Strikha  V. A. Stepanov  N. I. Rodionov 《Doklady Earth Sciences》2006,407(3):469-473

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U‒Pb Age of Sphene and the Petrochemical,Mineralogical, and Geochemical Features of Alkaline Rocks of the Bogdo Complex (Arctic Siberia)     

Dobretsov  N. L.  Zhmodik  S. M.  Lazareva  E. V.  Tolstov  A. V.  Belyanin  D. K.  Surkov  O. N.  Dobretsov  N. N.  Rodionov  N. V.  Sergeev  S. A. 《Doklady Earth Sciences》2019,489(1):1352-1357

Doklady Earth Sciences - In the northern part of the Siberian Platform, east of the Anabar Shield, several massifs of alkaline rocks with carbonatites identified (Tomtor, Bogdo, Promezhutochnyi)...  相似文献   

New zircon ages on the Cambrian–Ordovician volcanism of the Southern Gemericum basement (Western Carpathians,Slovakia): SHRIMP dating,geochemistry and provenance     

Vozárová  Anna  Rodionov  Nickolay  Šarinová  Katarína  Presnyakov  Sergey 《International Journal of Earth Sciences》2017,106(6):2147-2170

International Journal of Earth Sciences - The Southern Gemericum basement in the Inner Western Carpathians, composed of low-grade volcano-sedimentary rock complexes, constitutes a record of the...  相似文献   

El Chichon: The genesis of volcanic sulfur dioxide monitoring from space     

Arlin Krueger  Nickolay Krotkov  Simon Carn 《Journal of Volcanology and Geothermal Research》2008

The 1982 eruption of El Chichon inspired a new technique for monitoring volcanic clouds. Data from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus-7 satellite were used to measure sulfur dioxide in addition to ozone. For the first time precise data on the sulfur dioxide mass in even the largest explosive eruption plumes could be determined. The plumes could be tracked globally as they are carried by winds. Magmatic eruptions could be discriminated from phreatic eruptions. The data from El Chichon are reanalyzed in this paper using the latest version of the TOMS instrument calibration (V8). They show the shearing of the eruption cloud into a globe-circling band while still anchored over Mexico in three weeks. The measured sulfur dioxide mass in the initial March 28 eruption was 1.6 Tg; the April 3 eruption produced 0.3 Tg more, and the April 4 eruptions added 5.6 Tg, for a cumulative total of 7.5 Tg, in substantial agreement with estimates from prior data versions. TOMS Aerosol Index (absorbing aerosol) data show rapid fallout of dense ash east and south of the volcano in agreement with Advanced Very High Resolution Radiometer (AVHRR) ash cloud positions.  相似文献   

An iterative method for constructing equilibrium phase models of stellar systems     

S. A. Rodionov  E. Athanassoula  N. Ya. Sotnikova 《Monthly notices of the Royal Astronomical Society》2009,392(2):904-916

We present a new method for constructing equilibrium phase models for stellar systems, which we call the iterative method. It relies on constrained, or guided evolution, so that the equilibrium solution has a number of desired parameters and/or constraints. This method is very powerful, to a large extent due to its simplicity. It can be used for mass distributions with an arbitrary geometry and a large variety of kinematical constraints. We present several examples illustrating it. Applications of this method include the creation of initial conditions for N -body simulations and the modelling of galaxies from their photometric and kinematic observations.  相似文献   

Stages of the lower crust formation of the Belomorian mobile belt,Kola Peninsula     

Vetrin  V. R.  Lepekhina  E. N.  Paderin  I. P.  Rodionov  N. V. 《Doklady Earth Sciences》2009,425(1):269-273

Doklady Earth Sciences -  相似文献   

Geology and geochronology of neoarchean anorogenic magmatism of the Keivy structure, Kola Peninsula     

V. R. Vetrin  N. V. Rodionov 《Petrology》2009,17(6):537-557

Anorogenic magmatic complexes were formed during protoplatformal evolution of the Keivy structure. This evolution ended with development of aluminous schists, which were derived by deep disintegration and redeposition of the rocks from the lower parts of the sequence and surrounding of the structure. The anorogenic rocks of the region are represented by the following magmatic complexes: gabbro-labradorite-latite-monzonite-granites; ophitic gabbro and gabbrodiabases; quartz syenite-alkaline granites; alkaline and nepheline syenites. The magmatic activity of this period, starting from the emplacement of gabbrolabradorite massifs and ending with alkaline and nepheline syenite bodies, was caused by ascent of mantle asthenolith, which destructed the Earth’s crust basement in this area. The anorogenic magmatism of the Keivy structure lasted for no more than few or few tens of million years. The granitoid subcomplex of the gabbro-labradorite-latite-monzonite-granite complex is dated at 2674 ± 6 Ma, which is comparable with an age of alkaline granites of the Ponoy and Beliye Tundry massifs (2673 ± 6 Ma). The considered complexes are separated in time by intrusion of amphibole-biotite plagiomicrocline granites with an age of 2667 ± 8 Ma. Gabbrolabradorites of the Shchuch’e Ozero and Tsaga massifs have close ages (2663 ± 7 and 2668 ± 10 Ma, respectively, Bayanova, 2004), but were formed earlier than granitoids (Bayanova, 2004). Formation of alkaline syenites of the Sakharijok I Massif, which finalized the Neoarchean anorogenic magmatism of the region, falls in the same interval. During Paleoproterozoic transformations, the rocks of the Keivy structure were sheared and uranium was introduced in the contact zones of the alkaline granite massifs, which caused formation of palingenetic melts and subsequent formation of pegmatites in the outer contact zones of the granite bodies.  相似文献   

Main formation stages of the paleoarchean crust in the Kukhtui Inlier of the Okhotsk Massif     

V. K. Kuz’min  V. A. Glebovitskii  N. V. Rodionov  A. V. Antonov  E. S. Bogomolov  S. A. Sergeev 《Stratigraphy and Geological Correlation》2009,17(4):355-372

Based on U-Pb dating (SHRIMP-II) of euhedral zircon cores from hypersthene-plagioclase granulites of the Kukhtui Inlier (Okhotsk Massif), their igneous protholith of the basic composition is estimated to be Archean in age (3.7 Ga), which is confirmed by the Sm-Nd measurements. Subsequent tectonothermal events are established to occur 3.3–3.2, 2.8–2.7, and 1.9–1.8 Ga ago.  相似文献