Dynamics of viscous universe     

Andrzej Woszczyna  Wieslaw Betkowski 《Astrophysics and Space Science》1982,82(2):489-493

The dynamics of the viscous Robertson-Walker universe is presented using the phase variables method. Connection between violence of the strong energy condition and the behaviour of the Universe near the singularity is discussed.  相似文献   

Hamiltonian formalism for Euler parameters     

Andrzej J. Maciejewski 《Celestial Mechanics and Dynamical Astronomy》1985,37(1):47-57

The Euler-Poinsot equations of rigid body motion are considered. The Euler parameters attitude parametrization is assumed. The Hamiltonian form of these equations is obtained. Two different solutions are shown. A short discussion of free motion in this new treatment is also given.  相似文献   

About stability of libration points in the restricted photogravitational three body problem     

Krzysztof Goździewski  Andrzej J. Maciejewski  Zuzanna Niedzielska 《Celestial Mechanics and Dynamical Astronomy》1991,52(2):195-201

Nonlinear stability of the triangular libration point in the photogravitational restricted three body problem was investigated in the whole range of the parameters. Some results obtained earlier are corrected. The method for proper determination of cases when stability cannot be determined by four order terms of the hamiltonian was proposed.  相似文献   

The creation of magnetic monopoles in outer gaps of pulsars     

Andrzej K. Drukier 《Astrophysics and Space Science》1981,74(1):245-248

The production of magnetic monopoles-antimonopoles pairs is expected in the interactions of highly energetic particles in the outer gaps of a pulsar. We estimate upper limit for production of monopoles withm _g 10⁴ GeV _c ^–2 ine ⁺ e ^– interactions of the order _ee 10^–32 cm^–2.  相似文献   

Hot accretion discs with thermal Comptonization and advection in luminous black hole sources     

Andrzej A. Zdziarski 《Monthly notices of the Royal Astronomical Society》1998,296(4):L51-L55

We solve for the structure of a hot accretion disc with unsaturated thermal Comptonization of soft photons and with advection, generalizing the classical model of Shapiro et al. The upper limit on the accretion rate due to advection constrains the luminosity to ≲ 0.15 y^3/5 α^7/5 of the Eddington limit, where y and α are the Compton and viscosity parameters, respectively. The characteristic electron temperature and Thomson optical depth of the inner flow at accretion rates within an order of magnitude of that upper limit are ∼ 10⁹ K and ∼ 1, respectively. The resulting spectra are then in close agreement with the X-ray and soft γ-ray spectra from black hole binaries in the hard state and Seyferts. At low accretion rates, bremsstrahlung becomes the dominant radiative process.  相似文献   

Broad-band X-ray/γ-ray spectra and binary parameters of GX 339–4 and their astrophysical implications     

Andrzej A. Zdziarski  Juri Poutanen  Joanna Mikolajewska  Marek Gierli&#;ski  Ken Ebisawa  & W. Neil Johnson 《Monthly notices of the Royal Astronomical Society》1998,301(2):435-450

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Periodic rotations of a rigid body located at the libration point     

Andrzej J. Maciejewski  Zuzanna Niedzielska 《Celestial Mechanics and Dynamical Astronomy》1990,49(1):31-42

Periodic rotations of a rigid body close to the flat motions were found. Their orbital stability was investigated. Analysis was done up to second order of the small parameter. It was proved that solutions found are orbitally stable except of the third order resonance case. This resonance do not appear if terms up to the first order of small parameter are considered only.  相似文献   

A model of the gravitational field of Amalthea     

Krzysztof Goździewski  Andrzej J. Maciejewski  Philip J. Stooke 《Earth, Moon, and Planets》1994,64(3):243-264

Utilizing the topographic model of Jovian moon Amalthea (Stooke, 1994) and supposing that its mass density is constant we derived its basic geometrical and dynamical characteristics. For calculations the harmonic model of topography of the degree and order 18 was selected. The model appears to fit the entire surface to a mean accuracy of a few hundred meters, except in the regions localized around longitudes 0° and 180°. On the basis of the harmonic expansion of the topography we estimated the volume (V = 2.43 ± 0.02 km³) and the mean radius of topographyr ₀ = (79.7 ± 0.2) km. Generalized moments of inertia up to the order 2, principal moments of inertia and orientation of the principal axes with respect to the original reference frame were also calculated. The results show that although Amalthea has extremely irregular shape it may be treated dynamically as an almost symmetric body (B C). Finally, the set of the Stokes coefficients up to the degree and order 9 was evaluated. The results are verified by direct numerical integration.  相似文献   

Differential calibration of seismometers for measurement of rotation and strain     

Jan Wiszniowski  Marian Hościłowicz  Andrzej Skrzyński  Jerzy Suchcicki  Krzysztof P. Teisseyre 《Acta Geophysica》2008,56(2):391-407

A method of correcting the seismometers’ responses discrepancy for differential measurements of strains and rotations in the seismic far field is proposed. The method concerns differential calibration of the whole seismometers’ array by electric current. A model of corrective filtering of the obtained differential signals in the Z domain is given. Two methods of the filter parameters’ estimation are introduced; they are based on the seismometers response to the calibration. A practical test of the methods — an analysis of a recorded seismic event — is added. Significant reduction of differences between simultaneous seismic recordings was obtained, which is interpreted as cleaning of differential signal from spurious elements.  相似文献   

Book Review
Fronts, Waves and Vortices in Geophysical Flows, by Jan-Bert Flór (ed.), Springer, 2010; ISBN: 978-3-642-11586-8     

Andrzej Icha 《Pure and Applied Geophysics》2011,168(10):1901-1902

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