On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: I. Cosmic microwave background radiation     

Anatoliy I. Fisenko  Vladimir Lemberg 《Astrophysics and Space Science》2014,352(1):221-230

Using the explicit form of the functions to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies v ₁≤v≤v ₂ are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60–600 GHz frequency interval at the temperature T=2.72548 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant σ are calculated. In the case of the dipole spectrum, the constants a and σ, and the radiative and thermodynamic properties of the CMB radiation are obtained using the mean amplitude T _amp=3.358 mK. It is shown that the Doppler shift leads to a renormalization of the radiation density constant a, the Stefan-Boltzmann constant σ, and the corresponding constants for the thermodynamic functions. The expressions for new astrophysical parameters, such as the entropy density/Boltzmann constant, and number density of CMB photons are obtained. The radiative and thermodynamic properties of the Cosmic Microwave Background radiation for the monopole and dipole spectra at redshift z≈1089 are calculated.  相似文献   

俄远东、中国东北的构造特点及岩石圈深部的不均一性     

赵春荆  何国琦  段瑞焱 《国土资源》1995,(4)

俄罗斯远东和中国东北前新生代可划分为８个大地构造单元。区域地质、深部地质、地球物理及新构造研究表明，地壳和地幔深部的不均一性反映了该区主要构造单元的深部构成和大地动力学等方面的特点。地热和地磁资料表明，远东地区软流层顶部具有起伏形态的特点，最大深度２００～２５０ｋｍ，浅部仅１００～１４０ｋｍ，松辽盆地７５～１００ｋｍ；在中国东北及亚太过渡带上地幔低速层厚度在０～１００ｋｍ之间变化，计算数据表明，本区地壳厚度为３０～４４ｋｍ，变化幅度为１４ｋｍ。  相似文献   

A cosmological study of the star formation history in the solar neighbourhood     

X. Hernández  Vladimir Avila-Reese  Claudio Firmani 《Monthly notices of the Royal Astronomical Society》2001,327(1):329-338

We use a cosmological galactic evolutionary approach to model the Milky Way. A detailed treatment of the mass aggregation and dynamical history of the growing dark halo is included, together with a self-consistent physical treatment for the star formation processes within the growing galactic disc. This allows us to calculate the temporal evolution of star and gas surface densities at all galactic radii, in particular, the star formation history (SFH) at the solar radius. A large range of cosmological mass aggregation histories (MAHs) is capable of producing a galaxy with the present-day properties of the Milky Way. The resulting SFHs for the solar neighbourhood bracket the available observational data for this feature, the most probable MAH yielding the optimal comparison with these observations. We also find that the rotation curve for our Galaxy implies the presence of a constant density core in its dark-matter halo.  相似文献   

Nonlinear oscillations in star-forming systems     

V. I. Korchagin  P. I. Korchagin  A. D. Ryabtsev 《Astrophysics and Space Science》1988,141(1):55-64

A number of analytically formulated models of star-forming systems which include nonlinear interactions of stars and interstellar medium are considered. It is shown that two conditions are essential for the development of nonlinear oscillations: namely, the induced star formation and the presence of time-delay or strong nonlinearity in interacting star-cloud systems. The three component model with time-delay reproducing the temporal behaviour obtained in numerical simulations by Seidenet al. (1982) is proposed.  相似文献   

Compressible,conductive, steady MHD flow in a gravitational field     

Vladimir Osherovich 《Astrophysics and Space Science》1983,93(2):221-228

The magnetohydrodynamics of a compressible fluid with finite electrical conductivity in a gravitational field is treated analytically. For the case of one ignorable coordinate in cylindrical and Cartesian coordinates the problem is reduced to a scalar partial differential equation. The ideal gas equation of state is considered. For simplicity, the new equation is derived for a two-component motion. The application of this result to mass flow in sunspots is discussed.  相似文献   

The integrable cases of the general spatial three-body problem at third-order resonance     

Vladimir N. Shinkin 《Celestial Mechanics and Dynamical Astronomy》1995,62(4):323-334

For the general three-body problem at third-order resonance an analytical solution is obtained by the use of the Weierstrass functions.  相似文献   

The effect of orbital eccentricity and nodal regression on spin-stabilized satellites     

Vladimir N. Dvornychenko  R. Bruce Gerding 《Celestial Mechanics and Dynamical Astronomy》1977,16(3):263-274

The gyroscopic motion of a spin-stabilized satellite due to gravity gradient torques in a circular orbit has been analyzed to varying degrees in numerous publications. This paper shows that the restriction to a circular orbit is, in fact, not essential and with a slight increase in complexity, noncircular orbits may be treated. More importantly, a uniform regression of the orbital node can also be accounted for. The general results are expressed in closed form using Jacobian elliptic functions. Finally, and this is perhaps most important, certain algebraic integrals of the precession are given which can be used to place limits on the excursions of the spin axis without actually solving for the motion. This allows one to design orientations such that the maximum angle between the orbit normal and spin axis never exceeds a specific amount even though the orbit normal is in precession.  相似文献   

Force-free electromagnetic waves     

Vladimir A. Osherovich  Erast B. Gliner 《Solar physics》1988,117(2):391-397

The time-dependent Force-Free Electromagnetic Field (FFEMF) is studied. In contrast to the case of Force-Free Magnetic Field (FFMF), it is shown that the FFEMF can occur in the form of waves. The FFEMF wave equation is solved in the case of one spatial dimension. Besides a periodical linear FFEMF wave solutions, the existence of solitary wave solutions is demonstrated. The possible application of FFEMF solutions to solar flares is discussed.Work done at the Space Environment Laboratory, NOAA/ERL/SEL, Boulder, CO 80303, U.S.A.  相似文献   

Generation of large-scale structure by ejection of masses from the center of a galaxy     

V. I. Korchagin  V. F. Rakhimov 《Astrophysics》1981,17(2):206-213

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Book reviews     

G. Lomnitz  Vladimir Schenk 《Natural Hazards》1988,1(3):309-310

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