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The effect of a strong magnetic field on neutron stars or white dwarfs is calculated for Thomson scattering in a strong magnetic field with radiation damping. The Stokes's parameters for the scattered radiation are computed explicitly in terms of the state of polarization of the incident wave, the electrocyclotron frequency, the angle of incidence, and the angle of scattering. The criterion for the magnetic field to substantially affect the Stokes's parameters is that the photon frequency be less than the electrocyclotron frequency. The effects of classical radiation damping are explicitly taken into account by using the Abraham-Lorentz equation. The corresponding quantum mechanical treatment for Compton scattering in a relativistic electron gas is now under investigation. 相似文献
2.
The effect of finite thickness on the properties of disk galaxies is calculated on the basis of a rigorous mathematical treatment
in terms of Green function and Bessel Fourier transformation. In our approach, the mass of the galactic halo is determined
by fitting the observed rotation curve with a five-component model. We not only choose a bulge, a thin disk and a halobut
also include a nuclear bulge (i.e. the Galactic Nucleus) and a thick disk. The effect of finite thickness of the disk on both
the radial and vertical self-gravity is considered in detail. The vertical dynamics of this three-dimensional system is also
investigated. 相似文献
3.
The propagation of spiral density waves in a differentially rotating, self-gravitating, magnetoactive and highly flattened disk is investigated by using the asymptotic theory for tightly wound spirals developed by Lin and his collaborators. We adopt the continuum fluid model as the primary basis, and our treatment will be largely analytical. The disk plasma is studied in the frozen field approximation and inhomogenceous magnetic fields in the plane of the disk are considered in detail.In a differentially rotating disk with strong magnetic fields, the field lines will be considerably distorted and the mutual influence of magnetic fields and differential rotation is by no means obvious.In this paper we present a new asymptotic dispersion relation for tightly wound spiral density waves with magnetic fields along the spiral armsB
(r). The effects of the magnetic fields lead to such terms likek
2(a
2 +V
A
2
), wherek is the wave number,a represents the speed of sound,V
A = (B
2/4)1/2 is the Alfvén speed,B denotes the field strength, and is the plasma density. These terms depict the well-known magnetoacoustic waves and could have been anticipated without a detailed computation. However the interaction of magnetic fields and differential rotation may give rise to other significant terms which are not so easy to foresee.We also present a more exact local dispersion relation by using the WKB approximation and study the effects of magnetic fields on the growth rate through the parametersQ andJ defined in the literature.Although the effects of the magnetic fields are rather insignificant for applications to Galactic dynamics, the effects of the magnetic fields are important for applications to star formation and problems related to the solar nebula. 相似文献
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ARIMA time series model building techniques are used to construct fifty-one state gasoline demand models based on monthly data for the period of January, 1975 to July, 1960. Statistically satisfactory models are obtained for all states. Price elasticity estimates are >0 for all states. All but four are statistically significant at the 0.05 level. The significant price elasticity estimates range from ?0.138 to ?0.377, with most clustering about ?0.2. Estimates of state gasoline supply shortages for May, June, and July, 1979 are also presented which range from 0 to 8 percent of normal consumption for the three-month-period. 相似文献
6.
The effect of a strong magnetic field on neutron stars or white dwarfs is calculated for Thomson scattering in a fully ionized collisionless plasma. The Stokes parameters for the scattered radiation are computed explicitly in terms of the state of polarization of the incident wave, the electron-cyclotron frequency, the plasma frequency, the angle of incidence, and the angle of scattering. The effects of the plasma are very insensitive to specific values of ( =
2
p
/2,p denotes the electron plasma frequency) so long as 1, whereas the criterion for the magnetic field to substantially affect the Stokes parameters is that the photon frequency be less than the electron-cyclotron frequency. The effects of classical radiation damping and natural line broadening are briefly mentioned. 相似文献
7.
Qiu-He Peng Zhi-Quan Luo Chih-Kang Chou School of Physics Electronic Information China West Normal University Nanchong Department of Astronomy Nanjing University Nanjing Department of Physics Sichuan University Chengdu National Astronomical Observatories Chinese Academy of Sciences Beijing 《中国天文和天体物理学报》2006,(3)
Considering neutron star heating by magnetic dipole radiation from 3PF2 super-fluid neutron vortices inside the star, we propose a neutron phase oscillation model between the normal neutron Fermi fluid and the 3PF2 superfluid neutron vortices at the transition temperature of T_(trans) = (2-3)×108 K. With this model we can qualitatively explain most of the observations on pulsar glitches up to date. 相似文献
8.
We study the distribution and transport of angular momentum in a self-gravitating accretion disk formed during the collapse of a rotating gas cloud. Using the surface density for the low-viscosity models and minimum-mass models presented by Cassen and Summers, Poisson's equation is solved explicitly to determine the effects of self-gravitation of the protostellar disk. Analytic expressions for the angular momentum of the central star and other relevant quantities of interest during the formation stage are presented.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.On leave from the City College of the City University of New York, U.S.A. 相似文献
9.
Impact of climate change on water resources in southern Taiwan 总被引：17，自引：0，他引：17
This study investigates the impact of climate change on water resources in southern Taiwan. The upstream catchment of Shin-Fa Bridge station in the Kao-Pen Creek basin was the study area chosen herein. The historical trends of meteorological variables, such as mean daily temperature, mean daily precipitation on wet days, monthly wet days, and the transition probabilities of daily precipitation occurrence in each month, at the Kao-Hsiung meteorological station, near the catchments were detected using a non-parametric statistical test. The trends of these meteorological variables were then employed to generate runoff in future climatic conditions using a continuous rainfall–runoff model. The analytical results indicate that the transition probabilities of daily precipitation occurrence significantly influence precipitation generation, and generated runoff for future climatic conditions in southern Taiwan was found to rise during the wet season and decline during the dry season. 相似文献
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