排序方式: 共有134条查询结果,搜索用时 453 毫秒
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WANGXiao-Feng ZHANGTian-Meng ZHOUXu LIZong-Wei 《中国物理快报》2004,21(7):1398-1401
We study the circumstellar interaction around SN 1993J by its intermediate-band light curves obtained by the 60/90 cm Schmidt telescope at Xinglong station. The optical emission showed a slow decay of 0.054-0.02 mag/100d in the period from 1995 to 2003, invoking a main energy contribution from SN-circumstellar interaction at late times. The relatively flat power law SN density model fits better with the observations. In particular, the lineratio of [O Ⅲ])λλ4959, 5007 and Na I D relative to Ha are well reproduced by the model. Moreover, the Hα light curve displayed obvious bump structures at some epochs, which is probably attributed to the density fluctuations in the ambient material that surrounds the reverse shockwave. 相似文献
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We study the fluxes and the death lines of γ-ray emission of the pulsars with outer gaps.In a self-sustained outer gap,we derive that the fractional size of the outer gap is a function of period,period derivative,radial distance and magnetic inclination angle for a pulsar.Our results indicate that (i) averaged typical γ-ray energy and γ-ray flux of a pulsar with an outer gap increase with the magnetic inclination angle;we estimate the averaged γ-ray fluxes for observed canonical pulsars with outer gaps and compare them with the sensitivities of AGILE and GLAST,and (ii) if the fractional size of the outer gap at the inner boundary of the outer gap is not greater than unity,then an outer gap exists;such a condition gives the death lines of the pulsars with outer gaps. 相似文献
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星际26Al核合成研究面临的困难—核天体物理学的重大疑难问题 总被引:6,自引:0,他引:6
介绍了有关星际26Al(衰变伴随1.809MeVγ射线)的空间观测结果:讨论了与26Al及其有关放射性核素(22Na)的核反应链及其最近核物理实验进展,并由此分析了目前关于星际26Al起源的各种天体模型面临的困难。最后,作者提出一产生星际26Al的新的可能的途径与Ia型超新星模型的设想。 相似文献
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It is still a matter of debate to understand the equation of state of cold matter with supra-nuclear density in compact stars because of unknown non-perturbative strong interaction between quarks. Nevertheless, it is speculated from an astrophysical view point that quark clusters could form in cold quark matter due to strong coupling at realistic baryon densities. Although it is hard to calculate this conjectured matter from first principles, one can expect that the inter-cluster interaction will share some general features with the nucleon-nucleon interaction successfully depicted by various models. We adopt a two-Gaussian component soft-core potential with these general features and show that quark clusters can form stable simple cubic crystal structure if we assume that the wave function of quark clusters have a Gaussian form. With this parametrization, the Tolman-Oppenheimer-Volkoff equation is solved with reasonably constrained parameter space to give mass-radius relations of crystalline solid quark stars. With baryon number densities truncated at 2n0 at surface and the range of the interaction fixed at 2 fm we can reproduce similar mass-radius relations to that obtained with bag model equations of state. The maximum mass ranges from 0.5M⊙ to 3M⊙. The recently measured high pulsar mass ( 2M⊙) is then used to constrain the parameters of this simple interaction potential. 相似文献
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文章介绍了2002年诺贝尔物理学奖获得者贾科尼对X射线天文学的开创性贡献,特别介绍了贾科尼等在开拓空间观测和发展x射线成像技术这两个方面的工作.文章通过x射线天文学的诞生、X射线天文卫星的发展介绍了X射线的空间观测对天体物理学的影响,对宇宙暗物质、双星中的吸积过程和X射线喷流现象等进行了简单介绍,并对高能天体物理学的发展给出了概略的描述. 相似文献
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In this paper, the stellar velocity dispersions in the host galaxies are used to estimate the central black hole masses for a sample of elliptical galaxies. We find that the central black hole masses are in the range of 10^{(5.5-9.5)}M_⊙. Based on the estimated masses in this paper and those by Woo & Urry (2002) and the measured host galaxy absolute magnitude, a relation, log (M_{BH}/M_⊙) = -(0.25±4.3×10^{-3})M_R + (2.98±0.208) is found for central black hole mass and the host galaxy magnitude. Some discussions are presented. 相似文献