共查询到20条相似文献，搜索用时 874 毫秒
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赵定烽 《中国天文和天体物理学报》1996,(3)
对观测到的受星风或膨胀气壳包围的双星系统的PCyg谱线理论分析可精确测定其星风物质损失率．我们在计算这类星的理论谱线时，考虑了氢氦混合气体的多能级跃迁、轨道运动引起的密度非径向分布等因素，对轨道形状做了简化，所得结果是令人满意的． 相似文献
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受星风或膨胀气壳包围的双星物质损失率测定 总被引：3，自引：0，他引：3
对观测到的受星风或膨胀气壳包围的双星系统的ＰＣｙｇ谱线理论分析可精确测定其星风物质损失率，我们在计算这类星的理论谱线时，考虑了氢氦混合气体的多能级跃迁，轨道运动引起的密度非径向分布等因素，对轨道形状做了简化，所得结果是令人满意的。 相似文献
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太阳磁场的诊断是太阳物理研究中非常重要的一部分.斯托克斯参量I、Q、U和V可以用来完整描述偏振光的信息,对观测得到的斯托克斯光谱进行反演可以诊断太阳磁场的信息.近几十年来,塞曼效应成为磁场诊断的主要手段,利用塞曼效应使谱线产生的分裂可以诊断强度达到几百高斯的强磁场,但是在太阳宁静区中存在大量强度小于100 Gs的弱磁场,对于弱磁场可以利用汉勒效应来诊断,应用汉勒效应诊断弱磁场一直是磁场诊断的主要内容之一,需要对偏振的产生机制有更完整的理解.文章的主要内容是研究在采用不同原子模型的假设下,由散射产生的谱线轮廓的区别,以及在存在磁场时,不同原子模型谱线的汉勒效应的区别.以中性镁为研究对象,选取了7能级、4能级和2能级原子模型,分别研究了这几个原子模型对散射偏振和汉勒效应的影响.发现2能级原子模型和多能级(7能级和4能级)原子模型产生的谱线的偏振度有很大的区别,并且在2能级原子模型假设下b_4线不存在下能级的汉勒效应,但是在多能级的原子模型下b_4线仍存在下能级的汉勒效应.对比7能级原子模型和4能级原子模型,谱线的偏振度只有很小的变化,汉勒效应的表现也基本相同.主要结论如下:在利用中性镁b 3线的线偏振轮廓Q/I反演磁场时,至少需要采用4个能级的原子模型.这主要依赖于谱线形成区域的原子的能级分布,原子能级占有数多的能级在研究中是必须考虑的. 相似文献
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关于银河系发射单色电波辐射的可能性首先是由方·特·胡尔斯特指出的。这种辐射可由原子或分子的极相近而分立的能级之间的电子跃迁产生。因为星际空间的条件影响,最大多数的原子和分子都处于基态,所以就需要考虑在同一基态中的各能级之间的跃迁。这篇文章就是研究星际原子和分子的一切可能的上述跃迁。由原子的精细结构的分量间的跃迁所引起的辐射以及星际分子—氢化物的 相似文献
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使用紫金山天文台青海观测站13．7米毫米波射电望远镜,于1996年12月10日至1997年1月2日和1997年3月25日至1997年4月4日对海尔－波普彗星的CO分子J＝1—0转动跃迁谱线（频率为115．27120GHz）进行了观测．观测谱线表明,CO分子相对于地心的速度比彗星整体相对于地心的速度要小些,即有蓝移现象．这反映了CO分子是由该彗星迎着太阳的面以一定的速度产生出来的．从观测谱线中还初步估算了该彗星CO分子的产生速率． 相似文献
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一九八五年十一月十三日和十六日在国际哈雷彗星射电联测时段内,由加州大学贝克利分校I.D.Pater、芝加哥大学P.Palmer、伊利诺斯州立大学L.E.Snyder组成的观测小组,用设在新墨西哥州的美国国家射电天文台(NRAO)甚大阵(VLA)观测哈雷彗星的羟基(OH)谱线发射,得到了羟基最低能态(2II_3/2,J_5/3)F=2→2跃迁谱线(频率为 相似文献
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V. Banfi 《Celestial Mechanics and Dynamical Astronomy》1987,40(1):67-76
The containment property Goudas' surfaces has been studied in this paper. Physical implications of this property a consequently discussed. A general relationship is obtained, which connects the sizes of those surfaces, the magnetic moments of two stars and their mean motion. 相似文献
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Michel Rapaport 《Celestial Mechanics and Dynamical Astronomy》1976,13(2):217-227
We use classical definitions and results of differential geometry in studying properties of transformations depending on a small parameter, acting on differential systems. Hori's and Deprit's algorithms can be defined for these systems. A lemma is given to show these algorithms are equivalent. The so-called property of covariance is merely established. The canonical systems are then considered as associated with Hamiltonian vectorfields on symplectic manifolds. The property that the infinitesimal generator of a canonical transformation is an Hamiltonian vectorfield permits to establish separately the generality of Hori's and Deprit's algorithms. We suggest that the Hamiltonian vectorfield property can be extended to the generators of transformations depending on several parameters. 相似文献
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P. Moore 《Celestial Mechanics and Dynamical Astronomy》1978,17(3):281-297
Lambert and Watson (1976) examine the family of symmetric linear multistep methods for the special second-order initial value problem, and connect the property of symmetry with a property of periodicity. The problems of celestial mechanics may be formulated as second-order initial value problems, but these frequently incorporate the first derivative explicity. It is common for such equations to be reduced to a system of first-order equations. Thus motivated, we utilize ideas from the aforementioned paper to determine the family of linear multistep methods for first-order initial value problems that possess an analogous property of periodicity. This family of orbitally stable methods is illustrated by examining the regularized equations of motion of an artificial earth satellite in an oblate atmosphere. 相似文献
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光变是活动星系统的共同特征,光变规律的研究已成为人类探索活动星系核物理的有力手段,综述了类星体样本光变的研究现状,对样本的光变比例,光变类星体的平均光变幅,光变时间尺度,光变幅与类星体物理参量的相关情况,类星体样本光变和其它活动星系核样本的关系进行了详细评述,并评述了样本光变的星暴模型,微透镜模型,吸积盘模型三种理论模型。 相似文献
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本文给出了各种红外双色图中的黑体线方程并进行了具体的计算。应用本文的计算结果，可以方便地确定双色图中的黑体线，而不必再进行一系列繁杂的计算。此外，文中还详细地讨论了红外双色图中黑体线的数学性质和物理意义。 相似文献
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路声东 《中国天文和天体物理学报》1992,(3)
本文是对于摄谱仪准直畸像光学系统研究的继续和深入,认真分析了Wynne的卡焦摄谱仪畸像系统的设计思想,认为可以避免像他那样将畸像系统设置在卡焦前会聚光束中(致使畸像系统变得复杂),而设置在摄谱仪准直光路中更为合理.作者与蒋世仰教授曾首次提出了准直畸像系统的概念,现在对于其中所提的反射系统的工作有所推进,寻求得到了一种结构简单、易于制作的系统.它仅由两个圆柱面构成,是一种柱面的类Mersenne系统.文中说明了在一定的条件下可以由圆柱面代替柱面Mersenne系统的抛物柱面(该系统在中已被提出过)、这种类Mersenne系统既可置于折轴摄谱仪中,亦可置于卡焦摄谱仪中,且能在大直径准直光束中起较剧烈的畸像作用,当然也具有反射系统所固有的优点——接收更宽的波段,特别在非可见光区优于透射系统.给出的算例说明该系统的准直误差极小. 相似文献
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In this paper we have made an attempt to define hierarchy of distribution functions for the simultaneous velocity and magnetic fields. Various properties of the constructed functions such as reduction property, separation property, coincidence properties have been discussed, and equations for the evaluation of one- and two-point bivariate distribution functions have been derived. 相似文献
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Ju. V. Glagolevsky 《Astrophysics》2005,48(2):194-207
Some difficulties in explaining the slow rotation of CP stars are discussed. The most likely hypotheses are (1) a loss of angular momentum involving a magnetic field during “pre-main sequence” evolution and (2) the slow rotation existed from the very start of the creation of these stars. The braking hypothesis is supported by only one property of CP stars— the lower the mass of the star is, the greater the difference between its average rotation velocity vsini and that of normal stars. On the other hand, there is another property— the lower the rotation speeds of CP stars are, the greater their fraction among normal stars. The latter property supports the hypothesis that the lower the initial rotation speed of a star is when it is created, the greater the probability will become chemically peculiar. This property is inherent in chemically peculiar stars both with and without a magnetic field. It is proposed that the cause of the slow rotation of CP stars must be sought in the very earliest phases of their formation, as should the cause of the separation into chemically peculiar magnetic, chemically peculiar nonmagnetic, and normal stars.__________Translated from Astrofizika, Vol. 48, No. 2, pp. 229–245 (May 2005). 相似文献
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Motion of a charged particle around a black hole immersed in magnetic field is calculated. It is shown that this motion has a chaotic property depending on initial parameters. 相似文献
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Marcelo Samuel Berman 《Astrophysics and Space Science》2007,312(3-4):275-278
We discuss astronomical and astrophysical evidence, which we relate to the principle of zero-total energy of the Universe,
that imply several relations among the mass M, the radius R and the angular momentum L of a “large” sphere representing a Machian Universe. By calculating the angular speed, we find a peculiar centripetal acceleration
for the Universe. This is an ubiquituous property that relates one observer to any observable. It turns out that this is exactly
the anomalous acceleration observed on the Pioneers spaceships. We have thus shown that this anomaly is to be considered a
property of the Machian Universe. We discuss several possible arguments against our proposal. 相似文献