后发团盘星系自转轴方向的分布

本文对后发团中心２．６３°×２．６３°范围内１３８个盘星系（９４个Ｓ０星系，４４个Ｓ和Ｉｒ星系）的自转轴方向的分布作了分析，结果表明，后发团中盘星系自转轴方向的分布是非均匀的．相对于假设的均匀分布，有较多的Ｓ０星系的自转轴平行于团平面，并且Ｓ０星系的自转轴在团平面上的投影倾向于沿着偏离团中心方向约４５°的方向；对于Ｓ和Ｉｒｒ星系，自转轴倾向于平行或垂直于团平面，自转轴在团平面上的投影则倾向于平行团中心方向．本文证实了后发团中盘星系自转轴方向分布的非均匀性及其与星系形态类型的相关，而且可能与星系光度也有关．样本越深，自转轴指向的分布似乎越不均匀．本文结果说明后发团存在一个优势平面（可能的团平面），在各种星系团及星系形成理论中，有支持“薄饼”（ｐａｎｃａｋｅ）模型的迹象．     

巨分子云聚合形成N体模拟中粒子数的效应

通过N体数值模拟以不同粒子数对星系中巨分子云的形成的影响进行了研究。结果表明：在聚合形成机制下，当对不同数目的分子云取相同的平均密度时，基本分子云的有效半径与其相应质量的立方根成正比，巨分子云的碎裂率与模拟基本分子云的数目无关。     

Comparisons of Infrared Colors and Emission-line Intensities between Two types of Seyfert 2 Galaxies

We study the relation between the infrared colors[ OⅢ] emission lines,gaseous absorbing column density(NH) ,and the detectability of the polarized (hidden)broad-line region(HBLR) in a large sample of 75 Seyfert 2 galaxies(Sy2s).From the indicators of star-formation activity,f60/f100 and LFIR/LB,we find some evidence that the Sy2s without HBLR show higher star-formation activities than those with HBLR,in agreement with previous prediction.Also,we confirm that the HBLR Sy2s tend to have a larger luminosity ratio of the core to the host galaxy,suggesting that the HBLR Sy2s display more powerful AGN activity.Howerver,the level of obscuration found in previous papers in nearly indistinguishable between the two types of Sy2s.The results support the statement that the non-HBLR Sy2s,with a weaker core component and a stronger star-formation activity component,are intrinsically different from the HBLR Sy2s,which are Sy1 systems with a hidden powerful AGN core and a low star-formation activity.The indications are that the non-HBLR Sy2s might be at an earlier evolutionary phase than the HBLR Sy2s.     

Near—Infrared Imaging Observations of the Orion A—W Star Forming Region

We carried out near-infrared imaging observations of the Ori A-W region using the Italian 1.5m TIRGO infrared telescope at Gornergrat. A group of infrared objects is visible on the K band image, including an IRAS source (IRS 1). From its IRAS flux density the IRAS luminosity is derived to be 45L⊙, which shows that IRS 1 is a low-mass protostar. By superimposing the position of the VLA H2O maser on the K image, we can identify the less evolved object IRS 1 as the excitation source of the H2O maser, within a projected distance of 470AU. This would be evidence that the maser effect is associated with the youngest phase of stellar evolution. The first probable HH object candidate in the Ori A-W region is discovered from the H2 S(1) 1-0 observation. Comparing the position of the H2O maser with the direction of the molecular hydrogen emission in the region, we suggest that the observed H2O maser could be tracing the circumstellar disk of IRS 1.     

OH megamaser的光度和它们的宿主星系的红外光度之间的相关关系

利用66个OH megamaser的光度和它们的宿主星系的红外光度之间的相关关系,得到log L(OH)=1.71log L(IR)-17.67,即L(OH)α[L(IR)]1。71.这个结果介于Baan所得到的L(OH)α[L(IR)]2和Kandalian所得到的L(OH)α[L(IR)]1.38的结果之间.由于统计时所取的样本数最多,因此结果更能反映实际情况.进一步,可把这66个OH megamaser分为两类;第一类为L(OH)<102L(?)的小光度OH megamaser,小光度OH megamaser包含了14个OH megamaser;第二类为L(OH)≥102L的大光度OH megamaser,大光度OH megamaser包含了52个OHmegamaser.研究结果表明,小光度OH megamaser的光度和它们的宿主星系的红外光度之间相关关系为L(OH)α[L(IR)]1.43,与Kandalia所得到的结果相接近.大光度OH megamaser的光度和它们的宿主星系的红外光度之间的相关关系为L(OH)α[L(IR)]2,与Baan所得到的结果相一致.     

活动星系核的统一模式

本文评述活动星系统的统一模式理论研究。这一研究的基础是活动星系核的相对论性射束效应和它周围各向异生气体的遮蔽效应，我们首选叙述几种统一模式，并阐述其发展。然后讨论检验统一模式的统计检验进展，特别是Ｒ参数的作用，本文还评述了多波段（特别是光学和红外）的统一模式统计检验问题。     

星系形成的超大型计算机模拟

扼要地就数值模拟在星系形成研究中的作用，数值模拟与解析模型之间的关系，数值模拟的局限性等几方面的问题作了综述，然后介绍了马普小组与日本东京大学最近的合作情况，包括合作得到的模拟样本，研究成晨和正在开展的工作。     

活动星系的非相对论性外流

活动星系核有两类常见外流，相对论性的射电喷流和非相对论性的物质外流，前者主要在射电强的适动星系核中，以非热辐射为特征，非相对论性外流主要通过紫外吸收线观测到，总结了类星体非对论性外流的一些性质及其X射线观测给出了的问题，指出现有的观测表明非相对论性外流引起的质量损失很重要。     

The Hybrid Nature of 0846＋51W1： a BL Lac Object with a Narrow Line Seyfert 1 Nucleus

We found a NLS1 nucleus in the extensively studied eruptive BL Lac object, 0846+51W1, out of a large sample of NLS1s compiled from the spectroscopic dataset of SDSS DR1. Its optical spectrum can be well decomposed into three components: a power law component from the relativistic jet, a stellar component from the host galaxy, and a component from a typical NLS1 nucleus. The emission line properties of 0846+51W1, FWHM