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Planet Host Stars: Mass, Age and Kinematics

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Chinese Journal of Astronomy and Astrophysics 2002年第2期2卷 151-160页

作者： Yu-Qin Chen and gang Zhao National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

We determine the mass, age and kinematics of 51 extra-solar planet host stars. The results are then used to search for signs of connection of the data with metallicity and to investigate the population nature. We find that the increase in mean metallicity with stellar mass is similar to that in normal field stars, so it seems unsuitable to use this relation as a constraint on the theory of planet formation. The age and kinematic distributions seem to favour the metallicity of extra-solar planet host stars being initial. Although the kinematic data of these stars indicate their origin from two populations - the thin and the thick disks, kinematics may not help in the maintenance of the planet around the host. Stars with planets, brown dwarfs or stellar companions are sorted into three groups and re-investigated separately for their formation mechanism. The main results indicate that stars with M2 0.1 and a wide period range, but there are no other differences. Thus, there does not seem to be any physically distinguishable characteristics among the three star groups.

关键词： stars: masses ages ─ stars: kinematics -planetary system

Star Formation and Chemical Enrichment for globular Clusters

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Chinese Physics Letters 2001年第11期18卷 1536-1538页

作者： LIN Qhig SHU Cheng-gang CHANg Rui-Xiang ZHAO Jun-Liang Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030

A model considering gas outflows due to supernova explosions is developed for the star formation and chemical enrichment for the globular clusters (gCs) in the Milky Way galaxy. Through Monte Carlo simulations, the observed global properties of gCs can be well reproduced, including the metallicity distribution, no-correlation between cluster masses and galactocentric distances, etc. The predicted mass function of the parent clouds for the observed gCs at present day can be well described as a power law with the index of-1.8, which is consistent with the current observations for the molecular clouds.

关键词： galaxy observed clouds

Abundance gradients in the galactic disk

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Science China(Physics,Mechanics & Astronomy) 2003年第1期46卷 52-61页

作者：崔辰州陈玉琴赵刚赵永恒 National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China

The relationship between abundances and orbital parameters for 235 F- and g-type intermediate- and low- mass stars in the galaxy is analyzed. We foundthat there are abundance gradients in the thin disk in both radial and verticaldirections (-0.116 dex kpc-1 and -0.309 dex kpc-1 respectively). The gradients appear to be flatter as the galaxy evolves. No gradient is found in the thick disk based on 18 thick disk stars. These results indicate that the ELS model is mainly suitable for the evolution of the thin disk, while the SZ model is more suitable for the evolution of the thick disk. Additionally, these results indicate that in-fall and out-flow processes play important roles in the chemical evolution of the galaxy.

关键词： late-type stars, abundances, galactic disk, evolution.

Equivalent Widths of 15 Extrasolar-Planet Host Stars

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Chinese Journal of Astronomy and Astrophysics 2002年第4期2卷 377-390页

作者： gang Zhao, Yu-Qin Chen and Hong-Mei QiuNational Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 National Astronomical Observatories CAS NAOC Beijing 100012 China

We present the equivalent widths of 15 extrasolar-planet host stars. These data were based on the high-resolution, high signal-to-noise ratio spectra obtained with the 2.16m telescope at Xinglong station. The error in the Xinglong equivalent width is estimated by a comparison of these data with those given in previous studies of common stars.

关键词： stars: planetary systems - stars: late-type

The Coudé Echelle Spectrograph for the Xinglong 2.16m Telescope

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Chinese Journal of Astronomy and Astrophysics 2001年第6期1卷 555-562页

作者： gang Zhao and Hong-Bin Li National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

A brief description of the NAO coude echelle spectrograph mounted on the 2.16 m telescope at Xinglong station is given. This echelle spectrograph is located at the coudé focus with a prism cross disperser. The echelle image covers the spectral region from 330 to 1100 nm displayed in 80 spectral orders in one exposure through two light beams. With a slit height of 2mm, spectral orders are separated by 15 to 23 pixels in blue region and by 7 to 19 pixels in red region. Alternatively, two additional resolution modes corresponding to different focal length cameras with resolving power R 16000, 170 000 in the blue beam and R = 13000, 170 000 in the red beam could be provided by this spectrograph. The bias, dark, wavelength calibration, flat field and science exposure are described in details. The limiting magnitude for 1 hour exposure with an S/N ratio of 100 scales to V = 9.5 in the red path and to V = 7.2 in the blue path.

关键词： instrumentation: spectrographs methods: observational - techniques: spectroscopic

Nucleosynthesis yields from different mass stars

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Progress in Natural Science:Materials International 2002年第1期 12-18页

作者： LIANg Yanchun and ZHAO gang(National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China) National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

Stellar nucleosynthesis yield is a vital factor of galactic chemical evolution model. With different yields, various evolutionary behavior of elements can be predicted, hence different scenarios of galactic chemical evolution can be shown. Investigators calculated different yields adopting different parameters of stellar evolution and nucleosynthesis. The corresponding parameters and the resulting yields of elements are compared for low-, intermediate-mass stars and massive stars, so that these analyses can provide valuable information and guidance to stellar nucleosynthesis and galactic chemical evolution studies.

关键词： nucleosynthesis yields galactic chemical evolution different mass stars.

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虚拟天文台的技术进展

天文学进展 2002年第4期20卷 302-311页

作者：崔辰州赵永恒赵刚张彦霞中国科学院国家天文台北京100012

虚拟天文台是在望远镜和探测器的研制技术、计算机网络技术取得突破性进展的条件下产生的,与最新的信息技术紧密结合成为其发展最鲜明的特点。用可扩展标记语言(简称XML)技术封装天文数据,把虚拟天文台建立在网格的体系结构之上是当今... 详细信息

虚拟天文台是在望远镜和探测器的研制技术、计算机网络技术取得突破性进展的条件下产生的,与最新的信息技术紧密结合成为其发展最鲜明的特点。用可扩展标记语言(简称XML)技术封装天文数据,把虚拟天文台建立在网格的体系结构之上是当今虚拟天文台技术发展的主流。按照目前虚拟天文台最具代表性的层次式体系结构分层介绍各个层次的相关技术,同时提出充分利用现有资源优势实施中国虚拟天文台计划的设想。

关键词：技术虚拟天文台标准仪器网络方法数据处理

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类铍氧离子X射线及EUV光谱理论模拟

天文学报 2005年第2期46卷 151-157页

作者：梁雅琼仲佳勇中国科学院物理研究所北京100080 中国科学院国家天文台北京100012

根据非局域热动平衡状态下谱线形成理论,利用相对论多组态原子程序软件包FAC模拟了类铍氧离子的X射线及EUV光谱.分析了间接过程对类铍氧离子X射线及EUV光谱形成的影响.在典型天体等离子体密度(ne=1010/立方厘米)情况下,采用了3种模型,... 详细信息

根据非局域热动平衡状态下谱线形成理论,利用相对论多组态原子程序软件包FAC模拟了类铍氧离子的X射线及EUV光谱.分析了间接过程对类铍氧离子X射线及EUV光谱形成的影响.在典型天体等离子体密度(ne=1010/立方厘米)情况下,采用了3种模型,在不同温度下模拟X射线及EUV光谱形成过程,分析比较了间接过程对谱线形成的贡献,并给出了它们的速率系数,得出了在谱线形成过程中,间接过程具有非常重要的作用.

关键词：类铍氧离子 X射线 EUV光谱速率系数碰撞辐射模型复合系数