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Development of superconducting mixers for THz astronomy

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Science China(Information sciences) 2012年第1期55卷 120-126页

作者： SHI ShengCai1,2 1purple mountain observatory,chinese academy of sciences,nanjing 210008,China 2Key Laboratory of Radio Astronomy,chinese academy of sciences,nanjing 210008,China 1. purple mountain observatory Chinese Academy of Sciences Nanjing 210008 China2. Key Laboratory of Radio Astronomy Chinese Academy of Sciences Nanjing 210008 China

The terahertz(THz)regime,loosely defined as 0.1-10 THz,is the last frequency window to be fully explored in *** particular,it is a regime in which there are rich molecular rotation lines and atomic fine structure *** are very important tracers for studying the dynamics of astronomical objects such as stars and planetary *** those spectral lines usually makes use of coherent detectors(i.e.,heterodyne mixers).With sensitivity approaching the quantum limit,superconducting mixers have become the coherent detector of choice in THz *** this paper we mainly introduce the superconducting mixers developed at purple mountain observatory and those for international collaborative projects.

关键词： terahertz detection superconducting mixer quantum limit

Simulations for terrestrial planets formation

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Science China(Physics,Mechanics & Astronomy) 2009年第5期52卷 794-803页

作者： ZHANG Niu 1,2 &JI JiangHui 2,3 1Graduate University of chinese academy of sciences,Beijing 100049,China 2purple mountain observatory,chinese academy of sciences,nanjing 210008,China 3 National Astronomical Observatories,chinese academy of sciences,Beijing 100012,China Graduate University of chinese academy of sciences Beijing 100049 China purple mountain observatory Chinese Academy of Sciences Nanjing 210008 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

In this paper,the formation of terrestrial planets in the late stage of planetary formation is investigated using the two-planet *** that time,the protostar formed for about 3 Ma and the gas disk *** the model,the perturbations from Jupiter and Saturn are *** of the mass of outer planet,and the initial eccentricities and inclinations of embryos and planetesimals are also *** results show that,terrestrial planets are formed in 50 Ma,and the accretion rate is about 60%-80%.In each simulation,3-4 terrestrial planets are formed inside"Jupiter"with masses of 0.15 -3.6M⊕.In the 0.5-4 AU,when the eccentricities of planetesimals are excited,planetesimals are able to accrete material from wide radial *** plenty of water material of the terrestrial planet in the Habitable Zone may be transferred from the farther places by this *** could also happen a few times between two major planets only if the outer planet has a moderate mass and the small terrestrial planet could survive at some resonances over time scale of 10 8 *** one of our simulations,commensurability of the orbital periods of planets is very ***,a librating-circulating 3:2 configuration of mean motion resonance is found.

关键词： astrophysics exoplanet planetary formation n-body simulation

The approximate state transition matrix based on non-orthogonal decomposition and its application in orbit determination

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Science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 555-561页

作者： CHEN WuShen1,2, MA JingYuan2, ZHANG Jing2 & LU BenKui2 1 nanjing University of Technology, nanjing 210009, China 2 purple mountain observatory, chinese academy of sciences, nanjing 210008, China 1. nanjing University of Technology Nanjing 210009 China2. Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China

The Unit Vector Method (UVM) is an orbit determination method extensively applied. In this paper, the UVM and classical Differential Orbit Improvement (DOI) are compared, and a fusion method is given for the orbit determination with different kind data. Based on non-orthogonal decomposition of position and velocity vectors, an approximation scheme is constructed to calculate the state transition matrix. This method simplifies the calculation of the approximate state transition matrix, analyzes the convergence mechanism of the UVM, and makes clear the defect of weight strategy in UVM. Results of orbit the determination with simulating and real data show that this method has good numerical stability and rational weight distribution.

关键词： Unit Vector Method state transition matrix non-orthogonal decomposition

Drifting bands of solar radio spikes

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chinese Science Bulletin 2008年第4期53卷 638-640页

作者： XU FuYing1,2& WU HongAo1,2 1 purple mountain observatory,chinese academy of sciences,nanjing 210008,China 2 National Astronomical Observatories,chinese academy of sciences,Beijing 100012,China purple mountain observatory Chinese Academy of Sciences Nanjing China National Astronomical Observatories Chinese Academy of Sciences Beijing China

The solar flare(1N/C5.3) occurred in NOAA 8742 on October 27,1999,and the accompanied complex radio burst was observed by the spectrometer with both high temporal(5 ms) and frequency(10 MHz) resolutions at purple mountain observatory(PMO).It started at 04:27:42 UT,peaked at 04:28:42 UT and ended at 04:29:18 *** most significant feature of the event might be the sequential spikes in both time and frequency to form three slow drift bands over the frequency range of ～5 to ≥7.5 GHz with almost the same drift rate about 2.7 GHz/*** relative bandwidth for the individual spikes varied from 1.6% to 4.9%,typically 3.3%.Based on electron cyclotron maser action driven by loss-cone anisotropy,the rare phenomena of slow drift band consisting of spikes were interpreted by spike source moving back and forth along the magnetic ***,the estimations of the narrow bandwidths of spike given by electron cyclotron maser theory coincided well with the observations.

关键词：太阳耀斑微波爆裂太阳活动天文学

An alternative evolution scenario for OAO 1657-415 and IGR J18483-0311

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Science China(Physics,Mechanics & Astronomy) 2010年第S1期53卷 130-134页

作者： LIU QingZhong1,2,LI Hui1,3 & YAN JingZhi1,2 1 purple mountain observatory,chinese academy of sciences,nanjing 210008,China 2 Service d’Astrophysique,CEA Saclay and University Paris Diderot,91191 Gif-sur-Yvette,France 3 Graduate University of chinese academy of sciences,Beijing 100049,China 1. purple mountain observatory Chinese Academy of Sciences Nanjing 210008 China 2. Service d’Astrophysique CEA Saclay and University Paris Diderot 91191 Gif-sur-Yvette France 3. Graduate University of chinese academy of sciences Beijing 100049 China

The relation between the spin period and the orbital period in high-mass X-ray binaries is ***/X-ray binaries and SG/X-ray binaries occupy different areas in Corbet's *** two SG/X-ray binaries,IGR J18483-0311 and OAO 1657-415,however,appear to occupy a transition region between Be/X-ray binaries and wind-fed SG/X-ray *** can be understood by noting that the neutron stars in the two SG/X-ray binaries have not reached their equilibrium spin periods when the donors evolved off the main ***,we provide an alternative scenario to explain their location in Corbet's diagram:the SG/X-ray binaries are the descendants of Be/X-ray binaries,*** supergiants in these systems were formed from O-type emission line stars instead of normal main-sequence ***,we suggest that there are two types of SG/X-ray binaries:one is directly evolved from a normal OB-type main sequence and neutron star system without an X-ray history,and the other evolved from a Be/X-ray binary with an X-ray history.

关键词： high-mass X-ray binary pulsar Corbet’s diagram stellar evolution

THE SPLITTING OF COMET HALLEY

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中国科学院上海天文台年刊 2000年 245-248页

作者： Chen Daohan 1 Liu Linzhong 1 Alan Gilmore 2 (1. purple mountain observatory, chinese academy of sciences, nanjing 210008) (2. Mount John observatory, New Zealand)

In combination with the authors previous obsewation about the splitting of Comet Halley in March 1986, the events involving the sharp, straight feature in the antisolar direction observed in the head of Comet Halley in 1910 (such as those occurring on May 14, 25 and 31, and June 2) are rediscussed The analysis leads to the following scenario: When Comet Halley explodes and splits, a fragment jettisoned or thrown off from the nucleus will, after moving in the direction of its tail, develop into a mini-comet. Although not well developed or permanent, it has its own plasma tail and, sometimes, a dust tail. If Bobrovnikoff’s definition of a secondary nucleus is assumed, then the fragment should be considered as a real secondary nucleus. It seems that the current idea of a tailward jet suggested by Sekanina and Larson is a wrong explanation for the plasma tail of a mini-comet and hence the rotation period of 52-53h for Comet Halley is

关键词： Astron Wallis California Washington Curtis

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关于太阳底部贯穿对流区的延伸程度

天文学报 2001年第2期42卷 121-124页

作者：熊大闰邓李才中国科学院紫金山天文台中国科学院北京天文台

The extension of the solar lower overshooting zone is discussed. There is no any near discontinuity of the derivatives of sound speed at the bottom of the lower overshooting zone, as described by the phenomenological non local mixing length theory. On the contrary, the temperature gradient turns smoothly from nearly adiabatic stratification into radiative one. In the lower overshooting zone the temperature gradient is sub adiabatic, but it is super radiative! Namely  rad << ad . The extension of the super radiative region (defined by L r/L ⊙≥1.01) is around 0.63 H p (0.053 R ⊙ ).

关键词：恒星对流贯穿对流太阳恒星演化内部结构

OUTBURSTS OF COMET HALE-BOPP

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中国科学院上海天文台年刊 2000年 87-91页

作者： Yang Benyou 1 Zhang Chunsheng 1 Fan Yixin 1 Cai Hongfang 1 Sun Shousheng 2 Zhang Yan 2 Sun Linan 2 (1. purple mountain observatory, chinese academy of sciences, nanjing 210008) (2. Qingdao Station of purple mountain observatory, Qingdao 266

In this paper, we present the observations of Comet Hale-Bopp by means of photoelectric and photographic photometry during the period from September to November of 1996. It is shown that there appears to have been 3 outbursts around 24 Sept., 26 Oct. and 13 Nov.; and it is also possible that an event of outburst has taken place around 9 Oct.

关键词： Comet Hale-Bopp - outburst - photometry

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星系振动的动力学研究进展

天文学进展 1998年第3期16卷 242-249页

作者：傅燕宁孙义燧南京大学天文系南京210093 中国科学院紫金山天文台南京210008

概括地介绍了盘星系的运动学边缘弯曲现象、盘星系中心的HI发射线空洞和棒旋星系中核球的长轴和棒的长轴不互相平行也不互相垂直等星系振动的问接观测证据；综述了星系振动动力学的理论研究情况，主要介绍了利用非静态维里方程和N体数... 详细信息

概括地介绍了盘星系的运动学边缘弯曲现象、盘星系中心的HI发射线空洞和棒旋星系中核球的长轴和棒的长轴不互相平行也不互相垂直等星系振动的问接观测证据；综述了星系振动动力学的理论研究情况，主要介绍了利用非静态维里方程和N体数值模拟得到的有关结果；展望了该领域今后的发展趋势，指出了建立引力自治的星系振动模型的必要性。

关键词：星系动力学天体力学星系振动