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RT Leonis Minoris:an Unstable W Ursae Majoris System with a Spotted Component

chinese Journal of astronomy and Astrophysics 2004年第6期4卷 553-562页

作者： Yu-Lan Yang and Qing-Yao LiuNational Astronomical Observatories, Yunnan Observatory, chinese academy of sciences,kunming 650011 United laboratory of optical astronomy, chinese academy of sciences National Astronomical Observatories Yunnan Observatory Chinese Academy of Sciences Kunming 650011 []United Laboratory of Optical Astronomy Chinese Academy of Sciences

Complete BV light curves of the W UMa type binary RT LMi are presented. From the observations, four times of minimum light were determined. Based on the new times of minimum light and those collected from the literature, changes in the orbital period of the system were found and analyzed with Kalimeris et al.'s method. The result shows that the orbital period possibly oscillates with a cycle of about 64 years and an amplitude of 1.2 × 10-6 days. The present CCD photometric observations reveal that the light curves are obviously asymmetrical, and show a positive O'Connell effect, while the light curves obtained in 1982 exhibit a negative O'Connell effect. The present light curves were analyzed by means of the latest version of the Wilson-Devinney code, which was also used to correct the photometric effects, including the distortion on the radial-velocity curves obtained by Rucinski et al. The following absolute dimensions have been derived: MI -1.28 ±0.08 M⊙, M2 = 0.48 ±0.06 M⊙, R1 = 1.28 ±0.06 R⊙, R2 = 0.83 ±0.05 R⊙, L1 = 1.88±0.12 L⊙, L2 = 0.77±0.08 L⊙, and A = 2.64±0.02 R⊙. The asymmetry of the light curves can be explained by a model with a cool spot on the secondary component. The orbital period modulation can be reproduced by a magnetic activity cycle model of the secondary component with ΔJ = 5.6 × 1046 g cm2 s-1, ΔΩ/Ω = 8.8 × 10-4, and B = 5.1 × 103 G.

关键词： star: contact binary - star: individuals: RT LMi - star: magnetic activity

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Stochastic Particle Acceleration in Blazar Jets

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chinese Journal of astronomy and Astrophysics 2002年第1期2卷 1-7页

作者： Jian-Cheng Wang Yunnan Observatory Chinse academy of sciences, kunming 650011 National Astronomical Observatories, chinese academy of sciences, Beijing 100012 United laboratory of optical astronomy chinese academy of sciences Extragalactic astronomy Recei Yunnan Observatory Chinese Academy of Sciences Kunming 650011 []National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 []United Laboratory of Optical Astronomy Chinese Academy of Sciences

The bulk kinetic energy of jets can be dissipated via generating tur- bulen plasma waves. We examine stochastic particle acceleration in blazar jets to explain the emissions of all blazars. We show that acceleration of electrons by plasma turbulence wavs with a spectrum W(k) ~ k^(-4/3) produces a nonthermal population of relativistic electrons whose peak frequency of synchrotron emission can fit the observational trends in the spectral energy distribution of all blazars. The plasma nonlinear processes responsible for the formation of turbulent spectrum are investigated. Increases in the ioteraction time of turbulent waves can produce a fiatter spectrum leading to efficient particle acceleration.

关键词： acceleration of paxticles - blazars: theory - plasma: turbulence - radiation mechanism: nonthermal

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Recent study of emission line star 3G71

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chinese Science Bulletin 1998年第6期43卷 470-473页

作者： HANG Hengrong 1,2 and XIA Jianping+1 1. Purple Mountain Observatory, chinese academy of sciences, Nanjing 210008, china 2. joint laboratory for optical astronomy, chinese academy of sciences, Nanjing 210008, china Purple Mountain Observatory Chinese Academy of Sciences Nanjing China joint laboratory for optical astronomy Chinese Academy of Sciences Nanjing China

New spectral observations of 3G71 are presented. The main features of optical spectra which exhibit a lot of forbidden lines and unusual strong H-Balmer emission lines are discussed. Our data, together with its large IRAS infrared color excess and other characteristics, show evidence that the star may be a Herbig Ae/Be star rather than the optical counterpart of Be/X-ray source of 1H2214+589.

关键词： Be/X-ray binary emission line IRAS identification Herbig Ae/Be star.

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A puzzle of the radio-quiet quasar PG 1407+265:Are optical and X-ray emissions produced from a relativistic jet?

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Science china(Physics,Mechanics & astronomy) 2011年第1期54卷 183-186页

作者： CHEN Liang 1,2,3 & BAI JinMing 1,2 1 National Astronomical Observatories/Yunnan Observatory,chinese academy of sciences,kunming 650011,china 2 Key laboratory for the Structure and Evolution of Celestial Objects,chinese academy of sciences,kunming 650011,china 3 Graduate University of chinese academy of sciences,Beijing 100049,china 1. National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China2. Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China

PG 1407+265 is a radio quiet quasar that has a relativistic *** this report,we show some peculiar properties of its optical and X-ray emissions,which indicate possible non-thermal origins produced from the *** use a simple synchrotron + synchrotron self Compton (SSC) model to fit the emissions with different ratios of energy densities between the magnetic field and electrons (η≡U B/U e),which predicts a different γ-ray *** First LAT AGN Catalog (1LAC) did not include PG 1407+265,which indicates an upper limit of γ-ray *** upper limit constrains the ratio to be unreasonably large (η≥10 4-5).This inversely indicates that the optical and X-ray emissions may not be produced from the beaming *** discuss the physical implications of these results.

关键词： active galactic nuclei jet non-thermal emission PG 1407+265

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Accurate determination of the plate model based on CCD images with different orientations

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chinese Science Bulletin 2010年第9期55卷 791-796页

作者： PENG QingYu1,2,3,4 & FAN LiangYan1,2,3,4 1 joint laboratory for Astrometry, Dynamics and Space Science, Jinan University, Guangzhou 510632, china 2 Department of Computer Science, Jinan University, Guangzhou 510632, china 3 Key laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Educational Institutes, Jinan University, Guangzhou 510632, china 4.joint laboratory for optical astronomy, chinese academy of sciences, kunming 650011, china joint laboratory for Astrometry Dynamics and Space Science Jinan University Guangzhou China Department of Computer Science Jinan University Guangzhou China Key laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Educational Institutes Jinan University Guangzhou China joint laboratory for optical astronomy Chinese Academy of Sciences Kunming China

The images of the open cluster NGC2168 are taken using the newly-fitted 2k×2k CCD attached to the 1-m telescope at the Yun-nan Observatory with two different orientations. After the catalogue position of a star from UCAC2 is compared with its corresponding measured position, a surprising result shows that a small field of view (about 7′×7′) exhibits an obvious distortion. Spe-cifically, the polynomial between the standard coordinate (ξ,η) and its corresponding measured one (x,y) for a star in each field of view has significant terms as high as 4th order. Accordingly, the positional measurement accuracy of a bright UCAC2 star can be derived as well as ~7 mas in each direction (60 s of exposure time and near the zenith). This new finding would be important for a CCD image to deliver a highly accurate position in its whole field of view.

关键词： CCD imaging field distortion positional measurement image analysis

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2MASS photometry and age estimation of the globular clusters in the outer halo of M31

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Research in astronomy and Astrophysics 2012年第2期12卷 115-126页

作者： Jun Ma 1,21 National Astronomical Observatories,chinese academy of sciences,Beijing 100012,china 2 Key laboratory of optical astronomy,National Astronomical Observatories,chinese academy of sciences,Beijing 100012,china National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Key laboratory of optical astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

We present the first photometric results in J, H and Ks from 2MASS （Two Micron All Sky Survey） imaging of 10 classical globular clusters （GCs） in the far outer regions of M31. Combined with the V and I photometric data from previous literature, we constructed a color-color diagram between J - Ks and V - Ⅰ. By comparing the integrated photometric measurements with evolutionary models, we estimate the ages of these clusters. The results showed that all of these clusters are older than 3 × 109 yr, and among them four are older than 10 Gyr and the other six have intermediate ages between 3 - 8 Gyr. The masses for these outer-halo GCs are from 7.0 × 104 M to 1.02 × 10^6 M. We argued that GC2 and GC3, whose ages, metallicities and distance moduli are almost the same, were accreted from the same satellite galaxy, if they did not form in situ. The statistical results show that the ages and metallicities of these 10 M31 outer-halo GCs do not vary with projected radial position, and a relationship between age and metallicity does not exist.

关键词： galaxies: halos - galaxies: individual (M31) - star clusters: general

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SOME PHENOMENA NEAR THE NUCLEUS OF THE COMET HALE-BOPP

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中国科学院上海天文台年刊 2000年 92-100页

作者： Wu Guangjie Chen Peisheng (Yunnan Observatory and United laboratory of optical astronomy, the chinese academy of sciences, kunming 650011, china)

An observational result from March 12 to April 15 for comet Hale-Bopp is given in this paper. During this period a fan-shaped erupted region with angular extent of about 100 degrees near the nucleus was seen continually. In addition, a shell structure with at most 5 layers often appeared. It is found that these layers were equal-spaced with a distance of about 2×10 4 km and were moving outward with a speed of about 35 m/s. It is suggested that this phenomenon was possibly a kind of wave created by charged attogram dust grains erupted from the nucleus, which collided with either the solar wind or material of the coma. The propagation period of the wave was about 6 days but the spin of the Comet Hale-Bopp could be very slow and the period was about 3 yr. This spin movement had the opposite direction as its orbital motion.

关键词： Comets - Cometary nucleus - Cometary dust - Periods - Solar wind

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Narrow line Seyfert 1 galaxies: where are the broad line regions?

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Science china(Physics,Mechanics & astronomy) 2010年第12期53卷 2307-2311,2339-2343页

作者： MAO WeiMing 1,2,3 , HU Chen 2 , WANG JianMin 2 , BIAN WeiHao 4 , ZHANG Shu 2 & ZHAO Gang 1 1 Key laboratory of optical astronomy, National Astronomical Observatories, chinese academy of sciences, Beijing 100012, china 2 Key laboratory for Particle Astrophysics, Institute of High Energy Physics, chinese academy of sciences, Beijing 100049, china 3 Graduate University of the chinese academy of sciences, Beijing 100049, china 4 Department of Physics, Nanjing Normal University, Nanjing 210011, china 1. Key laboratory of optical astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China2. Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China3. Graduate University of the Chinese Academy of Sciences Beijing 100049 China4. Department of Physics Nanjing Normal University Nanjing 210011 China

A sample consisting of 211 narrow line Seyfert 1 galaxies (NLS1s) with high quality spectra from the Sloan Digital Sky Survey (SDSS) is selected to explore where broad line regions are in these objects. We find that the Hβ profile can be fitted well by three (narrow, intermediate and broad) Gaussian components, and the FWHM ratios of the broad to the intermediate components hold a constant of 3.0 roughly for the entire sample. If the broad components originate from the region scaled by the well-determined Hβ reverberation mapping relation, we find that the intermediate components originate from the inner edge of the torus, which is scaled by dust K-band reverberation. We find that the IC and the BC are strongly linked dynamically, but the relation of their covering factors is much more relaxed, implying that both regions are clumpy.

关键词： black hole physics galaxies: evolution quasars: general

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Observations of the 1988 Leonids at Gaomeigu

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天文研究与技术 1999年第S1期 471-475页

作者： Wu Guangjie, Zhang Zhousheng (Yunnan Observatory and United laboratory of optical astronomy, The chinese academy of sciences, kunming 650011, china)

The 1998 Leonid meteor shower was observed at the Gaomeigu station of Yunnan Observatory during 5 successive days in November. The visual records indicates that the number of the meteor increased suddenly in the early morning of November 17th in Beijing time, with a maximum of ZHR about 340. But it deceased slowly in the following two days. During the maximum it had a high proportion of about 10 percent of very bright

关键词： Observations of the 1988 Leonids at Gaomeigu

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About the O'Connell Effect of a Close Binary

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天文研究与技术 1999年第S1期 378-382页

作者： Liu Qingyao, Yang Yulan (Yunnan Observatory, The chinese academy of sciences, kunming 650011, china) (United laboratory of optical astronomy, The chinese academy of sciences, kunming 650011, china) (National Astronomical Observatories, The chinese Acad

Based on the hypothesis that the circumstellar matter of a binary system is captured by its components a theoretical model for explaining the O’Connell effect of the colse binary is given in this present article.

关键词： About the O’Connell Effect of a Close Binary In

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