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Thermal analysis of the baffle structure of the solar Space Telescope

Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1755-1764页

作者： LI Rong1,2.3 & WANG Sen1,3 1 national astronomical Observatories,{2. academy of sciences,beijing 100012.china 2.Graduate University of {2. academy of sciences,beijing 100049,china 3 key laboratory of solar activity,national astronomical Observatories of {2. academy of sciences,beijing 100012.china chinese academy of {2. National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***) Graduate University of chinese academy of {2. Beijing China (GRID:grid.458514.9) national astronomical Observatories of {2. academy of sciences Key Laboratory of Solar Activity Beijing China (GRID:grid.450302.0) (ISNI:***) chinese academy of {2. National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***) national astronomical Observatories of {2. academy of sciences Key Laboratory of Solar Activity Beijing China (GRID:grid.450302.0) (ISNI:***)

The SST(Space solar Telescope) is an astronomical telescope with a primary mirror of 1 m in *** observes the sun with a small view field to ensure that its high spatial resolution imaging has 0.1″-0.15″ and high SNR(signal to noise ratio).Surrounding the small view field is still the sun,which is an intense source of both heat and stray *** baffles(the main baffle,the aperture,and the outer baffle),which are used to eliminate the stray light,will change the thermal flux in the SST and will weaken the effect of the thermal control *** this study,the compatibility analysis of the thermal effect of baffle structures in SST is *** GCF(Geometry Composing Function) and BRDF(Bidirectional Reflectance Distribution Function),which are two inherent related parameters in the compatibility analysis,are *** objective and method of the compatibility analysis are *** the thermal analysis software,the temperature fields are calculated for different lengths of the main baffle,different radii of apertures,different lengths of the outer baffle with a 3' tilt angle and 16' tilt angle,and different tilt angles of the outer baffle with a 2.0 mm length.A series of configurations and sizes of the baffles are studied with the goals of both thermal control and elimination of stray *** design of the baffle structure of SST is achieved:the main baffle of length 4100 mm,the internal shield of radius 494 mm,the outer baffle of length 2.0 mm,and the outer baffle of tilt angle 3' are successfully *** paper presents the relationship between the thermal control design and stray light elimination plan in the *** aims of the optimal design of the baffle structure of SST are *** thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.

关键词： baffle the main baffle the outer baffle GCF BRDF

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What does the Sun tell and hint now?

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Research in Astronomy and Astrophysics 2009年第9期9卷 959-965页

作者： Ke-Jun Li1,2.1 national astronomical Observatories /Yunnan Observatory,{2. academy of sciences,Kunming 650011,china 2.key laboratory of solar activity,national astronomical Observatories,{2. academy of sciences,beijing 100012.china national astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences key laboratory of {2. activity National Astronomical Observatories Chinese Academy of Sciences

Some historical records, which have held since the beginning of modern solar activity cycles, are being broken by the present Sun： cycle 2. records the longest cycle length and fall time; latitudes of high-latitude sunspots belonging to a new cycle around the minimum time of the cycle are statistically the lowest at present, compared with those of other cycles; there are only one or no sunspots in a month appearing at high latitudes for 58 months, which is the first time that such a long duration has been observed. The solar dynamo is believed to be slowing down due to：（1） the minimum smoothed monthly mean sunspot number is the smallest since cycle 16 onwards, and even probably among all modern solar cycles; and （2. once the time interval between the first observations of two neighboring sunspot groups is larger than 14 d, it should be approximately regarded as an observation of no sunspots on the visible solar disk, called a spotless event. Spotless events occur with the highest frequency around the minimum time of cycle 2., and the longest spotless event also appears around the minimum time for observations of the Sun since cycle 16. Cycle 2. is expected to have the lowest level of sunspot activity from cycle 16 onwards and even probably for all of the modern solar cycles.

关键词： Sun: activity -- Sun: general -- sunspots

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2.ASS 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 1,2. national astronomical Observatories,{2. academy of sciences,beijing 100012.china 2.key laboratory of Optical Astronomy,national astronomical Observatories,{2. academy of sciences,beijing 100012.china national astronomical Observatories Chinese Academy of Sciences key laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences

We present the first photometric results in J, H and Ks from 2.ASS （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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A method to predict amplitude and date of maximum sunspot number

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chinese Science Bulletin 2000年第14期45卷 1287-1290页

作者： HAN Yanbenbeijing astronomical Observatory, {2. academy of sciences, national astronomical Observatories, {2. academy of sciences, beijing 100012, {12. beijing astronomical Observatory Chinese Academy of Sciences National Astronomical Observatories Chinese Academy of Sciences Beijing China

A method to predict the amplitude and date of the maximum sunspot number is introduced. The regression analysis of the relationship between the variation rate of monthly sunspot numbers in the initial stage of solar cycles and both of the maximum and the time-length of ascending period of the cycle showed that they are closely correlative. In general, the maximum will be larger and the ascending period will be shorter when the rate is larger. The rate of sunspot numbers in the initial 2.years of the 2.rd cycle is thus analyzed based on these grounds and the maximum of the cycle is predicted. For the smoothed monthly sunspot numbers, the maximum will be about 139.2.±18.8 and the time-length of ascending period will be about 3.31 ±0.42.years, that is to say, the maximum will appear around the spring of the year 2.00. For the mean monthly ones, the maximum will be near 170.1±2..9 and the time-length of ascending period will be about 3.42.±0.46 years, that is to say, the appearing date of the maximum

关键词： solar activity prediction sunspot number 2.rd solar cycle.

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Spectroscopic study of globular clusters in the halo of M31 with the Xinglong 2.16 m telescope

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Research in Astronomy and Astrophysics 2011年第11期11卷 1298-1310页

作者： Zhou Fan1,2.Ya-Fang Huang1,2.Jin-Zeng Li1,2.Xu Zhou1,2.Jun Ma1,2.Hong Wu1,2.Tian-Meng Zhang1,2.and Yong-Heng Zhao1,2.1 national astronomical Observatories,{2. academy of sciences,beijing 100012.china 2.key laboratory of Optical Astronomy,national astronomical Observatories,{2. academy of sciences,beijing 100012.china national astronomical Observatories Chinese Academy of Sciences key laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences

We present spectroscopic observations for 11 confirmed globular clusters(GCs) of M31 with the OMR spectrograph on the 2.16 m telescope at the Xinglong site of national astronomical Observatories,{2. academy of *** of our sample clusters are located in the halo of M31 and the most remote one is out to a projected radius of 78.75 kpc from the galactic *** all our sample clusters,we measured the Lick absorption-line indices and radial *** is noted that most GCs in our sample are distinct from the HI rotation curve of galaxy M31,especially for B514,MCGC5,H12.and B517,suggesting that most of our sample clusters do not have a kinematic association with the star-forming young disk of the *** separately fitted the absorption line indices from the updated stellar population model of Thomas et *** two different tracks of Cassisi and Padova,by applying the χ2.minimization *** fitting results show that all our sample clusters are older than 10 Gyr,and metal-poor(2.38 ≤ [Fe/H] ≤ 0.91 dex).After merging the spectroscopic metallicity of our work with the previously published ones,we extended the cluster sample out to a projected radius of 117 kpc from the galaxy's *** found the metallicity gradient exists for all the confirmed clusters with a slope of 0.02. ± 0.001 dex kpc ***,the slope turns out to be 0.018 ± 0.001 dex kpc 1 for all the halo clusters,which is much *** we only consider the outer halo clusters with rp > 2. kpc,the slope becomes 0.010 ± 0.002.dex kpc 1 and if one cluster G001 is excluded from the outer halo sample,the slope is 0.004 ± 0.002.dex kpc ***,we conclude that the metallicity gradient for M31's outer halo clusters is not significant,which agrees well with previous findings.

关键词： galaxies individual(M31) — galaxies star clusters — globular clusters general — star clusters general

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Projection Effects on Physical Parameters Obtained from solar Vector Magnetograms

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chinese Journal of Astronomy and Astrophysics 2002年第2期2卷 174-182页

作者： Hui Li Purple Mountain Observatory, chinese academy of {2., Nanjing 2.0008 national astronomical Observatories, chinese academy of {2., beijing 100012 Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 national astronomical Observatories Chinese Academy of Sciences Beijing 100012

Projection effects in Huairou solar vector magnetograms are corrected by transferring or mapping the observed vector magnetogram in the image plane to the heliographic plane (planar correction) and to the heliospheric coordinate system (spherical correction). The magnetograms after the correction are considerably dif- ferent. The planar correction and the spherical correction lead to slightly different magnetic configurations, especially when the active region involved is far from the disk center. We also discuss the effects of the corrections on magnetic activity pa- rameters, such as magnetic shear, current helicity, etc. It is shown that the neutral line is obviously distorted after the mapping. The mapping generally decreases the average shear angle on the neutral line by several degrees when the active region is in the eastern hemisphere, and increases it when in the western hemisphere. In most of the cases studied, the correction reduces the current helicity imbalance, and sometimes even changes its sign. It is found that the current helicity imbalance may change its sign in its evolution when there are apparent fluxes emerging from the lower photosphere. The corrections increase the noise level of Bz greatly, and decrease the noise level of B~ slightly. The accuracy of the magnetic field measure- ment at Huairou is estimated to be better than 2. G and 150 G for the longitudinal and the transverse component, respectively.

关键词： Sun: magnetic fields ─Sun: activity ─Sun: photosphere

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Identification of ten new Galactic HII regions

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Science china(Physics,Mechanics & Astronomy) 2010年第6期53卷 1144-1152页

作者： RUAN GuiPing 1,2.& SHI WeiBin 1,2.1 Shandong Provincial key laboratory of Optical Astronomy and {2.-Terrestrial Environment,School of Space Science and Physics,Shandong University at Weihai,Weihai 2.42.9,china 2.key laboratory of Optical Astronomy,national astronomical Observatories,chinese academy of sciences,beijing 100012.china Shandong Provincial key laboratory of Optical Astronomy and {2.-Terrestrial Environment School of Space Science and Physics Shandong University at Weihai Weihai China key laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing China

We discovered ten large HII regions in the Sino-German λ6 cm polarization survey of the Galactic plane. They have been identified according to their flat spectral indexes and the high ratio between the 60 μm infrared emission and the λ6 cm emission. The integrated flux densities as well as the sizes of these sources are given at 4800 MHz. Cross-identifications are made with other major radio catalogs.

关键词： radio continuum general-methods observational-HII regions

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A puzzle of the radio-quiet quasar PG 1407+2.5: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,{2. academy of sciences,Kunming 650011,china 2.key laboratory for the Structure and Evolution of Celestial Objects,{2. academy of sciences,Kunming 650011,china 3 Graduate University of {2. academy of sciences,beijing 100049,china chinese academy of {2. National Astronomical Observatories/Yunnan Observatory Kunming China (GRID:grid.9227.e) (ISNI:***) chinese academy of {2. Key Laboratory for the Structure and Evolution of Celestial Objects Kunming China (GRID:grid.9227.e) (ISNI:***) Graduate University of chinese academy of {2. Beijing China (GRID:grid.458514.9) chinese academy of {2. National Astronomical Observatories/Yunnan Observatory Kunming China (GRID:grid.9227.e) (ISNI:***) chinese academy of {2. Key Laboratory for the Structure and Evolution of Celestial Objects Kunming China (GRID:grid.9227.e) (ISNI:***)

PG 1407+2.5 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+2.5,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+2.5

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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, {2. 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 2.0011, china chinese academy of {2. Key Laboratory of Optical Astronomy National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***) chinese academy of {2. Key Laboratory for Particle Astrophysics Institute of High Energy Physics Beijing China (GRID:grid.9227.e) (ISNI:***) Graduate University of the chinese academy of {2. Beijing China (GRID:grid.458514.9) chinese academy of {2. Key Laboratory for Particle Astrophysics Institute of High Energy Physics Beijing China (GRID:grid.9227.e) (ISNI:***) Nanjing Normal University Department of Physics Nanjing China (GRID:grid.260474.3) (ISNI:***) chinese academy of {2. Key Laboratory of Optical Astronomy National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***)

A sample consisting of 2.1 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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Pulsars in FIRST Observations

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chinese Journal of Astronomy and Astrophysics 2002年第2期2卷 146-150页

作者： Xiang-Hua Li and Jin-Lin Han national astronomical Observatories, {2. academy of sciences, beijing 100012 national astronomical Observatories Chinese Academy of Sciences Beijing 100012

We identify 16 pulsars from the Survey of Faint Images of the Radio Sky at Twenty-cm (FIRST) at 1.4 GHz. Their positions and total flux densities are extracted from the FIRST catalog. By comparing the source positions with those in the PSR catalog, we obtain better determined positions of PSR J102.+1001, J1518+4904, J1652.2.51, and proper motion upper limits of PSR J0751+1807, J1012.5307, and J1640+2.2.. The proper motions of the other ten pulsars are consistent with the catalog values.

关键词： pulsar: general -stars: neutron

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