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

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Chinese Journal of Astronomy and Astrophysics 2002年第5期2卷 408-418页

作者： Lin-Peng Cheng, yong-heng zhao and Jian-Yan WeiNational Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 National Astronomical Observatories CAS NAOC Beijing China

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. However, the level of obscuration found in previous papers is 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.

关键词： galaxies: active - galaxies: Seyfert - polarization - star formation

The Richardson-Lucy deconvolution method to extract LAMOST 1D spectra

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Research in Astronomy and Astrophysics 2019年第10期19卷 65-68页

作者： Min Li Guang-Wei Li Ke Lv Fu-Qing Duan Hasitieer Haerken yong-heng zhao University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Space Astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences Beijing 100101 China College of Information Science and Technology Beijing Normal University Beijing 100875 China

We use the Richardson-Lucy deconvolution algorithm to extract one-dimensional(1 D) spectra from Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST) spectrum images. Compared with other deconvolution algorithms, this algorithm is much faster. The application on a real LAMOST image illustrates that the 1 D spectrum resulting from this method has a higher signal-to-noise ratio and resolution than those extracted by the LAMOST pipeline. Furthermore, our algorithm can effectively suppress the ringings that are often present in the 1 D resulting spectra generated by other deconvolution methods.

关键词： instrumentation spectrographs-methods numerical-techniques image processing-techniques spectroscopic

An empirical method to correct the saturation seen in the SOHO/MDI magnetograms

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Research in Astronomy and Astrophysics 2010年第10期10卷 1041-1048页

作者： George Zhendong Gao yong-heng zhao Yang Liu National Astronomical Observatories of China Chinese Academy of Sciences Beijing 100012 China W. W. Hansen Experimental Physics Laboratory Stanford University Stanford CA 94305-4085 USA

The magnetic field of the umbrae is sometimes found to be saturated in the magnetograms taken by the Michelson Doppler Imager （MDI） onboard the Solar and Heliospheric Observatory （SOHO）. It is suggested that the combination of the low intensity of sunspot umbrae and the limitation of the 15-bit onboard numerical data acquisition leads to this saturation. In this paper, we propose to use the MDI＇s intensity data to correct this saturation. This method is based on the well-established relationship between the continuum intensity and the magnetic field （the so-called I-B relationship）. A comparison between the corrected magnetic field and the data taken by the Stokes-Polarimeter of the Solar Optical Telescope （SOT/SP） onboard Hinode shows a reasonable agreement, suggesting that this correction is effective.

关键词： Sun solar magnetic field -- Sun MDI magnetograms -- Sun Saturation

LAMOST CCD camera-control system based on RTS2

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Research in Astronomy and Astrophysics 2018年第5期18卷 69-82页

作者： Yuan Tian Zheng Wang Jian Li Zi-Huang Cao Wei Dai Shou-Lin Wei yong-heng zhao Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of SciencesBeijing 100101 China Computer Technology Application Key Lab of Yunnan Province Kunming University of Science and TechnologyKunming 650500 China University of Chinese Academy of Sciences Beijing 100049 China

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） is the largest existing spectroscopic survey telescope, having 32 scientific charge-coupled-device（CCD） cameras for acquiring spectra. Stability and automation of the camera-control software are essential, but cannot be provided by the existing system. The Remote Telescope System 2 nd Version（RTS2） is an open-source and automatic observatory-control system. However, all previous RTS2 applications were developed for small telescopes. This paper focuses on implementation of an RTS2-based camera-control system for the 32 CCDs of LAMOST. A virtual camera module inherited from the RTS2 camera module is built as a device component working on the RTS2 framework. To improve the controllability and robustness, a virtualized layer is designed using the master-slave software paradigm, and the virtual camera module is mapped to the 32 real cameras of LAMOST. The new system is deployed in the actual environment and experimentally tested. Finally, multiple observations are conducted using this new RTS2-frameworkbased control system. The new camera-control system is found to satisfy the requirements for automatic camera control in LAMOST. This is the first time that RTS2 has been applied to a large telescope, and provides a referential solution for full RTS2 introduction to the LAMOST observatory control system.

关键词： telescopes - techniques imaging spectroscopy - methods observational - instrumentation detectors

19 low mass hypervelocity star candidates from the first data release of the LAMOST survey

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Research in Astronomy and Astrophysics 2015年第8期15卷 1364-1377页

作者： Yin-Bi Li A-Li Luo Gang zhao You-Jun Lu Peng Wei Bing Du Xiang Li yong-heng zhao Zhan-Wen Han Bo Wang Yue Wu yong Zhang yong-Hui Hou Yue-Fei Wang Ming Yang Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China State Key Laboratory of High-end Server & Storage Technology Jinan 250510 China Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Nanjing Institute of Astronomical Optics & Technology National Astronomical Observatories Chinese Academy of Sciences Nanjing 210042 China

Hypervelocity stars are believed to be ejected out from the Galactic center through dynamical interactions between（binary） stars and the central supermassive black hole（s）. In this paper, we report 19 low mass F/G/K type hypervelocity star candidates from over one million stars found in the first data release of the LAMOST regular survey. We determine the unbound probability for each candidate using a MonteCarlo simulation by assuming a non-Gaussian proper-motion error distribution, and Gaussian heliocentric distance and radial velocity error distributions. The simulation results show that all the candidates have unbound possibilities over 50% as expected,and one of them may even exceed escape velocity with over 90% probability. In addition, we compare the metallicities of our candidates with the metallicity distribution functions of the Galactic bulge, disk, halo and globular clusters, and conclude that the Galactic bulge or disk is likely the birth place for our candidates.

关键词： stars: low-mass—stars: kinematics and dynamics—Galaxy: abundances—stars: fundamental parameters—stars: distances

LAMOST medium-resolution spectral survey of Galactic nebulae(LAMOST-MRS-N):subtraction of geocoronal Hαemission

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Research in Astronomy and Astrophysics 2021年第11期21卷 89-97页

作者： Wei Zhang Hong Wu Chao-Jian Wu Juan-Juan Ren Jian-Jun Chen Chih-Hao Hsia Yu-Zhong Wu Hui Zhu Jian-Rong Shi Zhong-Rui Bai zhao-Xiang Qi yong-heng zhao yong-Hui Hou CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyTaipaMacaoChina Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

We introduce a method of subtracting geocoronal Hαemissions from the spectra of LAMOST medium-resolution spectral survey of Galactic nebulae(LAMOST-MRS-N).The flux ratios of the Hαsky line to the adjacent OHλ6554 single line do not show a pattern or gradient distribution in a *** interestingly,the ratio is well correlated to solar altitude,which is the angle of the Sun relative to the Earth’s *** is found that the ratio decreases from 0.8 to 0.2 with the decreasing solar altitude from–17 to–73 *** on this relation,which is described by a linear function,we can construct the Hαsky component and subtract it from the science *** method has been applied to the LAMOST-MRSN data,and the contamination level of the Hαsky to nebula is reduced from 40%to less than 10%.The new generated spectra will significantly improve the accuracy of the classifications and the measurements of physical parameters of Galactic nebulae.

关键词： techniques:spectroscopic instrumentation:spectrographs ISM:general

The discovery of 64 luminous infrared galaxies in the LAMOST Complete Spectroscopic Survey of Pointing Area at the Southern Galactic Cap

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Research in Astronomy and Astrophysics 2015年第8期15卷 1424-1437页

作者： Man I Lam Hong Wu Ming Yang Yi-Nan Zhu Jian-Rong Shi Hao-Tong Zhang A-Li Luo Shi-Yin Shen yong Zhang yong-Hui Hou Guang-Wei Li yong-heng zhao Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of Sciences Nanjing Institute of Astronomical Optics & Technology National Astronomical ObservatoriesChinese Academy of Sciences

We report the discovery of 64 luminous infrared galaxies, based on new observations of 20 square degrees from the LAMOST Complete Spectroscopic Survey of Pointing Area at the Southern Galactic Cap and the WISE 22 μm catalog from the AllW ISE Data Release. Half of them are classified as late-type spirals and the others are classified as peculiar/compact galaxies. The peculiar/compact galaxies tend to exhibit higher luminosities and lower stellar masses. We also separate AGNs from HII galaxies in a simple way by examining LAMOST spectra. Those cases show that host AGNs are easily distinguished from others in the mid-infrared color-color diagrams.

关键词： galaxies: statistic—galaxies: structure—galaxies: starburst—galaxies: spiral—galaxies: interactions—infrared: galaxies

On the Black Hole - Bulge Mass Ratios in Narrow-Line Seyfert 1 Galaxies

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Chinese Journal of Astronomy and Astrophysics 2003年第2期3卷 119-124页

作者： Wei-Hao Bian and yong-heng zhao1 National Astronomical Observatories, Chinese Academy of Sciences, Beijing 1000122 Department of Physics, Nanjing Normal University, Nanjing 210097 National Astronomical Observatories Chinese Academy of Sciences 北京 100012

We present estimated ratios of the central black hole mass to the bulge mass (Mbh/Mbulge) for 15 Narrow Line Seyfert 1 galaxies (NLS1s). It is found that NLS1s apparently have lower mass ratios: the average mass ratio is about 1 × 10-4 with a spread of 2, which is one order of magnitude lower than for Broad Line AGNs and quiescent galaxies. This lower value, as compared to that established essentially for all other types of galaxies, can be accounted for by an underestimation of the black hole masses and an overestimation of the bulge masses in the NLS1s.

关键词： galaxies: active - galaxies: nuclei - galaxies: bulges - quasars -galaxies: Seyfert

Moon night sky brightness simulation for the Xinglong station

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Research in Astronomy and Astrophysics 2013年第10期13卷 1255-1268页

作者： Song Yao Hao-Tong Zhang Hai-Long Yuan yong-heng zhao Yi-Qiao Dong Zhong-Rui Bai Li-Cai Deng Ya-Juan Lei Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

Using a sky brightness monitor at the Xinglong station of National Astronomical Observatories,Chinese Academy of Sciences,we collected data from22 dark clear nights and 90 moon *** first measured the sky brightness variation with time for dark nights and found a clear correlation between sky brightness and human *** with a modified sky brightness model of moon nights and data from these nights,we derived the typical value for several important parameters in the *** these results,we calculated the sky brightness distribution under a given moon condition for the Xinglong ***,we simulated the sky brightness distribution of a moon night for a telescope with a 5 field of view（such as LAMOST）.These simulations will be helpful for determining the limiting magnitude and exposure time,as well as planning the survey for LAMOST during moon nights.

关键词： Moon scattering site testing telescopes