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On the Red Edge of the δ Scuti Instability Strip

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chinese Journal of Astronomy and Astrophysics 2002年第5期2卷 441-448页

作者： Yan Xu Zhi-Ping li li-Cai Deng Da-Run Xiong national Astronomical Observatories Chinese Academy of SciencesBeijing 100012 Department of Physics Tianjin Normal UniversityTianjin 300073 purple mountain observatory Chinese Academy of SciencesNanjing 210008

The δ Scuti star catalogue is used to derive the observational locations of such stars on the HR diagram. The theoretical and observational instability strips are compared to check the theoretical red edge obtained by considering nonlocal time-dependent convection theory. The observational instability strip almost overlaps with the theoretical one, but the observed blue and red envelopes are hotter than the theoretical edges. The distribution of δ Scuti stars in the pulsation strip is not uniform.

关键词： stars: variables: δ Sct - stars: oscillations ?stars: HR diagram

Data reduction and calibration of the FMG onboard ASO-S

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Research in Astronomy and Astrophysics 2019年第11期19卷 63-78页

作者： Jiang-Tao Su Xian-Yong Bai Jie Chen Jing-Jing Guo Suo liu Xiao-Fan Wang Hai-Qing Xu Xiao Yang Yong-liang Song Yuan-Yong Deng Kai-Fan Ji Lei Deng Yu Huang hui li Wei-Qun Gan Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space sciences University of Chinese Academy of SciencesBeijing 100049China Yunnan Observatories Chinese Academy of SciencesKunming 650216China Innovation academy for Microsatellites of chinese academy of sciences Shanghai 201203China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210008China

The Full-disk vector Magneto Graph(FMG)instrument will carry out polarization observations at one wavelength position of the Fe I 53.4.179?spectral *** paper describes how to choose this single wavelength position,the relevant data-processing and the magnetic field calibrations based on the measured polarization signals at one single wavelength *** is found that solar radial Doppler velocity,which can cause the spectral line to shift,is a disadvantageous factor for the linear calibration at one wavelength *** at two symmetric wavelength positions may significantly reduce the wavelength shift effect(~75%),but simulations show that such polarization signals located at the solar limbs(e.g.,beyond the longitude range of±3.°)are not free from the effect *** future work,we plan to apply machine learning techniques to calibrate vector magnetic fields,or employ full Stokes parameter profile inversion techniques to obtain accurate vector magnetic fields,in order to complement the linear calibration at the single wavelength position.

关键词： Sun photosphere-Sun magnetic fields-Sun calibration

LAMOST MRS-N Observation of the W80 Region

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Research in Astronomy and Astrophysics 2022年第7期22卷 161-175页

作者： Yao li Chao-Jian Wu Yong-Qiang Yao Wei Zhang Jia Yin Juan-Juan Ren Chih-Hao Hsia Rui Zhuang Jian-Jun Chen Yu-Zhong Wu hui Zhu Bin li Yong-hui Hou Meng-Yuan Yao Hong Wu national Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese 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 University of Science and Technology beijing Beijing 100083China purple mountain observatory Chinese Academy of SciencesNanjing 210008China University of Science and Technology of China Hefei 230026China nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China China academy of Aerospace Electronics Technology Beijing 100094China

The spectral observations and analysis for the W80 region are presented by using the data of Medium-Resolution Spectroscopic Survey of Nebulae(MRS-N) with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST).A total of 2982 high-quality nebular spectra have been obtained in the 20 square degree field of view which covers the W80 complex,and the largest sample of spectral data has been established for the first *** relative intensities,radial velocities(RVs),and full widths at half maximum(FWHMs) are measured with the high spectral resolution of LAMOST MRS-N,for Ha λ6563.,[NⅡ] λλ6548 A,6584 A,and [SⅡ] λλ6716A,673. A emission *** the field of view of the whole W80 region,the strongest line emissions are found to be consistent with the bright nebulae NGC 7000,IC 5070,and LBN 3.1,and weak line emissions also exist in the Middle Region,where no bright nebulae are detected by the wide-band optical *** large-scale spectral observations of the W80 region reveal the systematic spatial variations of RVs and FWHMs,and several unique structural features.A "curved feature" to the east of NGC 7000,and a "jet feature" to the west of LBN 3.1 are detected to be showing larger RVs.A "wider FWHM region" is identified in the eastern part of NGC *** variations of[S Ⅱ]/Ha ratios display a gradient from southwest to northeast in the NGC 7000 region,and manifest a ring shape around the "W80 bubble" ionized by an O-type star in *** spectral and multi-band observations are guaranteed to investigate in detail the structural features.

关键词： surveys (ISM:)HII regions ISM:molecules ISM:bubbles methods:statistical

Probing the Progenitor of High-z Short-duration GRB 201221D and its Possible Bulk Acceleration in Prompt Emission

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Research in Astronomy and Astrophysics 2022年第7期22卷 176-190页

作者： Hao-Yu Yuan Hou-Jun Lü Ye li Bin-Bin Zhang hui Sun Jared Rice Jun Yang En-Wei liang Guangxi Key Laboratory for Relativistic Astrophysics Department of PhysicsGuangxi UniversityNanning 530004China purple mountain observatory Chinese Academy of SciencesNanjing 210008China Key Laboratory of Modern Astronomy and Astrophysics(nanjing University) Ministry of EducationNanjing 210093China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Mathematics and Physical Science Southwestern Adventist UniversityKeeneTX 76059USA

The growing observed evidence shows that the long-and short-duration gamma-ray bursts(GRBs) originate from massive star core-collapse and the merger of compact stars,*** 201221 D is a short-duration GRB lasting~0.1 s without extended emission at high redshift z=*** analyzing data observed with the Swift/BAT and Fermi/GBM,we find that a cutoff power-law model can adequately fit the spectrum with a soft E=113.eV,and isotropic energy E=1.3.× *** order to reveal the possible physical origin of GRB 201221 D,we adopted multi-wavelength criteria(e.g.,Amati relation,ε-parameter,amplitude parameter,local event rate density,luminosity function,and properties of the host galaxy),and find that most of the observations of GRB 201221 D favor a compact star merger ***,we find that α is larger than 2+βin the prompt emission phase which suggests that the emission region is possibly undergoing acceleration during the prompt emission phase with a Poynting-flux-dominated jet.

关键词： (stars:)gamma-ray burst:individual(GRB 201221D) stars:massive acceleration of particles

Optical observations of liGO source GW 170817 by the Antarctic Survey Telescopes at Dome A,Antarctica

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Science Bulletin 2017年第21期62卷 1433-1438页

作者： lei hu xuefeng wu igor andreoni michael c.b.ashley jeff cooke xiangqun cui fujia du zigao dai bozhong gu yi hu haiping lu xiaoyan li zhengyang li ensi liang liangduan liu bin ma zhaohui shang tianrui sun n.b.suntzeff charling tao syed a.uddin lifan wang xiaofeng wang haikun wen di xiao jin xu ji yang shihai yang xiangyan yuan hongyan zhou hui zhang jilin zhou zonghong zhu purple mountain observatory chinese academy of sciencesNanjing 210008China chinese center for antarctic astronomy Nanjing 210008China school of astronomy and space sciences university of science and technology of chinaHefei 230029China centre for astrophysics and supercomputing swinburne university of technologyHawthornVIC3122Australia the australian research council centre of excellence for gravitational wave discovery(ozgrav) Australia australian astronomical observatory north rydensw 2113Australia school of physics university of new south walesnsw 2052Australia the australian research council centre of excellence for all-sky astrophysics(caastro) Australia nanjing institute of astronomical optics and technology nanjing 210042China school of astronomy and space science and key laboratory of modern astronomy and astrophysics in ministry of education nanjing universitynanjing 210093China national astronomical observatories chinese academy of sciencesBeijing 100012China department of physics tianjin normal universitytianjin 300074china shanghai key laboratory for astrophysics shanghai normal universityshanghai 200234China george p.and cynthia woods mitchell institute for fundamental physics&astronomy texas a.&m.universitydepartment of physics and astronomy4242 tamucollege stationTX 77843USA aix marseille univ CNRS/N2P3CPPMmarseilleFrance physics department and tsinghua center for astrophysics(thca) tsinghua universityBeijing 100084China polar research institute of china shanghai 200136china department of astronomy beijing normal universitybeijing 100875china school of physics and technology wuhan universitywuhan 430072china

The liGO detection of gravitational waves(GW) from merging black holes in 2015 marked the beginning of a new era in observational astronomy. The detection of an electromagnetic signal from a GW source is the critical next step to explore in detail the physics involved. The Antarctic Survey Telescopes(AST3.,located at Dome A, Antarctica, is uniquely situated for rapid response time-domain astronomy with its continuous night-time coverage during the austral winter. We report optical observations of the GW source(GW 170817) in the nearby galaxy NGC 4993.using AST3. The data show a rapidly fading transient at around 1 day after the GW trigger, with the i-band magnitude declining from 17:23.± 0:13.magnitude to 17:72 ± 0:09 magnitude in ~1:8 h. The brightness and time evolution of the optical transient associated with GW 170817 are broadly consistent with the predictions of models involving merging binary neutron stars. We infer from our data that the merging process ejected about ~10^(-2) solar mass of radioactive material at a speed of up to 3.% the speed of light.

关键词： Gravitational waves Binary neutron stars Gamma-ray bursts

Testing and data reduction of the chinese Small Telescope Array(CSTAR) for Dome A,Antarctica

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Research in Astronomy and Astrophysics 2010年第3期10卷 279-290页

作者： Xu Zhou Zhen-Yu Wu Zhao-Ji Jiang Xiang-Qun Cui Long-Long Feng Xue-Fei Gong Jing-Yao Hu Qi-Sheng li Gen-Rong liu Jun Ma Jia-li Wang li-Fan Wang Jiang-Hua Wu li-Rong Xia Jun Yan Xiang-Yan Yuag Feng-Xiang Zhai Ru Zhang Zhen-Xi Zhu national Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China nanjing Institute of Astronomical Optics ＆ Technology National Astronomical Observatories Chinese Academy of Sciences Nanjing 210042 China purple mountainobservatory Chinese Academy of Sciences Nanjing 210008 China chinese Center for Antarctic Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China

The chinese Small Telescope Array （CSTAR） is the first chinese astronomical instrument on the Antarctic ice cap. The low temperature and low pressure testing of the data acquisition system was carried out in a laboratory refrigerator and on the 4500 m Pamirs high plateau, respectively. The results from the final four nights of test observations demonstrated that CSTAR was ready for operation at Dome A, Antarctica. In this paper, we present a description of CSTAR and the performance derived from the test observations.

关键词： instrumentation: detectors -- techniques: photometric -- stars: variables

Envelope Soliton in Multi-ion Plasma and Ion-Ion Hybrid Wave Excited by Energetic Electron Beam

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chinese Physics Letters 2001年第4期18卷 553-555页

作者： WANG De-Yu HUANG Guang-li purple mountain observatory Chinese Academy of SciencesNanjing 210008 national Astronomical Observatories Chinese Academy of SciencesBeijing 100012

Another envelope soliton event below the H+gyrofrequency and localized density depletion was discovered in low auroral region(~1760 km)by Freja *** envelope soliton has a characteristic frequency at~190 Hz,which is also closed to the resonance frequency of hydrogen ion-oxygen ion hybrid *** event is correlated in time with the observations of the sharp increase of the ratio of oxygen ion density to hydrogen and with the electrons energization along the magnetic field.A theoretical model on the ion-ion hybrid wave excited by energetic electron beam has also been *** is found that the ion-ion hybrid wave is mainly excited by the Cherenkov instability in auroral region.

关键词： field. wave. soliton

Efficient turbulent compressible convection in the deep stellar atmosphere

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chinese Journal of Astronomy and Astrophysics 2009年第1期9卷 102-114页

作者： Chun-lin Tian li-Cai Deng Kwing-Lam Chan Da-Run Xiong national Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Graduate University of chinese academy of sciences Beijing 100049 China Department of Mathematics Hong Kong University of Science and Technology Hong Kong China purple mountain observatory Chinese Academy of Sciences Nanjing 210008 China

We report on an application of gas-kinetic BGK scheme to the computation of turbulent compressible convection in the stellar interior. After incorporating the Sub-grid Scale （SGS） turbulence model into the BGK scheme, we tested the effects of numerical parameters on the quantitative relationships among the thermodynamic variables, their fluctuations and correlations in a very deep, initially gravity-stratified stellar atmosphere. Comparison indicates that the thermal properties and dynamic properties are dominated by different aspects of numerical models separately. An adjustable Deardorff constant in the SGS model cu, = 0.25 and an amplitude of artificial viscosity in the gas-kinetic BGK scheme C2 = 0 are appropriate for the current study. We also calculated the densityweighted auto- and cross-correlation functions in Xiong＇s turbulent stellar convection theory based on which the gradient type of models of the non-local transport and the anisotropy of the turbulence were preliminarily studied. No universal relations or constant parameters were found for these models.

关键词： convection -- hydrodynamic -- turbulence -- method: numerical -- stars atmosphere

Diagnosing physical conditions near the flare energy-release sites from observations of solar microwave typeⅢbursts

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Research in Astronomy and Astrophysics 2016年第5期16卷 109-116页

作者： Bao-lin Tan Marian Karlicky Hana Mészárosová Guang-li Huang Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing100012China Astronomical Institute of the academy of sciences of the Czech Republic CZ-25165 Ond~ejovCzech Republic purple mountain observatory Chinese Academy of SciencesNanjing 210008China

In the physics of solar flares, it is crucial to diagnose the physical conditions near the flare energy- release sites. However, so far it is unclear how to diagnose these physical conditions. A solar microwave type III burst is believed to be a sensitive signature of primary energy release and electron accelerations in solar flares. This work takes into account the effect of the magnetic field on the plasma density and develops a set of formulas which can be used to estimate the plasma density, temperature, magnetic field near the magnetic reconnection site and particle acceleration region, and the velocity and energy of electron beams. We apply these formulas to three groups of microwave type III pairs in an X-class flare, and obtained some reasonable and interesting results. This method can be applied to other microwave type III bursts to diagnose the physical conditions of source regions, and provide some basic information to understand the intrinsic nature and fundamental processes occurring near the flare energy-release sites.

关键词： Sun: radio radiation -- Sun: flares -- Sun: corona