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Observation of the γ-ray emission from W43 with LHAASO

Science China(Physics,Mechanics & Astronomy) 2025年

作者： Zhen Cao F.Aharonian Axikegu Y.X.Bai Y.W.Bao D.Bastieri X.J.Bi Y.J.Bi W.Bian A.V.Bukevich Q.Cao W.Y.Cao Zhe Cao J.Chang J.F.Chang A.M.Chen E.S.Chen H.X.Chen Liang Chen Lin Chen Long Chen M.J.Chen M.L.Chen Q.H.Chen S.Chen S.H.Chen S.Z.Chen T.L.Chen Y.Chen N.Cheng Y.D.Cheng M.C.Chu M.Y.Cui S.W.Cui X.H.Cui Y.D.Cui B.Z.Dai H.L.Dai Z.G.Dai Danzengluobu X.Q.Dong K.K.Duan J.H.Fan Y.Z.Fan J.Fang J.H.Fang K.Fang C.F.Feng H.Feng L.Feng S.H.Feng X.T.Feng Y.Feng Y.L.Feng S.Gabici B.Gao C.D.Gao Q.Gao W.Gao W.K.Gao M.M.Ge T.T.Ge L.S.Geng G.Giacinti G.H.Gong Q.B.Gou M.H.Gu F.L.Guo J.Guo X.L.Guo Y.Q.Guo Y.Y.Guo Y.A.Han O.A.Hannuksela M.Hasan H.H.He H.N.He J.Y.He Y.He Y.K.Hor B.W.Hou C.Hou X.Hou H.B.Hu Q.Hu S.C.Hu C.Huang D.H.Huang T.Q.Huang W.J.Huang X.T.Huang X.Y.Huang Y.Huang Y.Y.Huang X.L.Ji H.Y.Jia K.Jia H.B.Jiang K.Jiang X.W.Jiang Z.J.Jiang M.Jin M.M.Kang I.Karpikov D.Khangulyan D.Kuleshov K.Kurinov B.B.Li C.M.Li Cheng Li Cong Li D.Li F.Li H.B.Li H.C.Li Jian Li Jie Li K.Li S.D.Li W.L.Li W.L.Li X.R.Li Xin Li Y.Z.Li Zhe Li Zhuo Li E.W.Liang Y.F.Liang S.J.Lin B.Liu C.Liu D.Liu D.B.Liu H.Liu H.D.Liu J.Liu J.L.Liu M.Y.Liu R.Y.Liu S.M.Liu W.Liu Y.Liu Y.N.Liu Q.Luo Y.Luo H.K.Lv B.Q.Ma L.L.Ma X.H.Ma J.R.Mao Z.Min W.Mitthumsiri H.J.Mu Y.C.Nan A.Neronov K.C.Y.Ng L.J.Ou P.Pattarakijwanich Z.Y.Pei J.C.Qi M.Y.Qi B.Q.Qiao J.J.Qin A.Raza D.Ruffolo A.Sáiz M.Saeed D.Semikoz L.Shao O.Shchegolev X.D.Sheng F.W.Shu H.C.Song Yu.V.Stenkin V.Stepanov Y.Su D.X.Sun Q.N.Sun X.N.Sun Z.B.Sun J.Takata P.H.T.Tam Q.W.Tang R.Tang Z.B.Tang W.W.Tian L.H.Wan C.Wang C.B.Wang G.W.Wang H.G.Wang H.H.Wang J.C.Wang Kai Wang Kai Wang L.P.Wang L.Y.Wang P.H.Wang R.Wang W.Wang X.G.Wang X.Y.Wang Y.Wang Y.D.Wang Y.J.Wang Z.H.Wang Z.X.Wang Zhen Wang Zheng Wang D.M.Wei J.J.Wei Y.J.Wei T.Wen C.Y.Wu H.R.Wu Q.W.Wu S.Wu X.F.Wu Y.S.Wu S.Q.Xi J.Xia G.M.Xiang D.X.Xiao G.Xiao Y.L.Xin Y.Xing D.R.Xiong Z.Xiong D.L.Xu R.F.Xu R.X.Xu W.L.Xu L.Xue D.H.Yan J.Z.Yan T.Yan C.W.Yang C.Y.Yang F.Yang F.F.Yang L.L.Yang M.J.Yang R.Z.Yang W.X.Yang Y.H.Yao Z.G.Yao L.Q.Yin N.Yin X.H.You Z.Y.You Y.H Southwest Jiaotong University School of Astronomy and space Science Nanjing University Center for Astrophysics Guangzhou University Tsung-Dao Lee Institute & School of Physics and Astronomy Shanghai Jiao Tong University Institute for Nuclear Research of Russian Academy of Sciences Hebei Normal University University of Science and technology of China LHAASO Collaboration State Key Laboratory of Particle Detection and Electronics Key Laboratory of Dark Matter and space Astronomy & Key Laboratory of Radio Astronomy Purple Mountain Observatory Chinese Academy of Sciences Research Center for Astronomical Computing Zhejiang Laboratory Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences School of Physics and Astronomy Key Laboratory of Particle Astrophysics & Experimental Physics Division & Computing Center Yunnan University Key Laboratory of Cosmic Rays (Tibet University) Ministry of Education Department of Physics The Chinese University of Hong Kong Key Laboratory of Radio Astronomy and technology National Astronomical Observatories Chinese Academy of Sciences School of Physics and Astronomy (Zhuhai) & School of Physics (Guangzhou) & Sino-French Institute of Nuclear Engineering and technology (Zhuhai) Sun Yat-sen University Institute of High Energy Physics Institute of Frontier and Interdisciplinary Science Shandong University APC Université Paris Cité CNRS/IN2P3 CEA/IRFU Observatoire de Paris Department of Engineering Physics & Department of Astronomy Tsinghua University School of Physics and Microelectronics Chinese Academy of Sciences Zhengzhou University Yunnan Observatories Chinese Academy of Sciences China Center of Advanced Science and technology College of Physics Sichuan University School of Physics Peking University Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and technology University of Chinese Academy of Sciences Guangxi University Department of Physics Faculty of Science Mahidol University Moscow Institute

In this paper, we report the detection of the very-high-energy (VHE, 100 Ge V100 TeV) γ-ray emissions from the direction of the young star-forming region W43, observed by the Large High Altitude Air Shower Observation (LHAASO). The extended γ-ray source was detected with a significance of～16σby KM2A and～17σby WCDA, respectively. The angular extension of this γ-ray source is about 0.5 degrees, corresponding to a physical size of about 50pc. We discuss the origin of the γ-ray emission and possible cosmic ray acceleration in the W43 region using multi-wavelength data. Our findings suggest that W43 is likely another young star cluster capable of accelerating cosmic rays (CRs) to at least several hundred TeV.

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Geometric Calibration and Image Quality Assessment of High Resolution Dual-Camera Satellite

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Journal of Beijing Institute of technology 2021年第2期30卷 125-138页

作者： Zhou Fang Xinrong Wang Wei Ji Meng Xu Yinan Zhang Yan Li Longfei Li space star technology Company Ltd. Beijing 100086China State Key Laboratory of space-Ground Integrated Information technology Beijing 100086China Geovis technology Company Ltd. Beijing 101399China China Academy of space technology Beijing 100094China

The evaluation of geometric calibration accuracy of high resolution satellite images has been increasingly recognized in recent *** order to evaluate geometric accuracy for dual-camera satellite images based on the ground control points(GCP),a rigorous geometric imaging model,which was based on the collinear equation of the probe directional angle and the optimized tri-axial attitude determination(TRIAD)algorithm,is *** reliable test fields in Tianjin and Jinan(China)were utilized for geometric accuracy validation of Pakistan Remote Sensing *** experimental results demonstrate a certain deviation of the on-orbit calibration result from the initial design values of the calibration ***,on-orbit geometric calibration is necessary for optical satellite *** this research,the geometrical performances including positioning accuracy without/with GCP and band registration of the dual-camera satellite were analyzed in detail,and the results of geometric image quality are assessed and *** a result,it is feasible and necessary to establish such a geometric calibration model to evaluate the geometric quality of dual-camera satellite.

关键词： geometric calibration image quality dual-camera high resolution satellite

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Covariance matrix estimation with pipeline structure in array signal processing

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The Journal of China Universities of Posts and Telecommunications 2024年第6期31卷 88-94页

作者： Chen Ligang Cai Weijie Liu Zhihui Dong Tao Zeng Hao School of Microelectronics and Communication Engineering Chongqing UniversityChongqing 400044China space star technology Co. Ltd.Beijing 100095China

Estimating the covariance matrix of the received signal is a vital step in array signal processing. The traditional estimation method is completed generally by offline way after receiving the continuous sampling snapshots, which cannot meet requirements of real-time performance. In this paper, the calculation of covariance matrix is divided into four pipeline operations, which are multiplication, accumulation, subtraction and division, *** new method leverages the parallel computing function of field programmable gate array(FPGA) to calculate the covariance matrix adopting a pipeline estimation method at each time when the array receives a new sampling snapshot. Compared with the traditional method, the new method not only improves the real-time performance, but also reduces the error in calculation caused by the rapid direction of arrival(DOA) change of the interested signal when the target is highly maneuverable.

关键词： array signal processing covariance matrix estimation pipeline real-time performance snapshot

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Radio frequency compatibility analysis for BDSBAS and GPS/WAAS

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Research in Astronomy and Astrophysics 2021年第8期21卷 235-244页

作者： Cheng Liu Wei-Guang Gao Jun Lu Yi Zhou Shan-Shan Chen Beijing institute of Tracking and Telecommunication technology Beijing 100094China BeiDou Application Research Academy of Norinco Group Beijing 100089China space star technology Beijing 100094China

Radio frequency signal compatibility is the basis of interoperability of the Satellite eBased Augmentation System(SBAS).SBAS should abide by relative international radio regulations of International Telecommunication Union(ITU) and meet the compatibility requirements of radio frequency signal between the Global Navigation Satellite System(GNSS)/SBAS,in order to avoid negative mutual *** to ITU Proposal and related reference and assumptions,the paper made simulation of signal receiving maximum power in the Bei Dou Satellite-Based Augmentation System(BDSBAS)global signal *** then,interference of BDSBAS to Global Positioning System(GPS)/WAAS(Wide Area Augmentation System) on L1/L5 bands were calculated and analyzed,with equivalent carrierto-noise ratio as the evaluation *** result shows that the carrier-to-noise ratio decrease of GPS/WAAS caused by BDSBAS B1 C and B2 a signals are extremely lower than inter-system interference of GPS/WAAS,and thus can be ignored in practical ***,BDSBAS will not cause the service performance degradation of GPS and WAAS.

关键词： space vehicles methods:data analysis celestial mechanics

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Design and Fabrication of Reflective Phase Shifter for Two-Dimensional Terahertz Beam-Scanning Reflectarray

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Chinese Journal of Electronics 2022年第3期31卷 581-588页

作者： YANG Jun YIN Mingjun GAO Haoyu YIN Zhiping YE Yang DENG Guangsheng LU Hongbo Special Display and Imaging technology Innovation Center of Anhui Province Academy of Opto-electric TechnologyHefei University of Technology Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing Guilin University of Electronic Technology space star technology Co. Ltd.

A reflective phase shifter is proposed to realize the two-dimensional beam-scanning *** reflectarray is composed of double-dipole resonant elements in which the phase shift is implemented by applying a driving voltage to the liquid crystal(LC). A 30 ×30 phase shifter sample is fabricated on a quartz substrate with a 480 μm thickness and a 4 cm × 4 cm *** to the experimental results, 0 to 360° phase shift can be achieved within the bandwidth of 5 GHz. In order to accomplish two-dimensional beam-scanning and reduce the negative impact of driving lines on the reflectarray, a new LC driving method is developed. To verify the accuracy of the proposed approach, three samples of different driving line numbers are designed using the above-mentioned phase shifter, which all have achieved a0-360° phase shift in the bandwidth of 4 GHz. Considering the influence of LC anisotropy and inhomogeneity, an improved calculation result is obtained and compared with experimental data.

关键词： liquid crystals phase shifters above-mentioned phase shifter reflective phase shifter double-dipole resonant elements submillimetre wave antennas LC anisotropy two-dimensional terahertz beam-scanning reflectarray driving voltage dipole antenna arrays scanning antennas driving line numbers LC driving method reflectarray antennas

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A SURVEY ON THE ISOPERIMETRIC PROBLEM IN RIEMANNIAN MANIFOLDS

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Acta Mathematica Scientia 2025年第1期45卷 228-236页

作者： Jiayu LI Shujing PAN School of Mathematical Sciences University of Science and Technology of ChinaHefei230026China

This is a survey of the results in[14]regarding the isoperimetric problem in the Riemannian *** consider a mean curvature type flow in the Riemannian manifold endowed with a non-trivial conformal vector field,which was firstly introduced by Guan and Li[8]in space *** flow preserves the volume of the bounded domain enclosed by a star-shaped hypersurface and decreases the area of hypersurface under certain *** will prove the long time existence and convergence of the *** a result,the isoperimetric inequality for such a domain is established.

关键词： conformal vector felds isoperimetric inequality mean curvature type fow

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CSST Dense star Field Preparation:A Framework for Astrometry and Photometry for Dense star Field Images Obtained by the China space Station Telescope(CSST)

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Research in Astronomy and Astrophysics 2024年第7期24卷 158-169页

作者： Yining Wang Rui Sun Tianyuan Deng Chenghui Zhao Peixuan Zhao Jiayi Yang Peng Jia Huigen Liu Jilin Zhou College of Electronic Information and Optical Engineering Taiyuan University of TechnologyTaiyuan 030024China School of Astronomy&space Science Nanjing UniversityNanjing 210093China Peng Cheng Lab Shenzhen 518066China

The China space Station Telescope(CSST)is a telescope with 2 m diameter,obtaining images with high quality through wide-field *** its first observation cycle,to capture time-domain observation data,the CSST is proposed to observe the Galactic halo across different *** data have significant potential for the study of properties of stars and ***,the density of stars in the Galactic center is high,and it is a well-known challenge to perform astrometry and photometry in such a dense star *** paper presents a deep learning-based framework designed to process dense star field images obtained by the CSST,which includes photometry,astrometry,and classifications of targets according to their light curve *** simulated CSST observation data,we demonstrate that this deep learning framework achieves photometry accuracy of 2%and astrometry accuracy of 0.03 pixel for stars with moderate brightness mag=24(i band),surpassing results obtained by traditional ***,the deep learning based light curve classification algorithm could pick up celestial targets whose magnitude variations are 1.7 times larger than magnitude variations brought by Poisson photon *** anticipate that our framework could be effectively used to process dense star field images obtained by the CSST.

关键词： techniques photometric-methods data analysis-astrometry

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Secure outsourcing of large matrix determinant computation

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Frontiers of Computer Science 2020年第6期14卷 141-152页

作者： Jiayang LIU Jingguo BI Mu LI Department of Computer Science and technology Tsinghua UniversityBeijing 100084China Beijing Research Institute of Telemetry Beijing 100094China Institute for Advanced Study Tsinghua UniversityBeijing 100084China space star technology Co. LtdBeijing 100086China

Cloud computing provides the capability to con-nect resource-constrained clients with a centralized and shared pool of resources,such as computational power and storage on *** matrix determinant computation is almost ubiquitous in computer science and requires large-scale data ***,techniques for securely outsourcing matrix determinant computations to untrusted servers are of utmost importance,and they have practical value as well as theoretical significance for the scientific *** this study,we propose a secure outsourcing method for large matrix determinant *** em-ploy some transformations for privacy protection based on the original matrix,including permutation and mix-row/mix-column operations,before sending the target matrix to the *** results returned from the cloud need to be de-clypled anul verified U ubtainl te cullett ***1 comparison with previously proposed algorithms,our new al-gorithm achieves a higher security level with greater cloud *** experimental results demonstrate the efficiency and effectiveness of our algorithm.

关键词： cloud computing large-scale data computation matrix determinant computation secure outsourcing

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Facial Feature Extraction Method Based on Coefficients of Variances

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Journal of Computer Science & technology 2007年第4期22卷 626-632页

作者：宋枫溪张大鹏陈才扣杨静宇 New star Research Institute of Applied technology in Hefei City Hong Kong Polytechnic University Nanjing University of Science and technology

Principal Component Analysis （PCA） and Linear Discriminant Analysis （LDA） are two popular feature extraction techniques in statistical pattern recognition field. Due to small sample size problem LDA cannot be directly applied to appearance-based face recognition tasks. As a consequence, a lot of LDA-based facial feature extraction techniques are proposed to deal with the problem one after the other. Nullspace Method is one of the most effective methods among them. The Nullspace Method tries to find a set of discriminant vectors which maximize the between-class scatter in the null space of the within-class scatter matrix. The calculation of its discriminant vectors will involve performing singular value decomposition on a high-dimensional matrix. It is generally memory- and time-consuming. Borrowing the key idea in Nullspace method and the concept of coefficient of variance in statistical analysis we present a novel facial feature extraction method, i.e., Discriminant based on Coefficient of Variance （DCV） in this paper. Experimental results performed on the FERET and AR face image databases demonstrate that DCV is a promising technique in comparison with Eigenfaces, Nullspace Method, and other state-of-the-art facial feature extraction methods.

关键词： coefficient of variation face recognition null space Gram-Schmidt orthogonalizing procedure linear feature extraction

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Topology Optimization with Aperiodic Load Fatigue Constraints Based on Bidirectional Evolutionary Structural Optimization

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Computer Modeling in Engineering & Sciences 2022年第1期130卷 499-511页

作者： Yongxin Li Guoyun Zhou Tao Chang Liming Yang Fenghe Wu Heavy-Duty Intelligent Manufacturing Equipment Innovation Center of Hebei Province School of Mechanical EngineeringYanshan UniversityQinhuangdaoChina space star technology Co. Ltd.BeijingChina

Because of descriptive nonlinearity and computational inefficiency,topology optimization with fatigue life under aperiodic loads has developed slowly.A fatigue constraint topology optimization method based on bidirectional evolutionary structural optimization(BESO)under an aperiodic load is proposed in this *** viewof the severe nonlinearity of fatigue damagewith respect to design variables,effective stress cycles are extracted through transient dynamic *** on the Miner cumulative damage theory and life requirements,a fatigue constraint is first quantified and then transformed into a stress ***,a normalized termination criterion is proposed by approximatemaximum stress measured by global stress using a P-normaggregation ***,optimization examples show that the proposed algorithm can not only meet the requirements of fatigue life but also obtain a reasonable configuration.

关键词： Topology optimization bidirectional evolutionary structural optimization aperiodic load fatigue life stress constraint

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