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Simulation Study of Network Reconfiguration and Load-balancing Method for the xinjiang astronomical observatory Data center

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Research in Astronomy and astrophysics 2022年第9期22卷 278-287页

作者： Jie Wang Hailong Zhang Na Wang Xinchen Ye Wanqiong Wang Jia Li Meng Zhang Yazhou Zhang Xu Du xinjiang astronomical observatory Chinese Academy of SciencesUrumgi 83001lChina university of Chinese Academy of Sciences Beijing 100049China national astronomical Data center Beijing 100101China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China

The xinjiang astronomical observatory Data center faces issues related to delay-affected services. As a result, these services cannot be implemented in a timely manner due to the overloading of transmission links. In this paper, the software-defined network technology is applied to the xinjiang astronomical observatory Data center Network(XAODCN). Specifically, a novel reconfiguration method is proposed to realise the software-defined xinjiang astronomical observatory Data center Network(SDXAO-DCN), and a network model is constructed. To overcome the congestion problem, a traffic load-balancing algorithm is designed for fast transmission of the service traffic by combining three factors: network structure, congestion level and transmission service. The proposed algorithm is compared with current commonly load-balancing algorithms which are used in data center to verify its efficiency. Simulation experiments show that the algorithm improved transmission performance and transmission quality for the SDXAO-DCN.

关键词： virtual observatory tools astronomical databases:miscellaneous methods:miscellaneous

Einstein Probe discovery of EP240408a: A peculiar X-ray transient with an intermediate timescale

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 222-240页

作者： Wenda Zhang Weimin Yuan Zhixing Ling Yong Chen Nanda Rea Arne Rau Zhiming Cai Huaqing Cheng Francesco Coti Zelati Lixin Dai Jingwei Hu Shumei Jia Chichuan Jin Dongyue Li Paul O’Brien Rongfeng Shen Xinwen Shu Shengli Sun Xiaojin Sun Xiaofeng Wang Lei Yang Bing Zhang Chen Zhang Shuang-Nan Zhang Yonghe Zhang Jie An David Buckley Alexis Coleiro Bertrand Cordier Liming Dou Rob Eyles-Ferris Zhou Fan Hua Feng Shaoyu Fu Johan P.U.Fynbo Lluis Galbany Saurabh W.Jha Shuaiqing Jiang Albert Kong Erik Kuulkers Weihua Lei Wenxiong Li Bifang Liu Mingjun Liu Xing Liu Yuan Liu Zhu Liu Chandreyee Maitra Alessio Marino Itumeleng Monageng Kirpal Nandra Jeremy Sanders Roberto Soria Lian Tao Junfeng Wang Song Wang Tinggui Wang Zhongxiang Wang Qingwen Wu Xuefeng Wu Dong Xu Yanjun Xu Suijian Xue Yongquan Xue Zijian Zhang Zipei Zhu Hu Zou Congying Bao Fansheng Chen Houlei Chen Tianxiang Chen Wei Chen Yehai Chen Yifan Chen Chenzhou Cui Weiwei Cui Yanfeng Dai Dongwei Fan Ju Guan Dawei Han Dongjie Hou Haibo Hu Maohai Huang Jia Huo Zhenqing Jia Bowen Jiang Ge Jin Chengkui Li Junfei Li Longhui Li Maoshun Li Wei Li Zhengda Li Tianying Lian Congzhan Liu Heyang Liu Huaqiu Liu Fangjun Lu Laidan Luo Jia Ma Xuan Mao Haiwu Pan Xin Pan Liming Song Hui Sun Yunyin Tan Qingjun Tang Yihan Tao Hao Wang Juan Wang Lei Wang Wenxin Wang Yilong Wang Yusa Wang Qinyu Wu Haitao Xu Jingjing Xu Xinpeng Xu Yunfei Xu Zhao Xu Changbin Xue Yulong Xue Ailiang Yan Haonan Yang Xiongtao Yang Yanji Yang Juan Zhang Mo Zhang Wenjie Zhang Zhen Zhang Zhen Zhang Ziliang Zhang Donghua Zhao Haisheng Zhao Xiaofan Zhao Zijian Zhao Hongyan Zhou Yilin Zhou Yuxuan Zhu Zhencai Zhu national astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences university of Chinese Academy of Sciences Key Laboratory of Particle astrophysics Institute of High Energy Physics Chinese Academy of Sciences Institute of Space Sciences (ICE) CSIC Institut d’Estudis Espacials de Catalunya (IEEC) Max Planck Institute for Extraterrestrial Physics Innovation Academy for Microsatellites Chinese Academy of Sciences Department of Physics university of Hong Kong School of Physics and Astronomy university of Leicester School of Physics and Astronomy Sun Yat-sen university Department of Physics Anhui Normal university Shanghai Institute of Technical Physics Chinese Academy of Sciences Physics Department Tsinghua university Nevada center for astrophysics university of Nevada Las Vegas Department of Physics and Astronomy university of Nevada Las Vegas South African astronomical observatory Department of Astronomy university of Cape Town Department of Physics university of the Free State Université Paris Cité CNRS Astroparticule et Cosmologie Université Paris Cité CEA Paris-Saclay IRFU/DAp-AIM Department of Astronomy Guangzhou university Cosmic Dawn center (DAWN) Niels Bohr Institute university of Copenhagen Department of Physics and Astronomy Rutgers the State university of New Jersey Institute for Cosmic Ray Research The university of Tokyo ESA/ESTEC Department of Astronomy School of Physics Huazhong university of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney Institute for Astronomy School of Physics The university of Sydney Department of Astronomy Xiamen university Institute for Frontiers in Astronomy and astrophysics Beijing Normal university Department of Astronomy university of Science and Technology School of Astronomy and Space Sciences university of Science and Technology of China Institute of Deep Space Sciences Deep Space Exploration Laboratory Department of Astronomy School of Physics and Astronomy Yunnan university Shanghai astronomical observatory Chi

We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe （EP） and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength *** new transient was first detected with Wide-field X-ray Telescope （WXT） on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 ke V,～300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 ke V,with a power-law photon index varying *** X-ray light curve shows a plateau lasting for ～4 d,followed by a steep decay till becoming undetectable ～10 d after the initial *** on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of EP240408a thus remains an *** suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of～10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

关键词： X-ray transients ${\bm~{Einstein~~Probe}}$

The detection, extraction and parameter estimation of extreme-mass-ratio inspirals with deep learning

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 86-96页

作者： Qianyun Yun Wen-Biao Han Yi-Yang Guo He Wang Minghui Du Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences Shanghai astronomical observatory Chinese Academy of Sciences School of Physics and Astronomy Shanghai Jiao Tong University School of Astronomy and Space Science University of Chinese Academy of Sciences Taiji Laboratory for Gravitational Wave Universe (Beijing/Hangzhou) University of Chinese Academy of Sciences Lanzhou center for Theoretical Physics Key Laboratory of Theoretical Physics of Gansu Province Key Laboratory of Quantum Theory and Applications of MoE Lanzhou University Institute of Theoretical Physics & Research center of Gravitation Lanzhou University International Centre for Theoretical Physics Asia-Pacific (ICTP-AP) University of Chinese Academy of Sciences (UCAS) center for Gravitational Wave Experiment National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences

One of the primary goals of space-borne gravitational wave detectors is to detect and analyze extreme-mass-ratio inspirals(EMRIs). This task is particularly challenging because EMRI signals are complex, lengthy, and faint. In this work, we introduce a2-layer convolutional neural network(CNN) approach to detect EMRI signals for space-borne detectors, achieving a true positive rate(TPR) of 96.9% at a 1% false positive rate(FPR) for signal-to-noise ratio(SNR) from 50 to 100. Especially, the key intrinsic parameters of EMRIs such as the mass, spin of the supermassive black hole(SMBH) and the initial eccentricity of the orbit can also be inferred directly by employing a neural network. The mass and spin of the SMBH can be determined at 99% and 92% respectively. This will greatly reduce the parameter spaces and computing cost for the following Bayesian parameter *** model also has a low dependency on the accuracy of the waveform model. This study underscores the potential of deep learning methods in EMRI data analysis, enabling the rapid detection of EMRI signals and efficient parameter estimation.

关键词： gravitational wave EMRIs deep-learing

Strong pulses from pulsar PSR J0034-0721

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Research in Astronomy and astrophysics 2011年第8期11卷 974-980页

作者： Adili Tuoheti Ali Esamdin Hui-Dong Hu Guo-Liang Lv Na Wang Mamat Abliz Department of Physics Xinjiang University Urumqi 830046 China xinjiang astronomical observatory Chinese Academy of Sciences Urumqi 830011 China xinjiang university-national astronomical Observatories joint center For astrophysics Urumqi 830046 China

We present an analysis of strong single pulses from PSR J0034-0721. Our observations were made using the Urumqi 25-m radio telescope at a radio frequency of 1.54 GHz. A total of 353 strong pulses were detected during eight hours of observing, The signal-to-noise ratios of the detected pulses range from 5 to 11.5. The peak fluxes of those pulses are 17 to 39 times that of the average pulse peak. The cumulative distribution of the signal-to-noise ratios of these strong pulses has a rough power-law distribution with a slope of 4.4 q- 0.5. Ten of the strong pulses arrived approximately 23 to 40 ms earlier than the average profile peak. This suggests the possibility that there are two strong pulse-emitting regions.

关键词： pulsars: PSR J0034-0721 individual pulses: strong pulses

Effects of mesoscale gravity waves on sporadic E simulated by a one-dimensional dynamic model

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Earth and Planetary Physics 2025年第1期9卷 1-9页

作者： Xu Zhou ZeZhong Li XinAn Yue LiBo Liu Key Laboratory of Earth and Planetary Physics/Heilongjiang Mohe national Geophysical observatory/Beijing national observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of Sciences(CAS)Beijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China CAS center for Excellence in Comparative Planetology/CAS Key Laboratory of Geospace Environment/Mengcheng national Geophysical observatory University of Science and Technology of ChinaHefei 230026China

In addition to being driven by tidal winds,the sporadic E(Es)layers are modulated by gravity waves(GWs),although the effects are not yet comprehensively *** this article,we discuss the effects of mesoscale GWs on the Es layers determined by using a newly developed model,MISE-1D(one-dimensional Model of Ionospheric Sporadic E),with low numerical dissipation and high *** by the wind fields resolved by the high-resolution version of the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension(WACCM-X),the MISE-1D simulation revealed that GWs significantly influence the evolution of the Es layer above 100 km but have a very limited effect at lower *** effects of GWs are diverse and complex,generally including the generation of fluctuating wavelike structures on the Es layer with frequencies similar to those of the *** mesoscale GWs can also cause increases in the density of Es layers,or they can disperse or diffuse the Es layers and increase their *** addition,the presence of GWs is a key factor in sustaining the Es layers in some cases.

关键词： sporadic E ion tidal layer gravity waves numerical simulation

Population synthesis of high mass X-ray binaries

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Research in Astronomy and astrophysics 2011年第3期11卷 327-334页

作者： Guo-Liang Lu Chun-Hua Zhu Zhao-Jun Wang School of Physics Xinjiang University .Urumqi 830046 China xinjiang university-national astronomical ObserVatories joint＇center for astrophysics Urumqi830046 China national astronomical Observatories / Urumqi observatory Chinese Academy of Sciences Urumqi 830011 China

By simulating the evolution of spin periods of magnetized neutron stars which interact with their environment in binary systems,we investigate the Galactic population of high mass X-ray binaries（HMXBs） .The number of HMXBs in the Galaxy is between 190 and 240,and their birthrate is from 5.9×10-5 yr-1 to 6.3× 10-5 *** the Corbet diagram（the positions of the spin periods *** orbital periods of HMXBs） in our model with the associated observations,we find that the stellar wind structure and the process of matter transfer are very important for understanding HMXBs.

关键词： stars:evolution—X-rays:binaries—Galaxy:stellar content

The low-latitude sodium layer:comparative data from lidar observations at Hainan,China and São Paulo,Brazil

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Earth and Planetary Physics 2025年第1期9卷 39-53页

作者： Fang Wu Jing Jiao GuoTao Yang LiFang Du ZhengKuan Liu HaoRan Zheng JiXin Guo ShaoHua Gong YaJun Zhu State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Hainan national Field Science Observation and Research observatory for Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China university of Chinese Academy of Sciences Beijing 100049China China-Brazil joint Laboratory for Space Weather NSSC/INPESão Josédos Campos 12227-010Brazil School of Physics and Electronics Engineering Hainan Normal UniversityHaikou 571158China

Physical and chemical processes observed in the mesosphere and thermosphere above the Earth’s low latitudes are complex and highly interrelated to activity in the low-latitude *** sodium detected by lidar can yield clues to dynamic and chemical processes in these spatial layers above the Earth’s *** paper is based on sodium layer data collected at two low-latitude stations,one in the northern hemisphere and one in the *** low-latitude sodium layer exhibits conspicuous seasonal variations in shape,density,and altitude;these variations are similar between Earth’s hemispheres:sodium layer density at both stations reaches its seasonal maximum in autumn and minimum in ***,maximal Na density over Brazil is greater than that over *** variations of Na density above the two low-latitude stations are also similar;at both,maxima are observed before *** variations of the Na layer over Brazil that differ from those observed in the northern hemisphere may be related to the South Atlantic Magnetic Anomaly(SAMA)or fountain *** suggest that low-latitude Na layer data may provide useful additional evidence that could significantly improve the low-latitude part of the WACCM-Na model.

关键词： metallic sodium layer seasonal variation nocturnal variation lidar

Recovering the pulse profiles and polarization position angles of some pulsars from interstellar scattering

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Research in Astronomy and astrophysics 2012年第5期12卷 529-539页

作者： Abdujappar Rusul Ali Esamdin Alim Kerim Dilnur Abdurixit Hong-Guang Wang Xiao-Ping Zheng School of Physics Science and Technology Xinjiang University Urumqi 830046 China xinjiang astronomical observatory Chinese Academy of Sciences Urumqi 830011 China xinjiang university-national astronomical observatory joint center for astrophysics Urumqi 830046 China Department of Physics Guangzhou University Guangzhou 510006 China The Institute of astrophysics Huazhong Normal University Wuhan 430079 China

Interstellar scattering causes broadening and distortion in the mean pulse profiles and polarization position angle （PPA） curves of pulsars, especially pulse profiles observed at lower frequencies. This paper implements a method to recover the pulse profiles and PPA curves of five pulsars which have obvious scattered pulse pro- files at lower frequency. It reports a simulation to show the scattering and descatter- ing of pulse profiles and PPA curves, and as a practical application the lower frequency profiles and PPA curves of PSR 1356-60, PSR 1831-03, PSR 1838＋04, PSR 1859＋03 and PSR 1946＋35 are obtained. It is found that the original pulse profiles and PPA curves can be recovered.

关键词： stars pulsar-interstellar medium

Pulsar braking:magnetodipole ***

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Science China(Physics,Mechanics & Astronomy) 2016年第1期59卷 33-44页

作者： Hao Tong xinjiang astronomical observatory Chinese Academy of Sciences

Pulsars are good clocks in the universe. One fundamental question is that why they are good clocks? This is related to the braking mechanism of pulsars. Nowadays pulsar timing is done with unprecedented accuracy. More pulsars have braking indices *** period derivative of intermittent pulsars and magnetars can vary by a factor of several. However, during pulsar studies, the magnetic dipole braking in vacuum is still often assumed. It is shown that the fundamental assumption of magnetic dipole braking(vacuum condition) does not exist and it is not consistent with the observations. The physical torque must consider the presence of the pulsar magnetosphere. Among various efforts, the wind braking model can explain many observations of pulsars and magnetars in a unified way. It is also consistent with the up-to-date observations. It is time for a paradigm shift in pulsar studies: from magnetic dipole braking to wind braking. As one alternative to the magnetospheric model, the fallback disk model is also discussed.

关键词： magnetar magnetic field neutron star pulsar wind