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Small-scale sectorial perturbation modes against the background of a pulsating model of disk-like self-gravitating systems 盘状自引力系统脉动模型背景下的小尺度扇形摄动模式
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0011
Jakhongirbek Ganiev, S. Nuritdinov
{"title":"Small-scale sectorial perturbation modes against the background of a pulsating model of disk-like self-gravitating systems","authors":"Jakhongirbek Ganiev, S. Nuritdinov","doi":"10.1515/astro-2022-0011","DOIUrl":"https://doi.org/10.1515/astro-2022-0011","url":null,"abstract":"Abstract In this work, we consider small-scale sectorial perturbation modes in a disk-like model of a radially nonstationary spiral galaxy in order to study the gravitational instabilities of these modes. Calculations of horizontal sectorial small-scale perturbation modes, such as ( m ; N ) = ( 10 ; 10 ) left(m;hspace{0.33em}N)=left(10;hspace{0.33em}10) , (11; 11), (12; 12), (13; 13), (14; 14), and (15; 15), against the background of a nonlinearly nonequilibrium anisotropic model of the self-gravitating disk have been carried out. For each of these perturbation modes, critical diagrams are plotted between the virial parameter and the degree of rotation. The growth rates of instability are calculated and compared for different values of the rotation parameter. The results of calculations and comparisons of instability regions show that with an increase in the degree of small scale, the instability region narrows as the wave numbers increase.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"92 - 98"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49265941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Can local inhomogeneity of the Universe explain the accelerating expansion? 宇宙的局部不均匀性能解释加速膨胀吗？
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0003
Sobir Turaev, S. Nuritdinov
{"title":"Can local inhomogeneity of the Universe explain the accelerating expansion?","authors":"Sobir Turaev, S. Nuritdinov","doi":"10.1515/astro-2022-0003","DOIUrl":"https://doi.org/10.1515/astro-2022-0003","url":null,"abstract":"Abstract This paper discusses the disordering of the principle of cosmology on a small scale, i.e. the possibility of interpreting the observational data of type Ia Supernovae (SNe Ia) through the inhomogeneity and anisotropy of the Universe. The expansion of the Universe may appear to be accelerating due to “dark flows”, changes in the wavelength of light passing through “voids” and clusters, or anisotropy. Different sets of cosmological data are also considered without the need for a dark energy component.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"15 - 19"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42333874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
End-of-discharge prediction for satellite lithium-ion battery based on evidential reasoning rule 基于证据推理规则的卫星锂离子电池放电终期预测
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0031
Dao Zhao, Zhijie Zhou, P. Zhang, Yijun Zhang, Haibin Qin, Shan Gao
{"title":"End-of-discharge prediction for satellite lithium-ion battery based on evidential reasoning rule","authors":"Dao Zhao, Zhijie Zhou, P. Zhang, Yijun Zhang, Haibin Qin, Shan Gao","doi":"10.1515/astro-2022-0031","DOIUrl":"https://doi.org/10.1515/astro-2022-0031","url":null,"abstract":"Abstract To ensure the safety of the power supply for an in-orbit satellite, it is of great significance to accurately predict the end-of-discharge time of lithium-ion batteries for making a reasonable flight plan. Constrained by development time and experimental environment, it is usually difficult to obtain many full discharge voltage curves of satellite batteries from ground experiments as historical data. Because of insufficient data, the prediction accuracy of the single time series prediction method is low. To solve this problem, this paper takes the voltage of the discharge process as the time series and uses the evidential reasoning rule algorithm to fuse the outputs of three typical prediction models to improve the prediction accuracy. The result can be expressed as a form of belief degree distribution with the ability to express uncertainty. Using the NASA battery dataset, the effectiveness of the proposed method is verified, and the end-of-discharge of an in-orbit satellite battery is predicted by the telemetry data.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"256 - 267"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41803925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Comparing results of real-scale time MHD modeling with observational data for first flare M 1.9 in AR 10365 ar10365第一次耀斑m1.9的实时MHD模拟结果与观测资料的比较
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0008
Alexey Vasilevich Borisenko, Igor Maksimovich Podgorny, A. Podgorny
{"title":"Comparing results of real-scale time MHD modeling with observational data for first flare M 1.9 in AR 10365","authors":"Alexey Vasilevich Borisenko, Igor Maksimovich Podgorny, A. Podgorny","doi":"10.1515/astro-2022-0008","DOIUrl":"https://doi.org/10.1515/astro-2022-0008","url":null,"abstract":"Abstract As shown in the first results of MHD simulations in the real scale of time, above the active region (AR) 10365, during the first flare M 1.9 (05/26/2003 05:34) at a height of 16–18 mm (lower corona), a singular line of magnetic field appears. The local maximum of the current density is situated on this singular line. The magnetic field in the vicinity of this singular line is the superposition of an X-type magnetic configuration and a divergent magnetic field. The accumulation of magnetic energy for solar flare with current sheet creation takes place near this singular line due to magnetic field deformation by disturbances in the X-type configuration in spite of the presence of overlaid diverging magnetic configuration. The magnetic configuration is so complicated that the singular line can be found only by using specially developed graphical system of search. The position of singular line coincides with position of source of flare radio emission at the frequency 17 GHz above AR 10365 measured by Nobeyama Radioheliograph (NoRH). Also, MHD simulation shows appearance of the singular line, in the vicinity of which X-type configuration dominates. However, apparently due to small disturbance, propagating from the photosphere, sufficient magnetic energy was not accumulated in this configuration, so the NoRH does not show the flare source of emission at the frequency 17 GHz in the place, where this singular line is situated.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"58 - 66"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45833191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Deep learning application for stellar parameters determination: I-constraining the hyperparameters 深度学习在恒星参数确定中的应用：I-约束超参数
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0007
M. Gebran, Kathleen Connick, H. Farhat, F. Paletou, I. Bentley
{"title":"Deep learning application for stellar parameters determination: I-constraining the hyperparameters","authors":"M. Gebran, Kathleen Connick, H. Farhat, F. Paletou, I. Bentley","doi":"10.1515/astro-2022-0007","DOIUrl":"https://doi.org/10.1515/astro-2022-0007","url":null,"abstract":"Abstract Machine learning is an efficient method for analysing and interpreting the increasing amount of astronomical data that are available. In this study, we show a pedagogical approach that should benefit anyone willing to experiment with deep learning techniques in the context of stellar parameter determination. Using the convolutional neural network architecture, we give a step-by-step overview of how to select the optimal parameters for deriving the most accurate values for the stellar parameters of stars: T eff {T}_{{rm{eff}}} , log g log g , [M/H], and v e sin i {v}_{e}sin i . Synthetic spectra with random noise were used to constrain this method and to mimic the observations. We found that each stellar parameter requires a different combination of network hyperparameters and the maximum accuracy reached depends on this combination as well as the signal-to-noise ratio of the observations, and the architecture of the network. We also show that this technique can be applied to other spectral-types in different wavelength ranges after the technique has been optimized.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"38 - 57"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45815183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Wide binary stars with non-coeval components 具有非同时期成分的宽双星
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0192
O. Malkov, A. Kniazev
{"title":"Wide binary stars with non-coeval components","authors":"O. Malkov, A. Kniazev","doi":"10.1515/astro-2022-0192","DOIUrl":"https://doi.org/10.1515/astro-2022-0192","url":null,"abstract":"Abstract We have the estimated masses of components of visual binaries from their spectral classification. We have selected pairs in which the less massive component looks more evolved. Spectral observations of some of these pairs were made, and at least one pair, HD 156331, was confirmed to have components of different ages. Since mass exchange is excluded in wide binaries, it means that HD 156331 can be formed by capture.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"327 - 332"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43032304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Analysis of the equilibrium points and orbits stability for the asteroid 93 Minerva 小行星93Minerva的平衡点和轨道稳定性分析
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0207
Hu Liu, Yu Jiang, A. Lang, Yajie Wang, X. Zou, J. Ping, Yutong Chang, Yongzhang Yang, Chen Zheng, Yi Lian, Jianfeng Cao
{"title":"Analysis of the equilibrium points and orbits stability for the asteroid 93 Minerva","authors":"Hu Liu, Yu Jiang, A. Lang, Yajie Wang, X. Zou, J. Ping, Yutong Chang, Yongzhang Yang, Chen Zheng, Yi Lian, Jianfeng Cao","doi":"10.1515/astro-2022-0207","DOIUrl":"https://doi.org/10.1515/astro-2022-0207","url":null,"abstract":"Abstract In this article, we study the orbital dynamics with the gravitational potential of the asteroid 93 Minerva using an irregular shape model from observations. We calculate its physical size, physical mass, surface height, and zero-velocity surface. Meanwhile, we recognize that there are five equilibrium points around Minerva, four of which are external, and one is internal. Two of the external equilibrium points are stable and near the y y -axis, while two external equilibrium points are unstable and near the x x -axis. In addition, we study the changes in the number, position, and topological case of the equilibrium points when changing the spin speed and the density. We calculate the gravitational force acceleration of the polyhedron model, and we back up our calculations by simulating the orbit of one moonlet under the gravitational force acceleration of Minerva. With the simulation result, we demonstrate the existence of stable orbits around Minerva.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"375 - 389"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46737502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Photometry and kinematics of extragalactic star-forming complexes 河外恒星形成复合体的光度测量和运动学
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0018
A. Kuzin, D. Lisitsin
{"title":"Photometry and kinematics of extragalactic star-forming complexes","authors":"A. Kuzin, D. Lisitsin","doi":"10.1515/astro-2022-0018","DOIUrl":"https://doi.org/10.1515/astro-2022-0018","url":null,"abstract":"Abstract We investigate spectral and photometric properties of extragalactic star-forming complexes (SFCs). The SFCs were selected in 17 nearby galaxies of a spiral or irregular type, having inclinations less than 45° and distances less than 15 Mpc. To identify SFCs, we developed a method based on matching sources of emission at 160 μ m 160hspace{0.33em}{rm{mu }}{rm{m}} (cold dust) and 8 μ m 8hspace{0.33em}{rm{mu }}{rm{m}} (polycyclic aromatic hydrocarbons). Using photometry in different spectral bands, correlations between SFC properties for spiral and irregular galaxies were considered. Spectral and kinematic analysis was carried out for several SFCs, and a method to detect gas motion patterns in these SFCs was suggested.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"143 - 147"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48256026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
High-altitude satellites range scheduling for urgent request utilizing reinforcement learning 基于强化学习的高海拔卫星紧急任务测距调度
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0033
Bo Ren, Zhicheng Zhu, Fan Yang, Tao Wu, Hui Yuan
{"title":"High-altitude satellites range scheduling for urgent request utilizing reinforcement learning","authors":"Bo Ren, Zhicheng Zhu, Fan Yang, Tao Wu, Hui Yuan","doi":"10.1515/astro-2022-0033","DOIUrl":"https://doi.org/10.1515/astro-2022-0033","url":null,"abstract":"Abstract High-altitude satellites are visible to more ground station antennas for longer periods of time, its requests often specify an antenna set and optional service windows, consequently leaving huge scheduling search space. The exploitation of reinforcement learning techniques provides a novel approach to the problem of high-altitude orbit satellite range scheduling. Upper sliding bound of request pass was calculated, combining customized scheduling strategy with overall antenna effectiveness, a frame of satellite range scheduling for urgent request using reinforcement learning was proposed. Simulations based on practical circumstances demonstrate the validity of the proposed method.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"268 - 275"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49353764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Research on real-time reachability evaluation for reentry vehicles based on fuzzy learning 基于模糊学习的再入飞行器可达性实时评估研究
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2022-01-01 DOI: 10.1515/astro-2022-0026
Hong Ma, Ke Xu, Shouming Sun, W. Zhang, Tao Xi
{"title":"Research on real-time reachability evaluation for reentry vehicles based on fuzzy learning","authors":"Hong Ma, Ke Xu, Shouming Sun, W. Zhang, Tao Xi","doi":"10.1515/astro-2022-0026","DOIUrl":"https://doi.org/10.1515/astro-2022-0026","url":null,"abstract":"Abstract Accurate and rapid prediction of reentry trajectory and landing point is the basis to ensure the reentry vehicle recovery and rescue, but it has high requirements for the continuity and stability of real-time monitoring and positioning data and the fidelity of the reentry prediction model. In order to solve the above contradiction, based on the theory of relative entropy and closeness in fuzzy learning, research on real-time evaluation of reentry reachability is presented in this article. With the Monte Carlo analysis data during the design and evaluation of the reentry vehicle control system, the reentry trajectory feature information base is designed. With the matching identification decision strategy between the identified trajectory and trajectory feature base, the reachability of the reentry vehicle, reachable trajectory, and landing point can be predicted. The simulation results show that by reasonably selecting the time window and using the evaluation method designed in this article, making statistics of the trajectory sequence number and frequency identified based on relative entropy and closeness method, the reachability evaluation results can be given stably, which is suitable for the real-time task evaluation of TT&C system.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":"205 - 216"},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43297284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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