Research in Astronomy and Astrophysics最新文献

SFNet: Stellar Feature Network with CWT for Stellar Spectra Recognition SFNet：用于恒星光谱识别的带 CWT 的恒星特征网络

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-18 DOI: 10.1088/1674-4527/ad7364

Hao Fu, Peng Liu, Xuan Qi and Xue Mei

引用次数: 0

Comparison of NH3 and 12CO, 13CO, C18O Molecular Lines in the Aquila Rift Cloud Complex 天鹰座裂谷云复合体中的 NH3 和 12CO、13CO、C18O 分子线比较

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-18 DOI: 10.1088/1674-4527/ad74df

Kadirya Tursun, Jarken Esimbek, Willem Baan, Toktarkhan Komesh, Xindi Tang, Gang Wu, Jianjun Zhou, Yuxin He, Dalei Li, Dongdong Zhou and Yingxiu Ma

{"title":"Comparison of NH3 and 12CO, 13CO, C18O Molecular Lines in the Aquila Rift Cloud Complex","authors":"Kadirya Tursun, Jarken Esimbek, Willem Baan, Toktarkhan Komesh, Xindi Tang, Gang Wu, Jianjun Zhou, Yuxin He, Dalei Li, Dongdong Zhou and Yingxiu Ma","doi":"10.1088/1674-4527/ad74df","DOIUrl":"https://doi.org/10.1088/1674-4527/ad74df","url":null,"abstract":"The observations of the Aquila Rift cloud complex at 23.708 and 115.271 GHz made using the Nanshan 26 m radio telescope and the 13.7 m millimeter-wavelength telescope are presented. We find that the CO(1 − 0) gas distribution is similar to the NH3 gas distribution in the Aquila Rift cloud complex. In some diffusion regions characterized by CO, we identified several dense clumps based on the distribution of detected ammonia molecular emission. Through the comparison of spectral line parameters for NH3, 13CO, and C18O, our study reveals that the line center velocities of the NH3, 13CO, and C18O lines are comparable and positively correlated, indicating that they originate from the same emission region. No significant correlation was identified for other parameters, including integrated intensity, line widths, main beam brightness temperature, as well as the column densities of NH3, 13CO, and C18O. The absolute difference in line-center velocities between the 13CO and NH3 lines is less than both the average line width of NH3 and that of 13CO. This suggests that there are no significant movements of NH3 clumps in relation to their envelopes. The velocity deviation is likely due to turbulent activity within the clumps.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"15 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251989","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

A Study of the Comets with Large Perihelion Distances C/2019 L3 (ATLAS) and C/2019 O3 (Palomar) 对近日点距离较大的彗星C/2019 L3（ATLAS）和C/2019 O3（Palomar）的研究

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-17 DOI: 10.1088/1674-4527/ad7079

Alberto S. Betzler

{"title":"A Study of the Comets with Large Perihelion Distances C/2019 L3 (ATLAS) and C/2019 O3 (Palomar)","authors":"Alberto S. Betzler","doi":"10.1088/1674-4527/ad7079","DOIUrl":"https://doi.org/10.1088/1674-4527/ad7079","url":null,"abstract":"This work analyzes the photometric data of the Oort spike comets C/2019 L3 (ATLAS) and C/2019 O3 (Palomar) obtained between 2016 and 2023 by the ATLAS network and the Belgian Olmen Observatory. The comets Palomar and ATLAS have a typical and unusually high activity level, respectively, based on the Afρ parameter corrected to phase angle zero at perihelion. The absolute magnitude of comets ATLAS and Palomar in the o-band is 4.71 ± 0.05 and 4.16 ± 0.02 respectively. The cometary activity of comets ATLAS and Palomar probably began at r > 13 au before perihelion and will end at r >14 au after perihelion, which means that they could remain active until the second half of 2026. The nucleus of comet ATLAS has a minimum radius of 7.9 km, and the nucleus of comet Palomar could be a little larger. The c − o colors of the comets ATLAS and Palomar are redder and bluer, respectively, at perihelion than the solar twin YBP 1194. These comets showed a bluish trend in the coma color with decreasing heliocentric distance. Comet Palomar probably had two outbursts after its perihelion, each releasing about 108 kg of dust. The slopes of the photometric profile of the comae of these comets were between 1 and 1.5, indicating a steady state during the observation campaign.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"16 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252024","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

The Velocity Aberration Effect of the CSST Main Survey Camera* CSST主巡天照相机的速度像差效应*

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-17 DOI: 10.1088/1674-4527/ad7078

Hui-Mei Feng, Zi-Huang Cao, Man I. Lam, Ran Li, Hao Tian, Xin Zhang, Peng Wei, Xin-Feng Li, Wei Wang, Hugh R. A. Jones, Mao-Yuan Liu and Chao Liu

{"title":"The Velocity Aberration Effect of the CSST Main Survey Camera*","authors":"Hui-Mei Feng, Zi-Huang Cao, Man I. Lam, Ran Li, Hao Tian, Xin Zhang, Peng Wei, Xin-Feng Li, Wei Wang, Hugh R. A. Jones, Mao-Yuan Liu and Chao Liu","doi":"10.1088/1674-4527/ad7078","DOIUrl":"https://doi.org/10.1088/1674-4527/ad7078","url":null,"abstract":"In this study, we conducted simulations to find the geometric aberrations expected for images taken by the Main Survey Camera of the Chinese Space Station Telescope (CSST) due to its motion. As anticipated by previous work, our findings indicate that the geometric distortion of light impacts the focal plane's apparent scale, with a more pronounced influence as the size of the focal plane increases. Our models suggest that the effect consistently influences the pixel scale in both the vertical and parallel directions. The apparent scale variation follows a sinusoidal distribution throughout one orbital period. Simulations reveal that the effect is particularly pronounced in the center of the Galaxy and gradually diminishes along the direction of ecliptic latitude. At low ecliptic latitudes, the total aberration leads to about a 0.94 pixel offset (a 20 minute exposure) and a 0.26 pixel offset (a 300 s exposure) at the edge of the field of view. Appropriate processings for the geometric effect during the CSST pre- and post-observation phases are presented.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268658","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

Understanding the Impact of H2 Diffusion Energy on the Formation Efficiency of H2 on the Interstellar Dust Grain Surface 了解 H2 扩散能对星际尘粒表面 H2 形成效率的影响

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-17 DOI: 10.1088/1674-4527/ad707a

Xiaoying Guo, Wasim Iqbal, Qiang Chang and Xiao-Hu Li

引用次数: 0

Preparation for CSST: Star-galaxy Classification using a Rotationally Invariant Supervised Machine Learning Method 为 CSST 做准备：使用旋转不变监督机器学习方法进行恒星-星系分类

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-17 DOI: 10.1088/1674-4527/ad6fe6

Shiliang Zhang, Guanwen Fang, Jie Song, Ran Li, Yizhou Gu, Zesen Lin, Chichun Zhou, Yao Dai and Xu Kong

{"title":"Preparation for CSST: Star-galaxy Classification using a Rotationally Invariant Supervised Machine Learning Method","authors":"Shiliang Zhang, Guanwen Fang, Jie Song, Ran Li, Yizhou Gu, Zesen Lin, Chichun Zhou, Yao Dai and Xu Kong","doi":"10.1088/1674-4527/ad6fe6","DOIUrl":"https://doi.org/10.1088/1674-4527/ad6fe6","url":null,"abstract":"Most existing star-galaxy classifiers depend on the reduced information from catalogs, necessitating careful data processing and feature extraction. In this study, we employ a supervised machine learning method (GoogLeNet) to automatically classify stars and galaxies in the COSMOS field. Unlike traditional machine learning methods, we introduce several preprocessing techniques, including noise reduction and the unwrapping of denoised images in polar coordinates, applied to our carefully selected samples of stars and galaxies. By dividing the selected samples into training and validation sets in an 8:2 ratio, we evaluate the performance of the GoogLeNet model in distinguishing between stars and galaxies. The results indicate that the GoogLeNet model is highly effective, achieving accuracies of 99.6% and 99.9% for stars and galaxies, respectively. Furthermore, by comparing the results with and without preprocessing, we find that preprocessing can significantly improve classification accuracy (by approximately 2.0% to 6.0%) when the images are rotated. In preparation for the future launch of the China Space Station Telescope (CSST), we also evaluate the performance of the GoogLeNet model on the CSST simulation data. These results demonstrate a high level of accuracy (approximately 99.8%), indicating that this model can be effectively utilized for future observations with the CSST.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"31 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252087","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

Leveraging the Empirical Wavelet Transform in Combination with Convolutional LSTM Neural Networks to Enhance the Accuracy of Polar Motion Prediction 将经验小波变换与卷积 LSTM 神经网络相结合，提高极地运动预测的准确性

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-17 DOI: 10.1088/1674-4527/ad74dd

Xu-Qiao Wang, Lan Du, Zhong-Kai Zhang, Ze-Jun Liu and Hao Xiang

{"title":"Leveraging the Empirical Wavelet Transform in Combination with Convolutional LSTM Neural Networks to Enhance the Accuracy of Polar Motion Prediction","authors":"Xu-Qiao Wang, Lan Du, Zhong-Kai Zhang, Ze-Jun Liu and Hao Xiang","doi":"10.1088/1674-4527/ad74dd","DOIUrl":"https://doi.org/10.1088/1674-4527/ad74dd","url":null,"abstract":"High-precision polar motion prediction is of great significance for deep space exploration and satellite navigation. Polar motion is affected by a variety of excitation factors, and nonlinear prediction methods are more suitable for polar motion prediction. In order to explore the effect of deep learning in polar motion prediction. This paper proposes a combined model based on empirical wavelet transform (EWT), Convolutional Neural Networks (CNN) and Long Short Term Memory (LSTM). By training and forecasting EOP 20C04 data, the effectiveness of the algorithm is verified, and the performance of two forecasting strategies in deep learning for polar motion prediction is explored. The results indicate that recursive multi-step prediction performs better than direct multi-step prediction for short-term forecasts within 15 days, while direct multi-step prediction is more suitable for medium and long-term forecasts. In the 365 days forecast, the mean absolute error of EWT-CNN-LSTM in the X direction and Y direction is 18.25 mas and 15.78 mas, respectively, which is 23.5% and 16.2% higher than the accuracy of Bulletin A. The results show that the algorithm has a good effect in medium and long term polar motion prediction.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"31 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252026","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

Long-term Speckle Interferometric Monitoring of Binary Systems: 2007–2023 Positional Measurements and Orbits of Seven Objects 双星系统的长期斑点干涉测量监测：2007-2023 年七个天体的位置测量和轨道研究

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-16 DOI: 10.1088/1674-4527/ad6ee1

Arina Mitrofanova, Vladimir Dyachenko, Anatoly Beskakotov, Yuri Balega, Alexander Maksimov and Denis Rastegaev

引用次数: 0

The Energy Sources and the Explosion Mechanism of Ca-rich Supernova PTF 10iuv 富钙质超新星 PTF 10iuv 的能量来源和爆炸机制

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-15 DOI: 10.1088/1674-4527/ad6bd5

Qiu-Ping Huang, 秋萍黄, Shan-Qin Wang, 善钦王, Tao Wang, 涛王, Wen-Pei Gan, 文沛甘, Deng-Wang Shi, 登旺石, Liu-Yi Wang, 浏毅王, En-Wei Liang and 恩维梁

{"title":"The Energy Sources and the Explosion Mechanism of Ca-rich Supernova PTF 10iuv","authors":"Qiu-Ping Huang, 秋萍黄, Shan-Qin Wang, 善钦王, Tao Wang, 涛王, Wen-Pei Gan, 文沛甘, Deng-Wang Shi, 登旺石, Liu-Yi Wang, 浏毅王, En-Wei Liang and 恩维梁","doi":"10.1088/1674-4527/ad6bd5","DOIUrl":"https://doi.org/10.1088/1674-4527/ad6bd5","url":null,"abstract":"In this paper, we perform the detailed modeling for the light curves (LCs) of PTF 10iuv which is a calcium-rich (Ca-rich) supernova (SN) to constrain the physical properties of its ejecta and the energy sources, as well as the explosion mechanism. We find that the 56Ni model and the 56Ni plus circumstellar interaction model fail to explain the LCs, while the four-element (56Ni, 48Cr, 52Fe, and 44Ti) model can account for the LCs. The ejecta mass of PTF 10iuv derived by the model ( M⊙) is consistent with that of the merger of a sub-Chandrasekhar mass white dwarf. The early-time LCs were mainly powered by 56Ni whose mass is ∼0.03 M⊙, while the contributions of 48Cr and 52Fe can be neglected. The derived 44Ti mass (∼0.25 M⊙) is ∼1.8 times the upper limit of the derived 44Ti mass of Ca-rich SN 2005E. We suggest that subtracting the contributions of the host-galaxy, which are unknown, and including the flux from other long-lived elements (e.g., 57Co, 55Fe, 60Co) can reduce the amount of 44Ti, and that this value can be regarded as an upper limit.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"208 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252028","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

Co-variability Between the Broad Absorption Lines and Narrow Absorption Lines 宽吸收线与窄吸收线之间的共变性

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-09-15 DOI: 10.1088/1674-4527/ad6ee2

Bo-Lin Qin, 柏霖覃, Jing Li, 静黎, Wei-Jian Lu and 伟坚陆

引用次数: 0