Research in Astronomy and Astrophysics最新文献_第4页

Simulating the Escaping Atmosphere of GJ436 b with two-fluid Magnetohydrodynamic Models 利用双流体磁流体动力学模型模拟 GJ436 b 的逃逸大气层

Research in Astronomy and Astrophysics Pub Date : 2024-05-06 DOI: 10.1088/1674-4527/ad47de

Lei Xing, Jianheng Guo, Chuyuan Yang, Dongdong Yan

{"title":"Simulating the Escaping Atmosphere of GJ436 b with two-fluid Magnetohydrodynamic Models","authors":"Lei Xing, Jianheng Guo, Chuyuan Yang, Dongdong Yan","doi":"10.1088/1674-4527/ad47de","DOIUrl":"https://doi.org/10.1088/1674-4527/ad47de","url":null,"abstract":"\u0000 Observations of transmission spectra reveal that hot Jupiters and Neptunes are likely to possess escaping atmospheres driven by stellar radiation. Numerous models predict that magnetic fields may exert significant influences on the atmospheres of hot planets. Generally, the escaping atmospheres are not entirely ionized, and magnetic fields only directly affect the escape of ionized components within them. Considering the chemical reactions between ionized components and neutral atoms, as well as collision processes, magnetic fields indirectly impact the escape of neutral atoms, thereby influencing the detection signals of planetary atmospheres in transmission spectra. In order to simulate this process, we developed a magneto-hydrodynamic multi-fluid model based on MHD code PLUTO. As an initial exploration, we investigated the impact of magnetic fields on the decoupling of H+ and H in the escaping atmosphere of the hot Neptune GJ436 b. Due to the strong resonant interactions between H and H+ , the coupling between them is tight even if the magnetic field is strong. Of course, alternatively, our work also suggests that merging H and H+ into a single flow can be a reasonable assumption in MHD simulations of escaping atmospheres. However, our simulation results indicate that under the influence of magnetic fields, there are noticeable regional differences in the decoupling of H+ and H. With the increase of magnetic field strength, the degree of decoupling also increases. For heavier particles such as O, the decoupling between O and H+ is more pronounced. Our findings provide important insights for future studies on the decoupling processes of heavy atoms in the escaping atmospheres of hot Jupiters and hot Neptunes under the influence of magnetic fields.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"38 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141009366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optical Extinctions of Inter-Arm Molecular Clouds in M31: A Pilot Study for the Upcoming CSST Observations M31 中臂间分子云的光学萃取：即将进行的 CSST 观测的试点研究

Research in Astronomy and Astrophysics Pub Date : 2024-05-06 DOI: 10.1088/1674-4527/ad47dc

Cailing Chen, Zheng Zheng, Chao-Wei Tsai, Sihan Jiao, Jing Tang, Jingwen Wu, Di Li, Yun Zheng, Linjing Feng, Yujiao Yang, Yuan Liang

{"title":"Optical Extinctions of Inter-Arm Molecular Clouds in M31: A Pilot Study for the Upcoming CSST Observations","authors":"Cailing Chen, Zheng Zheng, Chao-Wei Tsai, Sihan Jiao, Jing Tang, Jingwen Wu, Di Li, Yun Zheng, Linjing Feng, Yujiao Yang, Yuan Liang","doi":"10.1088/1674-4527/ad47dc","DOIUrl":"https://doi.org/10.1088/1674-4527/ad47dc","url":null,"abstract":"\u0000 Recent Submillimeter dust thermal emission observations have unveiled a significant number of inter-arm massive molecular clouds in M31. However, the effectiveness of this technique is limited to its sensitivity, making it challenging to study more distant galaxies. This study introduces an alternative approach, utilizing optical extinctions derived from space-based telescopes, with a focus on the forthcoming China Space Station Telescope (CSST). We first demonstrate the capability of this method by constructing dust extinction maps for 17 inter-arm massive molecular clouds in M31 using the Panchromatic Hubble Andromeda Treasury (PHAT) data. Our analysis reveals that inter-arm massive molecular clouds with an optical extinction (AV) greater than 1.6 magnitudes exhibit a notable AV excess, facilitating their identification. The majority of these inter-arm massive molecular clouds show an AV around 1 magnitude, aligning with measurements from our JCMT data. Further validation using a mock CSST RGB star catalog confirms the method’s effectiveness. We show that the derived AV values using CSST z and y photometries align more closely with the input values. Molecular clouds with AV > 1.6 can also be identified using the CSST mock data. We thus claim that future CSST observation cloud provide an effective way for the detection of inter-arm massive molecular clouds with significant optical extinction in nearby galaxies.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"58 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141008856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mid-infrared Period--Luminosity relations of Gaia DR3 Long Period Variables 盖亚 DR3 长周期变星的中红外周期-光度关系

Research in Astronomy and Astrophysics Pub Date : 2024-05-01 DOI: 10.1088/1674-4527/ad462c

Xiaohan Chen, Xiaodian Chen, Licai Deng, Shu Wang, Tianlu Chen

{"title":"Mid-infrared Period--Luminosity relations of Gaia DR3 Long Period Variables","authors":"Xiaohan Chen, Xiaodian Chen, Licai Deng, Shu Wang, Tianlu Chen","doi":"10.1088/1674-4527/ad462c","DOIUrl":"https://doi.org/10.1088/1674-4527/ad462c","url":null,"abstract":"\u0000 Long period variable stars (LPVs) are very promising distance indicators in the infrared bands. We selected asymptotic giant branch (AGB) stars in the Large and Small Magellanic Cloud (LMC and SMC) from the Gaia Data Release 3 (DR3) LPV catalog, and classified them into oxygen-rich (O-rich) and carbon-rich (C-rich) AGB stars. Using the WISE database, we determined the $W1$- and $W2$-bands Period--Luminosity relations (PLRs) for each pulsation-mode sequence of AGB stars. The dispersion of the PLRs of O-rich AGB stars in sequences $rm{C^{'}}$ and C is relatively small, around 0.14 mag. The PLRs of LMC and SMC are consistent in each sequence. % while due to selection effect, {bf the PLR zero points} of Milky Way are significantly underestimated. In the $W2$ band, the PLR of large-amplitude C-rich AGB stars is steeper than that of small-amplitude C-rich AGB stars, due to their more circumstellar dust. By two methods, we find that some PLR sequences of O-rich AGB stars in the LMC are dependent on metallicity. The coefficients of the metallicity effect are $beta = -0.533 pm 0.213 $ mag/dex and $beta= -0.767 pm 0.158$ mag/dex for sequence C in $W1$ and $W2$ bands, respectively. The significance of the metallicity effect in $W1$ band for the four sequences is $2.2-3.5 sigma$. Both of these imply that distance measurements using O-rich Mira maybe need to take the metallicity effect into account.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141026057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multiwavelength Observations of the Infrared Dust Bubble N75 and its Surroundings 对红外尘埃泡 N75 及其周围环境的多波长观测

Research in Astronomy and Astrophysics Pub Date : 2024-03-20 DOI: 10.1088/1674-4527/ad3618

Quan-Ling Cui, Chuan-peng Zhang, Junjie Wang

引用次数: 0

Astronomical Test with CMOS on the 60-cm Telescope at the Xinglong Observatory, NAOC 国家天文台兴隆观测站 60 厘米望远镜 CMOS 天文测试

Research in Astronomy and Astrophysics Pub Date : 2024-03-19 DOI: 10.1088/1674-4527/ad359a

Hai-Yang Mu, Zhou Fan, Yinan Zhu, Yu Zhang, Hong Wu

引用次数: 0

Accelerating Asteroidal Period and Pole Inversion from Multiple Lightcurves Using Parallel Differential Evolution and Cellinoid Shape Model 利用并行差分进化和蜂窝体形状模型，从多条光曲线加速小行星周期和极点反演

Research in Astronomy and Astrophysics Pub Date : 2024-03-17 DOI: 10.1088/1674-4527/ad34bb

Yong-Xiong Zhang, Wen-Xiu Guo, Xiao-Ping Lu, Hua Zheng, Hai-bin Zhao, Jun Tian, Wei-Lin Wang

{"title":"Accelerating Asteroidal Period and Pole Inversion from Multiple Lightcurves Using Parallel Differential Evolution and Cellinoid Shape Model","authors":"Yong-Xiong Zhang, Wen-Xiu Guo, Xiao-Ping Lu, Hua Zheng, Hai-bin Zhao, Jun Tian, Wei-Lin Wang","doi":"10.1088/1674-4527/ad34bb","DOIUrl":"https://doi.org/10.1088/1674-4527/ad34bb","url":null,"abstract":"\u0000 Determining asteroid properties provides valuable physical insights but inverting them from photometric lightcurves remains computationally intensive. This paper presents a new approach that combines a simplified Cellinoid shape model with the Parallel Differential Evolution (PDE) algorithm to accelerate inversion. The PDE algorithm is more efficient than the Differential Evolution (DE) algorithm, achieving an extraordinary speedup of 37.983 with 64 workers on multicore CPUs. The PDE algorithm accurately derives period and pole values from simulated data. The analysis of real asteroid lightcurves validates the method's reliability: in comparison with results published elsewhere, the PDE algorithm accurately recovers the rotational periods and, given adequate viewing geometries, closely matches the pole orientations. The PDE approach converges to solutions within 20,000 iterations and under one hour, demonstrating its potential for large-scale data analysis. This work provides a promising new tool for unveiling asteroid physical properties by overcoming key computational bottlenecks.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"84 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140234970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Weak Merging scenario of the CLASH Cluster A209 CLASH星团A209的弱合并情景

Research in Astronomy and Astrophysics Pub Date : 2024-03-15 DOI: 10.1088/1674-4527/ad349a

Wencheng Feng, Heng Yu, Haihui Zhao, Xiaolan Hou, Shumei Jia, Chengkui Li, Yulin Cheng, Paolo Tozzi, Ming Sun, Yong chen

引用次数: 0

Prospects of the multi-channel photometric survey telescope in the cosmological application of Type Ia supernovae 多通道测光巡天望远镜在 Ia 型超新星宇宙学应用中的前景

Research in Astronomy and Astrophysics Pub Date : 2024-03-13 DOI: 10.1088/1674-4527/ad339f

Zhenyu Wang, Ju-Jia Zhang, X. Er, Jinming Bai

{"title":"Prospects of the multi-channel photometric survey telescope in the cosmological application of Type Ia supernovae","authors":"Zhenyu Wang, Ju-Jia Zhang, X. Er, Jinming Bai","doi":"10.1088/1674-4527/ad339f","DOIUrl":"https://doi.org/10.1088/1674-4527/ad339f","url":null,"abstract":"\u0000 The multi-channel photometric survey telescope (Mephisto) is a real-time, three-color photometric system designed to capture the color evolution of stars and transients accurately. This telescope system can be crucial in cosmological distance measurements of low-redshift (low-z, z $lesssim 0.1$) Type Ia supernovae (SNe Ia). To optimize the capabilities of this instrument, we performed a comprehensive simulation study before its official operation. By considering the impact of atmospheric extinction, weather conditions, and the lunar phase at the observing site involving the instrumental features, we simulated the light curve of SNe Ia obtained by the Mephisto. The best strategy in the case of SNe Ia cosmology is to take the image at an exposure time of 130 s with a cadence of 3 d. In this condition, Mephisto can obtain hundreds of high-quality SNe Ia to achieve a distance measurement better than $4.5%$. Given the on-time spectral classification and monitoring of the Lijiang 2.4m telescope at the same observatory, Mephisto, in the whole operation, can significantly enrich the well-calibrated sample of supernovae at low-z and improve the calibration accuracy of high-redshift (high-z) SNe Ia.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"2012 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140246367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Machine Learning-Based Identification of Contaminated Images in Light Curves Data Preprocessing 基于机器学习的光线曲线数据预处理中污染图像的识别

Research in Astronomy and Astrophysics Pub Date : 2024-03-13 DOI: 10.1088/1674-4527/ad339e

Hui Li, Rongwang Li, Peng Shu, Yuqiang Li

{"title":"Machine Learning-Based Identification of Contaminated Images in Light Curves Data Preprocessing","authors":"Hui Li, Rongwang Li, Peng Shu, Yuqiang Li","doi":"10.1088/1674-4527/ad339e","DOIUrl":"https://doi.org/10.1088/1674-4527/ad339e","url":null,"abstract":"\u0000 Attitude is one of the crucial parameters for space objects and plays a vital role in collision prediction and debris removal. Analyzing light curves to determine attitude is the most commonly used method. In photometric observations, outliers may exist in the obtained light curves due to various reasons. Therefore, preprocessing is required to remove these outliers to obtain high quality light curves. Through statistical analysis, the reasons leading to outliers can be categorized into two main types: first, the brightness of the object significantly increases due to the passage of a star nearby, referred to as \"stellar contamination,\" and second, the brightness markedly decreases due to cloudy cover, referred to as \"cloudy contamination.\" Traditional approach of manually inspecting images for contamination is time-consuming and labor-intensive. However, We propose the utilization of machine learning methods as a substitute. Convolutional Neural Networks (CNN) and Support Vector Machines (SVM) are employed to identify cases of stellar contamination and cloudy contamination, achieving accuracies of 100% and 97.12%, respectively. We also explored other machine learning methods such as Residual Network-18 (ResNet-18) and Light Gradient Boosting Machine (lightGBM), then conducted comparative analyses of the results.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140246189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Digitization of Astronomical Photographic Plate of China and Astrometric Measurement of Single-exposure Plates 中国天文照相底版数字化和单次曝光底版的天文测量

Research in Astronomy and Astrophysics Pub Date : 2024-03-13 DOI: 10.1088/1674-4527/ad339d

Z. Shang, Yong Yu, Liangliang Wang, Mei-Ting Yang, Jing Yang, Shiyin Shen, Min Liu, 权峰徐, Chenzhou Cui, Dongwei Fan, Zhenghong Tang, Jian-hai Zhao

{"title":"Digitization of Astronomical Photographic Plate of China and Astrometric Measurement of Single-exposure Plates","authors":"Z. Shang, Yong Yu, Liangliang Wang, Mei-Ting Yang, Jing Yang, Shiyin Shen, Min Liu, 权峰徐, Chenzhou Cui, Dongwei Fan, Zhenghong Tang, Jian-hai Zhao","doi":"10.1088/1674-4527/ad339d","DOIUrl":"https://doi.org/10.1088/1674-4527/ad339d","url":null,"abstract":"\u0000 From the mid-19th century to the end of the 20th century, photographic plates served as the primary detectors for astronomical observations. Astronomical photographic observations in China began in 1901, and over a century, a total of approximately 30,000 astronomical photographic plates have been captured. These historical plates play an irreplaceable role in conducting long-term, time-domain astronomical research. To preserve and explore these valuable original astronomical observational data, Shanghai Astronomical Observatory has organized the transportation of plates taken at night from various stations across the country to the Sheshan Plate Archive for centralized preservation. For the first time, plate information statistics was performed. On this basis, the plates were cleaned and digitally scanned, and finally digitized images were acquired for 29,314 plates. In this study, using Gaia DR2 as the reference star catalog, astrometric processing has been carried out successfully on 15,696 single-exposure plates, including object extraction, stellar identification, and plate model computation. As a result, for long focal length telescopes, such as the 40cm double-tube refractor telescope and the 1.56m reflector telescope at the Shanghai Astronomical Observatory and the 1m reflector telescope at the Yunnan Astronomical Observatory, the astrometric accuracy obtained for their plates is approximately 0.1′′ to 0.3′′. The distribution of astrometric accuracy for medium and short focal length telescopes ranges from 0.3′′ to 1.0′′. The relevant data of this batch of plates, including digitized images and stellar catalog of the plates are archived and released by the National Astronomical Data Center. Users can access and download plate data based on keywords such as station, telescope, observation year, and observed celestial coordinates.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"311 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140247106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0