Research in Astronomy and Astrophysics最新文献_第6页

Reflector Deformation Measurement and Correction Methodology of Large Antenna Based on Phased Array Feed 基于相控阵馈线的大型天线反射器变形测量与修正方法

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-03-19 DOI: 10.1088/1674-4527/ad2ac2

Zan Wang, De-Qing Kong, Hong-Bo Zhang, Yan Su, Xin-Ying Zhu, Cong-Si Wang, Yu-Chen Liu

引用次数: 0

Quantifying the Tension between Cosmological Models and JWST Red Candidate Massive Galaxies 量化宇宙学模型与 JWST 红色候选大质量星系之间的张力

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-03-19 DOI: 10.1088/1674-4527/ad2cd3

Jun-Chao Wang, Zhi-Qi Huang, Lu Huang, Jianqi Liu

引用次数: 0

Cosmological Constraints on Neutrino Masses in Light of JWST Red and Massive Candidate Galaxies 从 JWST 红色和大质量候选星系看中微子质量的宇宙学约束

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-03-18 DOI: 10.1088/1674-4527/ad2c3f

Jian-Qi Liu, Zhi-Qi Huang, Yan Su

{"title":"Cosmological Constraints on Neutrino Masses in Light of JWST Red and Massive Candidate Galaxies","authors":"Jian-Qi Liu, Zhi-Qi Huang, Yan Su","doi":"10.1088/1674-4527/ad2c3f","DOIUrl":"https://doi.org/10.1088/1674-4527/ad2c3f","url":null,"abstract":"The overabundance of the red and massive candidate galaxies observed by the James Webb Space Telescope (JWST) implies efficient structure formation or large star formation efficiency at high redshift <italic toggle=\"yes\">z</italic> ∼ 10. In the scenario of a low or moderate star formation efficiency, because massive neutrinos tend to suppress the growth of structure of the universe, the JWST observation tightens the upper bound of the neutrino masses. Assuming Λ cold dark matter cosmology and a star formation efficiency ∈[0.05, 0.3] (flat prior), we perform joint analyses of Planck+JWST and Planck+BAO+JWST, and obtain improved constraints ∑<italic toggle=\"yes\">m</italic>\u0000\u0000<italic toggle=\"yes\">ν</italic>\u0000 < 0.196 eV and ∑<italic toggle=\"yes\">m</italic>\u0000\u0000<italic toggle=\"yes\">ν</italic>\u0000 < 0.111 eV at 95% confidence level, respectively. Based on the above assumptions, the inverted mass ordering, which implies ∑<italic toggle=\"yes\">m</italic>\u0000\u0000<italic toggle=\"yes\">ν</italic>\u0000 ≥ 0.1eV, is excluded by Planck+BAO+JWST at 92.7% confidence level.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"33 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314408","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

EP Aquarii: A New Picture of the Circumstellar Envelope 水瓶座 EP：恒星环包的新图景

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-03-05 DOI: 10.1088/1674-4527/ad18a4

Pham T. Nhung, Do T. Hoai, Pierre Darriulat, Pham Tuan-Anh, Pham N. Diep, Nguyen B. Ngoc, Tran T. Thai

{"title":"EP Aquarii: A New Picture of the Circumstellar Envelope","authors":"Pham T. Nhung, Do T. Hoai, Pierre Darriulat, Pham Tuan-Anh, Pham N. Diep, Nguyen B. Ngoc, Tran T. Thai","doi":"10.1088/1674-4527/ad18a4","DOIUrl":"https://doi.org/10.1088/1674-4527/ad18a4","url":null,"abstract":"New analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented, which complete a previously published analysis and offer a different interpretation of the morpho-kinematics of the circumstellar envelope. The birth of the equatorial density enhancement (EDE) is shown to occur very close to the star where evidence for rotation has been obtained. Close to the star and where outflows have been observed: their interaction with the gas of the nascent EDE is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8 to 10 km s−1 on the polar symmetry axis to ∼2 km s−1 at the equator. It implies complex morpho-kinematics: making reliable interpretations with reasonable confidence is difficult. In particular, it questions an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of ∼0.″4 from its center. It proposes instead an interpretation in terms of a standard mass ejection associated with a shock wave leaving a void of emission in its wake. High Doppler velocity wings are seen to consist of two components, the upper velocity end of the global wind, reaching above ±12 km s−1, and an effective line broadening, confined within 200 mas from the center of the star, reaching above ±20 km s−1 and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell partition.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"33 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314129","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

Gamma/Hadron Separation Method for the HADAR Experiment 用于 HADAR 实验的伽马/哈德龙分离方法

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-02-20 DOI: 10.1088/1674-4527/ad23cc

Yang-Zhao Ren, Tian-Lu Chen, You-Liang Feng, Dan-Zeng Luo-Bu, Yi-Qing Guo, Cheng Liu, Qi Gao, Mao-Yuan Liu, Xiang-Li Qian, Ya-Ping Wang, Zi-Hao Zhang, Xin-Long Li, Qing-Yuan Hou, Heng-Jiao Liu, Qing-Qian Zhou, Shan-Jie Shu

{"title":"Gamma/Hadron Separation Method for the HADAR Experiment","authors":"Yang-Zhao Ren, Tian-Lu Chen, You-Liang Feng, Dan-Zeng Luo-Bu, Yi-Qing Guo, Cheng Liu, Qi Gao, Mao-Yuan Liu, Xiang-Li Qian, Ya-Ping Wang, Zi-Hao Zhang, Xin-Long Li, Qing-Yuan Hou, Heng-Jiao Liu, Qing-Qian Zhou, Shan-Jie Shu","doi":"10.1088/1674-4527/ad23cc","DOIUrl":"https://doi.org/10.1088/1674-4527/ad23cc","url":null,"abstract":"Ground-based arrays of imaging atmospheric Cherenkov telescopes (IACTs) are the most sensitive <italic toggle=\"yes\">γ</italic>-ray detectors for energies of approximately 100 GeV and above. One such IACT is the High Altitude Detection of Astronomical Radiation (HADAR) experiment, which uses a large aperture refractive water lens system to capture atmospheric Cherenkov photons (i.e., the imaging atmospheric Cherenkov technique). The telescope array has a low threshold energy and large field of view, and can continuously scan the area of the sky being observed, which is conducive to monitoring and promptly responding to transient phenomena. The process of <italic toggle=\"yes\">γ</italic>-hadron separation is essential in very-high-energy (>30 GeV) <italic toggle=\"yes\">γ</italic>-ray astronomy and is a key factor for the successful utilization of IACTs. In this study, Monte Carlo simulations were carried out to model the response of cosmic rays within the HADAR detectors. By analyzing the Hillas parameters and the distance between the event core and the telescope, the distinction between air showers initiated by <italic toggle=\"yes\">γ</italic>-rays and those initiated by cosmic rays was determined. Additionally, a Quality Factor was introduced to assess the telescope’s ability to suppress the background and to provide a more effective characterization of its performance.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"12 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140003876","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

Investigating the Evolution of Amati Parameters with Redshift 利用红移研究阿马蒂参数的演变

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2024-01-09 DOI: 10.1088/1674-4527/ad0fd5

Meghendra Singh, Darshan Singh, Kanhaiya Lal Pandey, Dinkar Verma, Shashikant Gupta

{"title":"Investigating the Evolution of Amati Parameters with Redshift","authors":"Meghendra Singh, Darshan Singh, Kanhaiya Lal Pandey, Dinkar Verma, Shashikant Gupta","doi":"10.1088/1674-4527/ad0fd5","DOIUrl":"https://doi.org/10.1088/1674-4527/ad0fd5","url":null,"abstract":"Gamma-ray bursts (GRBs) are among the brightest objects in the Universe and, hence, can be observed up to a very high redshift. Properly calibrated empirical correlations between intensity and spectral correlations of GRBs can be used to estimate the cosmological parameters. However, the possibility of the evolution of GRBs with redshift is a long-standing puzzle. In this work, we used 162 long-duration GRBs to determine whether GRBs below and above a certain redshift have different properties. The GRBs are split into two groups, and we fit the Amati relation for each group separately. Our findings demonstrate that estimations of the Amati parameters for the two groups are substantially dissimilar. We perform simulations to investigate whether the selection effects could cause the difference. Our analysis shows that the differences may be either intrinsic or due to systematic errors in the data, and the selection effects are not their true origin. However, in-depth analysis with a new data set comprised of 119 long GRBs shows that intrinsic scatter may partly be responsible for such effects.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"30 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139507345","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 impact of bias row noise to photometric accuracy: case study based on a scientific CMOS detector 偏置行噪声对测光精度的影响：基于科学 CMOS 探测器的案例研究

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2023-12-20 DOI: 10.1088/1674-4527/ad1793

Li Shao, Hu Zhan, Chao Liu, Haonan Chi, Qiuyan Luo, Huaipu Mu, Wenzhong Shi

引用次数: 0

Data-driven simulations of magnetic field evolution in Active Region 11429: Magneto-friction method using PENCIL code 数据驱动的 11429 活动区磁场演变模拟：使用 PENCIL 代码的磁摩擦方法

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2023-12-19 DOI: 10.1088/1674-4527/ad16fb

P. Vemareddy, Jorn Warnecke, P.A. Bourdin

{"title":"Data-driven simulations of magnetic field evolution in Active Region 11429: Magneto-friction method using PENCIL code","authors":"P. Vemareddy, Jorn Warnecke, P.A. Bourdin","doi":"10.1088/1674-4527/ad16fb","DOIUrl":"https://doi.org/10.1088/1674-4527/ad16fb","url":null,"abstract":"\u0000 Coronal magnetic fields evolve quasi statically over long time scales and dynamically over short time scales. As of now there exists no regular measurements of coronal magnetic fields, and therefore generating the coronal magnetic field evolution using the observations of the magnetic field at the photosphere is of fundamental requirement to understand the origin of the transient phenomena from the solar active regions. Using the magnetofriction (MF) approach, we aim to simulate the coronal field evolution in the solar active region 11429. The MF method is implemented in open source PC along with a driver module to drive the initial field with different boundary conditions prescribed from observed vector magnetic fields at the photosphere. In order to work with vector potential and the observations, we prescribe three types of bottom boundary drivers with varying free-magnetic energy. The MF simulation reproduces the magnetic structure which better matches to the sigmoidal morphology exhibited by AIA images at the pre-eruptive time. We found that the already sheared field further driven by the sheared magnetic field will maintain and further build the highly sheared coronal magnetic configuration such as seen in AR 11429. Data-driven MF simulation is a viable tool to generate the coronal magnetic field evolution capturing the formation of the twisted flux rope and its eruption.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":" 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138959881","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

Point-symmetry in SNR G1.9+0.3: A Supernova that Destroyed its Planetary Nebula Progenitor SNR G1.9+0.3中的点对称性：摧毁其行星状星云原生体的超新星

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2023-12-19 DOI: 10.1088/1674-4527/ad0ded

Noam Soker

引用次数: 0

Research on Pulsar Time Steered Atomic Time Algorithm Based on DPLL 基于 DPLL 的脉冲星时间引导原子时算法研究

IF 1.8 4区物理与天体物理

Research in Astronomy and Astrophysics Pub Date : 2023-12-16 DOI: 10.1088/1674-4527/ad1659

Zehao Zheng, Yang Liu, D. Shen, Fan Feng, Jiulong Liu, Yuexin Ma, Xiangwei Zhu

{"title":"Research on Pulsar Time Steered Atomic Time Algorithm Based on DPLL","authors":"Zehao Zheng, Yang Liu, D. Shen, Fan Feng, Jiulong Liu, Yuexin Ma, Xiangwei Zhu","doi":"10.1088/1674-4527/ad1659","DOIUrl":"https://doi.org/10.1088/1674-4527/ad1659","url":null,"abstract":"\u0000 In today's society, there is a wide demand for high-precision and high-stability time service in the fields of electric power, communication, transportation and finance. At present, the time standard in various countries is mainly based on atomic clocks, but the frequency drift of atomic clocks will affect the long-term stability performance. Compared with atomic clocks, millisecond pulsars have better long-term stability and can complement with the excellent short-term stability of atomic clocks. In order to improve the long-term stability of the atomic time scale, and then improve the timing accuracy, this paper proposes an algorithm for steering the Atomic clock ensemble (ACE) by Ensemble pulsar time (EPT) based on Digital phase locked loop (DPLL). Firstly, the ACE and EPT are generated by ALGOS algorithm, then the ACE is steered by EPT based on DPLL to calibrate the long-term frequency drift of the atomic clock, so that the generated steered atomic time follows both the short-term stability characteristics of ACE and the long-term stability characteristics of EPT, and finally, the steered atomic time is used to calibrate the local cesium clock. The experimental results show that the long-term stability of atomic time after steering is improved by 2 orders of magnitude compared with that before steering, and the daily drift of local cesium clock after calibration is less than 9.47ns in 3 years, 3 orders of magnitude higher than that before calibration on accuracy.","PeriodicalId":54494,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"50 8","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995830","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