Frontiers in Astronomy and Space Sciences最新文献_第8页

The temporal and latitudinal dependences of turbulence driven by pickup ions in the outer heliosphere 外日光层拾取离子驱动湍流的时间和纬度相关性

IF 3 3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-12-01 DOI: 10.3389/fspas.2023.1298577

Bingbing Wang, Lingling Zhao, Paria Abouhamzeh, G. Zank, L. Adhikari

{"title":"The temporal and latitudinal dependences of turbulence driven by pickup ions in the outer heliosphere","authors":"Bingbing Wang, Lingling Zhao, Paria Abouhamzeh, G. Zank, L. Adhikari","doi":"10.3389/fspas.2023.1298577","DOIUrl":"https://doi.org/10.3389/fspas.2023.1298577","url":null,"abstract":"The distribution of turbulence in the heliosphere remains a mystery, due to the complexity in not only modeling the turbulence transport equations but also identifying the drivers of turbulence that vary with time and spatial location. Beyond the ionization cavity (a few astronomical units (AU) from the Sun), the turbulence is driven predominantly by freshly created pickup ions (PUIs), in contrast to the driving by stream shear and compression. Understanding the source characteristics is necessary to refine turbulence transport models and interpret measurements of turbulence and solar wind temperature in the outer heliosphere. Using a recent latitude-dependent solar wind speed model and the ionization rate of neutral interstellar hydrogen (H), we investigate the temporal and spatial variation in the strength of low-frequency turbulence driven by PUIs from 1998 to 2020. We find that the driving rate is stronger during periods of high solar activity and at lower latitudes in the outer heliosphere. The driving rates for parallel and anti-parallel propagating (relative to the background magnetic field) slab turbulence have different spatial and latitude dependences. The calculated generation rate of turbulence by PUIs is an essential ingredient to investigate the latitude dependence of turbulence in the outer heliosphere, which is important to understand the heating of the distant solar wind and the modulation of cosmic rays.","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138618365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Nuclear data resources and initiatives for nuclear astrophysics 核天体物理学的核数据资源和倡议

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-10 DOI: 10.3389/fspas.2023.1243615

Michael S. Smith

{"title":"Nuclear data resources and initiatives for nuclear astrophysics","authors":"Michael S. Smith","doi":"10.3389/fspas.2023.1243615","DOIUrl":"https://doi.org/10.3389/fspas.2023.1243615","url":null,"abstract":"Research into the cosmic synthesis of the elements, the evolution and explosion of stars, the nature of the early Universe, and other important topics in nuclear astrophysics are at the forefront of nuclear science. These studies are motivating laboratory measurements and theoretical calculations that, after significant investments, are pushing the boundaries of what is possible. The latest nuclear results, however, must be specially prepared before they can be used to advance our knowledge of the cosmos. This processing requires a set of resources unique to nuclear astrophysics, and an impressive collection of nuclear reaction and nuclear structure datasets, processing codes, thermonuclear reaction rate libraries, and simulation codes and services have been developed for the field. There are, however, some serious challenges to these efforts that will only worsen in the future, making it important to develop strategies and act now to ensure a sustainable future for this work. After detailing the specific data types needed for nuclear astrophysics and the available data resources, the major challenges in this work and their implications are discussed. A set of initiatives are proposed to meet those challenges along with suggested implementations and possible ways that they may advance our understanding of the Universe and strengthen the field of nuclear astrophysics.","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135186400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Effects of the evolving early Moon and Earth magnetospheres 早期月球和地球磁层演化的影响

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-10 DOI: 10.3389/fspas.2023.1112233

James Green, Scott Boardsen, Chuanfei Dong

{"title":"Effects of the evolving early Moon and Earth magnetospheres","authors":"James Green, Scott Boardsen, Chuanfei Dong","doi":"10.3389/fspas.2023.1112233","DOIUrl":"https://doi.org/10.3389/fspas.2023.1112233","url":null,"abstract":"Recently it has been identified that our Moon had an extensive magnetosphere for several hundred million years soon after it was formed when the Moon was within 20 Earth Radii (R E ) from the Earth. Some aspects of the interaction between the early Earth-Moon magnetospheres are investigated by mapping the interconnected field lines between the Earth and the Moon and investigating how the early lunar magnetosphere affects the magnetospheric dynamics within the coupled magnetospheres over time. So long as the magnetosphere of the Moon remains strong as it moves away from the Earth in the antialigned dipole configuration, the extent of the Earth’s open field lines decreases. As a result, at times it significantly changes the structure of the field-aligned current system, pushing the polar cusp significantly northward, and forcing magnetotail reconnection sites into the deeper tail region. In addition, the combined magnetospheres of the Earth and the Moon greatly extend the number of closed field lines enabling a much larger plasmasphere to exist and connecting the lunar polar cap with closed field lines to the Earth. That configuration supports the transfer of plasma between the Earth and the Moon potentially creating a time capsule of the evolution of volatiles with depth. This paper only touches on the evolution of the early Earth and Moon magnetospheres, which has been a largely neglected space physics problem and has great potential for complex follow-on studies using more advanced tools and due to the expected new lunar data coming in the next decade through the Artemis Program.","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135186910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Dispersive propagation of nuclear electromagnetic pulse in the ionosphere 核电磁脉冲在电离层中的色散传播

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-09 DOI: 10.3389/fspas.2023.1201921

Yongli Wei, Dinghan Zhu, Zongxiang Li, Lihua Wang, Yuan Wang, Tianchi Zhang, Bin Xing, Baofeng Cao, Peng Li

{"title":"Dispersive propagation of nuclear electromagnetic pulse in the ionosphere","authors":"Yongli Wei, Dinghan Zhu, Zongxiang Li, Lihua Wang, Yuan Wang, Tianchi Zhang, Bin Xing, Baofeng Cao, Peng Li","doi":"10.3389/fspas.2023.1201921","DOIUrl":"https://doi.org/10.3389/fspas.2023.1201921","url":null,"abstract":"Introduction: On the propagation path to the satellite, the ionosphere will distort the nuclear electromagnetic pulse (NEMP) and change its physical properties. Methods: This paper proposes a method for calculating the propagation of NEMP to the satellite. The method decomposes NEMP into the superposition of simple harmonic waves, and each simple harmonic wave is calculated separately in the ionosphere. With the consideration of different time of arrival and critical frequency of the ionosphere, the NEMP after propagating in the ionosphere is obtained by superposition of simple harmonic waves in time domain rather than the inverse Fourier transform which will erase the time domain information. Results: The results show that NEMP is dispersive in ionosphere with the pulse broadened, the speeds changed and the bandwidth narrowed. The time-frequency spectrum can provide the frequency band where the signal energy is located. Discussion: Our proposed method provides a simple and effective way to calculate the NEMP propagation in the ionosphere, which should afford help to the design of NEMP receivers and the selection of satellite orbit altitude.","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135291808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

2a Results: galaxy to cloud scales 2a结果:星系到云的尺度

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-09 DOI: 10.3389/fspas.2023.1272771

Clare Dobbs

{"title":"2a Results: galaxy to cloud scales","authors":"Clare Dobbs","doi":"10.3389/fspas.2023.1272771","DOIUrl":"https://doi.org/10.3389/fspas.2023.1272771","url":null,"abstract":"Simulations from the scales of isolated galaxies to clouds have been instrumental in informing us about molecular cloud formation and evolution. Simulations are able to investigate the roles of gravity, feedback, turbulence, heating and cooling, and magnetic fields on the physics of the interstellar medium, and star formation. Compared to simulations of individual clouds, galactic and sub-galactic scale simulations can include larger galactic scale processes such as spiral arms, bars, and larger supernovae bubbles, which may influence star formation. Simulations show cloud properties and lifetimes in broad agreement with observations. Gravity and spiral arms are required to produce more massive GMCs, whilst stellar feedback, likely photoionisation, leads to relatively short cloud lifetimes. On larger scales, supernovae may be more dominant in driving the structure and dynamics, but photoionisation may still have a role. In terms of the dynamics, feedback is probably the main driver of velocity dispersions, but large scale processes such as gravity and spiral arms may also be significant. Magnetic fields are generally found to decrease star formation on galaxy or cloud scales, and simulations are ongoing to study whether clouds are sub or supercritical on different scales in galaxy scale simulations. Simulations on subgalactic scales, or zoom in simulations, allow better resolution of feedback processes, filamentary structure within clouds, and the study of stellar clusters.","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135292445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Study of the isomeric yield ratio in the photoneutron reaction of natural holmium induced by laser-accelerated electron beams 激光加速电子束诱导天然钬光-中子反应中异构体产率的研究

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-08 DOI: 10.3389/fspas.2023.1265919

Jingli Zhang, Wei Qi, Wenru Fan, Zongwei Cao, Kaijun Luo, Changxiang Tan, Xiaohui Zhang, Zhigang Deng, Zhimeng Zhang, Xinxiang Li, Yun Yuan, Wen Luo, Weimin Zhou

{"title":"Study of the isomeric yield ratio in the photoneutron reaction of natural holmium induced by laser-accelerated electron beams","authors":"Jingli Zhang, Wei Qi, Wenru Fan, Zongwei Cao, Kaijun Luo, Changxiang Tan, Xiaohui Zhang, Zhigang Deng, Zhimeng Zhang, Xinxiang Li, Yun Yuan, Wen Luo, Weimin Zhou","doi":"10.3389/fspas.2023.1265919","DOIUrl":"https://doi.org/10.3389/fspas.2023.1265919","url":null,"abstract":"Introduction: An accurate knowledge of the isomeric yield ratio (IR) induced by the photonuclear reaction is crucial to study the nuclear structure and reaction mechanisms. 165 Ho is a good candidate for the investigation of the IR since the Ho target has a natural abundance of 100% and the residual nuclide has a good decay property. Methods: In this study, the photoneutron production of 164m, g Ho induced by laser-accelerated electron beams is investigated experimentally. The γ-ray spectra of activated Ho foils are off-line detected. Since the direct transitions from the 164m Ho are not successfully observed, we propose to extract the IRs of the 164m, g Ho using only the photopeak counts from the ground-state decay. Results: The production yields of 164m, g Ho are extracted to be (0.45 ± 0.10) × 10 6 and (1.48 ± 0.14) × 10 6 per laser shot, respectively. The resulting IR is obtained to be 0.30 ± 0.08 at the effective γ-ray energy of 12.65 MeV. Discussion: The present data, available experimental data, and TALYS calculations are then compared to examine the role of the excitation energy. It is found that besides the giant dipole resonance, the excitation energy effect also plays a key role in the determination of the IRs.","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135393246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Thermal fluctuations, QNMs, and emission energy of charged ADS black hole with nonlinear electrodynamics 非线性电动力学下带电ADS黑洞的热涨落、QNMs和发射能量

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-07 DOI: 10.3389/fspas.2023.1174029

Faisal Javed, Abdul Basit, Aylin Caliskan, Ertan Güdekli

引用次数: 0

Statistical analysis of equatorial electrojet responses to the transient changes of solar wind conditions 赤道电喷流对太阳风瞬态变化响应的统计分析

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-07 DOI: 10.3389/fspas.2023.1306279

Jiawei Zhang, Qiaoling Li, Shuhan Li, Jing Liu

{"title":"Statistical analysis of equatorial electrojet responses to the transient changes of solar wind conditions","authors":"Jiawei Zhang, Qiaoling Li, Shuhan Li, Jing Liu","doi":"10.3389/fspas.2023.1306279","DOIUrl":"https://doi.org/10.3389/fspas.2023.1306279","url":null,"abstract":"Introduction: Prior case studies have indicated that changes in solar wind conditions have a significant impact on equatorial ionospheric electrodynamics. However, there have been limited statistical studies on this topic, impairing our understanding of the coupling between solar wind, magnetosphere, and equatorial ionosphere electrodynamics. Methods: In this study, we conducted a superposed epoch analysis of long-term data from the South America equatorial electrojet (EEJ) spanning from 2001 to 2021 examining the responses of the equatorial ionospheric electric field to step-like changes in solar wind velocity, density, dynamic pressure, and interplanetary magnetic field (IMF) B z . Result: Our study shows that step-like changes in solar wind velocity, density, and dynamic pressure can trigger changes in EEJ within ∼20–40 min. EEJ exhibits the highest sensitivity to variations in solar wind velocity while being relatively less sensitive to changes in dynamic pressure. Furthermore, the response of EEJ shows greater responsiveness to northward IMF B z compared to southward IMF B z . Discussion: Our work provides statistical evidence of how changes in solar wind can lead to changes in low-latitude ionospheric EEJ. We inferred that the changes in solar wind conditions cause magnetospheric deformation and changes in magnetic reconnection rates, leading to the fluctuations of the ionospheric electric field and the resultant EEJ variations.","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Electron cyclotron harmonic waves in Jovian magnetosphere as seen by Juno 朱诺号观测到的木星磁层中的电子回旋谐波

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-07 DOI: 10.3389/fspas.2023.1274760

J. Joseph, A. N. Jaynes, W. S. Kurth, J. D. Menietti, J. E. P. Connerney, S. J. Bolton

引用次数: 0

Corrigendum: Hydrogen atoms near the exobase are cold: independent observations do not support the hot exosphere concept 勘误:靠近外逸层的氢原子是冷的:独立观测不支持热的外逸层概念

3区物理与天体物理

Frontiers in Astronomy and Space Sciences Pub Date : 2023-11-07 DOI: 10.3389/fspas.2023.1320143

Dmytro Kotov, Oleksandr Bogomaz

{"title":"Corrigendum: Hydrogen atoms near the exobase are cold: independent observations do not support the hot exosphere concept","authors":"Dmytro Kotov, Oleksandr Bogomaz","doi":"10.3389/fspas.2023.1320143","DOIUrl":"https://doi.org/10.3389/fspas.2023.1320143","url":null,"abstract":"• please read through all the templates before choosing • pick the most relevant text template(s) from the following page and delete all others.• edit the text as necessary, ensuring that the original incorrect text is included for the record, please see the below. • please do not use any extra formatting when editing the templates, and only modify the red text unless absolutely necessary • submit to Frontiers following the instructions on this page.When the original text contained incorrect information, to preserve the scientific record, please include that text when editing the below templates. For example:There was a mistake in the Funding statement, an incorrect number was used. The correct number is \"2015C03Bd051.\". The publisher apologizes for this mistake.The original version of this article has been updated. In the published article, there was an error. [In the published article, there was a typo in the Text. The word \"hot\" was used incorrectly instead of a proper word \"cold\" as shown below. Despite the rest of phrase after the word indicate for the readers that the \"hot\" is incorrect, this typo may certainly confuse the readers].","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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