Pub Date : 2024-05-09DOI: 10.3389/fspas.2024.1371787
Eduard Fernando Piratova-Moreno, Luz Ángela García
This theoretical work investigates different models to predict the redshift of fast radio bursts (FRBs) from their observed dispersion measure (DM) and other reported properties. We performed an extended revision of the FRBs with confirmed galaxy hosts in the literature and built the most updated catalog to date. With this sample of FRBs, we propose four models that relate the DM and z: a linear trend (inspired by the Macquart relation), a log-parabolic function, a power law, and an interpolation for DM that includes z and the position of the host galaxy of the transient. The latter model has the highest success rate according to the metrics implemented: likelihood, median of the z difference, and the Akaike and Bayesian information criteria. Although the performance of model D is closely followed by the power law and linear models, the former has the advantage of accounting for anisotropies in the dispersion measure due to the angular coordinates. Conversely, the log-parabolic formula performs poorly in this task but provides a good prediction for FRBs with low DM at a low redshift. Additionally, we use the reported galaxy properties of the hosts to establish a connection between the observed DM with the star formation rate (SFR) and stellar mass (Ms) of the galaxies where the FRBs reside. In both cases, we find a weak correlation. Although the studied correlations are well-motivated, the sample of FRBs is not statistically significant enough to draw solid conclusions in this second part of our work. With the advent of new facilities devoted to studying the localization and nature of these transients, we will get access to new data that will enrich the proposed models and give us hints on the astrophysical origin and evolution of FRBs.
这项理论工作研究了不同的模型，以便根据观测到的频散测量（DM）和其他报告的特性来预测快速射电暴（FRBs）的红移。我们对文献中已确认星系宿主的快速射电暴进行了扩展修订，并建立了迄今为止最新的星表。根据这个FRB样本，我们提出了四种DM和z相关的模型：线性趋势（受Macquart关系的启发）、对数抛物线函数、幂律以及包含z和瞬变宿主星系位置的DM内插法。根据所采用的指标：似然比、z 差值中位数、阿凯克和贝叶斯信息标准，后一种模型的成功率最高。虽然模型 D 的性能紧随幂律模型和线性模型之后，但前者的优势是可以考虑角坐标引起的色散测量中的各向异性。相反，对数抛物线公式在这项任务中的表现较差，但却能很好地预测低红移时低DM的FRB。此外，我们还利用报告的宿主星系特性，建立了观测到的DM与FRB所在星系的恒星形成率（SFR）和恒星质量（Ms）之间的联系。在这两种情况下，我们都发现了微弱的相关性。尽管所研究的相关性有很好的动机，但FRB的样本在统计上并不显著，不足以在我们的第二部分工作中得出可靠的结论。随着专门研究这些瞬变的定位和性质的新设施的出现，我们将获得新的数据，这些数据将丰富所提出的模型，并为我们提供有关 FRB 的天体物理起源和演化的提示。
{"title":"Modeling the dispersion measure—redshift relation for fast radio bursts","authors":"Eduard Fernando Piratova-Moreno, Luz Ángela García","doi":"10.3389/fspas.2024.1371787","DOIUrl":"https://doi.org/10.3389/fspas.2024.1371787","url":null,"abstract":"This theoretical work investigates different models to predict the redshift of fast radio bursts (FRBs) from their observed dispersion measure (DM) and other reported properties. We performed an extended revision of the FRBs with confirmed galaxy hosts in the literature and built the most updated catalog to date. With this sample of FRBs, we propose four models that relate the DM and z: a linear trend (inspired by the Macquart relation), a log-parabolic function, a power law, and an interpolation for DM that includes z and the position of the host galaxy of the transient. The latter model has the highest success rate according to the metrics implemented: likelihood, median of the z difference, and the Akaike and Bayesian information criteria. Although the performance of model D is closely followed by the power law and linear models, the former has the advantage of accounting for anisotropies in the dispersion measure due to the angular coordinates. Conversely, the log-parabolic formula performs poorly in this task but provides a good prediction for FRBs with low DM at a low redshift. Additionally, we use the reported galaxy properties of the hosts to establish a connection between the observed DM with the star formation rate (SFR) and stellar mass (Ms) of the galaxies where the FRBs reside. In both cases, we find a weak correlation. Although the studied correlations are well-motivated, the sample of FRBs is not statistically significant enough to draw solid conclusions in this second part of our work. With the advent of new facilities devoted to studying the localization and nature of these transients, we will get access to new data that will enrich the proposed models and give us hints on the astrophysical origin and evolution of FRBs.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":" 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140995966","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}
Pub Date : 2024-05-09DOI: 10.3389/fspas.2024.1395775
L. Biasiotti, S. Ivanovski, Lorenzo Calderone, Giovanna Jerse, M. Laurenza, Dario Del Moro, Francesco Longo, C. Plainaki, M. F. Marcucci, A. Milillo, Marco Molinaro, Chiara Feruglio
Introduction: Kelvin-Helmholtz (KH) and tearing mode (TM) instabilities are one of the most important mechanisms of solar wind energy, momentum and plasma transport within the magnetosphere.Methods: To investigate the conditions under which KHTM instabilities occur in the Earth environment it is fundamental to combine simultaneous multipoint in situ measurements and MHD simulations. We analyzed data from the THEMIS and Cluster spacecraft considering two Space Weather (SWE) events starting with an M2.0 flare event (hereafter Case-1) that occurred on 21 June 2015 and the most-intensive flare (X9.3) of solar cycle 24 that occurred on 6 September 2017 (hereafter Case-2).Results: Our analysis utilized a 2D MHD model for incompressible and viscous flow. The results from Case-1 indicate the presence of KH and TM instabilities, suggesting existence of observed low-amplitude oscillations at the nose of the magnetopause. However, the MHD simulations for Case-2 did not show any evidence of KH vortices, but did reveal the presence of “magnetic island” structures during a low-shear condition. The reconnection rate derived from the observations is compared with the computed one in the presence of developed instabilities inside the Earth’s magnetopause.
{"title":"Evidence of Kelvin-Helmholtz and tearing mode instabilities at the magnetopause during space weather events","authors":"L. Biasiotti, S. Ivanovski, Lorenzo Calderone, Giovanna Jerse, M. Laurenza, Dario Del Moro, Francesco Longo, C. Plainaki, M. F. Marcucci, A. Milillo, Marco Molinaro, Chiara Feruglio","doi":"10.3389/fspas.2024.1395775","DOIUrl":"https://doi.org/10.3389/fspas.2024.1395775","url":null,"abstract":"Introduction: Kelvin-Helmholtz (KH) and tearing mode (TM) instabilities are one of the most important mechanisms of solar wind energy, momentum and plasma transport within the magnetosphere.Methods: To investigate the conditions under which KHTM instabilities occur in the Earth environment it is fundamental to combine simultaneous multipoint in situ measurements and MHD simulations. We analyzed data from the THEMIS and Cluster spacecraft considering two Space Weather (SWE) events starting with an M2.0 flare event (hereafter Case-1) that occurred on 21 June 2015 and the most-intensive flare (X9.3) of solar cycle 24 that occurred on 6 September 2017 (hereafter Case-2).Results: Our analysis utilized a 2D MHD model for incompressible and viscous flow. The results from Case-1 indicate the presence of KH and TM instabilities, suggesting existence of observed low-amplitude oscillations at the nose of the magnetopause. However, the MHD simulations for Case-2 did not show any evidence of KH vortices, but did reveal the presence of “magnetic island” structures during a low-shear condition. The reconnection rate derived from the observations is compared with the computed one in the presence of developed instabilities inside the Earth’s magnetopause.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":" 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140994309","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}
Pub Date : 2024-05-09DOI: 10.3389/fspas.2024.1396326
Mykola Shevchuk, V. Melnik, Anatolii Brazhenko, V. Dorovskyy, Anatolii Frantsuzenko, S. Poedts, J. Magdalenić
An analysis of the observational polarization properties of the decameter spikes is presented in the paper. It is shown that decameter spikes possess high degree of circular polarization with average value of about 60%. In the frames of “leading spot” theory we associated the spikes activity with a certain active region on the solar disk and determined the mode of the emission. Supposing plasma emission mechanism we link and determine coronal plasma and fast electron beam parameters.
{"title":"Polarization properties of the decameter spikes","authors":"Mykola Shevchuk, V. Melnik, Anatolii Brazhenko, V. Dorovskyy, Anatolii Frantsuzenko, S. Poedts, J. Magdalenić","doi":"10.3389/fspas.2024.1396326","DOIUrl":"https://doi.org/10.3389/fspas.2024.1396326","url":null,"abstract":"An analysis of the observational polarization properties of the decameter spikes is presented in the paper. It is shown that decameter spikes possess high degree of circular polarization with average value of about 60%. In the frames of “leading spot” theory we associated the spikes activity with a certain active region on the solar disk and determined the mode of the emission. Supposing plasma emission mechanism we link and determine coronal plasma and fast electron beam parameters.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":" 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140997246","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}
Pub Date : 2024-05-06DOI: 10.3389/fspas.2024.1402793
Yuanyu Hong, Chao Yang, Miaomiao Zhang, Yanpeng Chen, Binyang Liu
Introduction: In recent decades, numerous large survey projects have been initiated to enhance our understanding of the cosmos. Among these, the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) stands out as a flagship project of the Stage IV cosmology imaging surveys, offering an open-source framework for data management and processing adaptable to various instruments.Methods: In this paper, we introduce the ‘obs_mccd’ software package, designed to serve as a bridge linking raw data from generic mosaic-CCD instruments to the LSST data management framework. The package also facilitates the deployment of tailored configurations to the pipeline middleware. To validate our data processing pipeline, we processed a batch of realistic data from a commissioning wide-field telescope.Results: We established a prototype of the quality control (QC) system capable of assessing image quality parameters such as PSF size, ellipticity, and astrometric calibration. Our findings indicate that using a fifth-order polynomial for astrometric calibration effectively characterizes geometric distortion, achieving a median average geometric distortion residual of 0.011 pixel.Discussion: When comparing the performance of our pipeline to our in-house pipeline applied to the same dataset, we observed that our new ‘obs_mccd’ pipeline offers improved precision, reducing the median average geometric distortion residual from 0.016 pixel to 0.011 pixel. This enhancement in performance underscores the benefits of the obs_mccd package in managing and processing data from wide-field surveys, and it opens up new avenues for scientific exploration with smaller, flexible survey systems complementing the LSST.
{"title":"Optimizing image processing for modern wide field surveys: enhanced data management based on the LSST science pipelines","authors":"Yuanyu Hong, Chao Yang, Miaomiao Zhang, Yanpeng Chen, Binyang Liu","doi":"10.3389/fspas.2024.1402793","DOIUrl":"https://doi.org/10.3389/fspas.2024.1402793","url":null,"abstract":"Introduction: In recent decades, numerous large survey projects have been initiated to enhance our understanding of the cosmos. Among these, the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) stands out as a flagship project of the Stage IV cosmology imaging surveys, offering an open-source framework for data management and processing adaptable to various instruments.Methods: In this paper, we introduce the ‘obs_mccd’ software package, designed to serve as a bridge linking raw data from generic mosaic-CCD instruments to the LSST data management framework. The package also facilitates the deployment of tailored configurations to the pipeline middleware. To validate our data processing pipeline, we processed a batch of realistic data from a commissioning wide-field telescope.Results: We established a prototype of the quality control (QC) system capable of assessing image quality parameters such as PSF size, ellipticity, and astrometric calibration. Our findings indicate that using a fifth-order polynomial for astrometric calibration effectively characterizes geometric distortion, achieving a median average geometric distortion residual of 0.011 pixel.Discussion: When comparing the performance of our pipeline to our in-house pipeline applied to the same dataset, we observed that our new ‘obs_mccd’ pipeline offers improved precision, reducing the median average geometric distortion residual from 0.016 pixel to 0.011 pixel. This enhancement in performance underscores the benefits of the obs_mccd package in managing and processing data from wide-field surveys, and it opens up new avenues for scientific exploration with smaller, flexible survey systems complementing the LSST.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":"357 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141006800","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}
Pub Date : 2024-05-06DOI: 10.3389/fspas.2024.1381764
Jing Run Chen, Chaoling Tang, Xinxin Chu
Ultrarelativistic electrons (Ek > 3 MeV) are the most energetic electrons in the Earth’s outer radiation belt, which can cause serious damage to equipments on satellites. The evolutions of ultrarelativistic electrons during geomagnetic storm have been well understood, but the effects of continuous geomagnetic storm on ultrarelativistic electrons are still unclear. Using the data of the Van Allen Probes, we study the evolutions of ultrarelativistic electrons in the Earth’s outer radiation belt during the three continuous geomagnetic storm events. These continuous geomagnetic storm events include the two geomagnetic storms. During the recovery phase of the first geomagnetic storm, enhanced relativistic and ultrarelativistic electrons with lower energies (≥ 3.4 MeV) are observed. These enhanced relativistic electrons could be the source of ultrarelativistic electrons and contribute to ultrarelativistic electron acceleration during the second geomagnetic storm. While 3.4 MeV electrons could be further enhanced during the second geomagnetic storm. During the recovery phase of the second small or moderate geomagnetic storm, ultrarelativistic electrons with higher cutoff energies (≥ 5.2 MeV) and higher fluxes are observed. Compared to an isolated geomagnetic storm with similar solar wind and geomagnetic conditions, ultrarelativistic electrons with higher cutoff energies and higher fluxes are observed during the recovery phase of the second geomagnetic storm. We also find that continuous geomagnetic storm events may contribute even more to enhancements of ultrarelativistic electrons in the outer radiation belt if the second geomagnetic storm is a small or moderate storm with a low solar wind dynamic pressure and short-duration main phase. These can help us to further understand the evolutions of ultrarelativistic electrons in the Earth’s outer radiation belt during geomagnetic storms.
{"title":"The effect of continuous geomagnetic storms on enhancements of ultrarelativistic electrons in the Earth’s outer radiation belt","authors":"Jing Run Chen, Chaoling Tang, Xinxin Chu","doi":"10.3389/fspas.2024.1381764","DOIUrl":"https://doi.org/10.3389/fspas.2024.1381764","url":null,"abstract":"Ultrarelativistic electrons (Ek > 3 MeV) are the most energetic electrons in the Earth’s outer radiation belt, which can cause serious damage to equipments on satellites. The evolutions of ultrarelativistic electrons during geomagnetic storm have been well understood, but the effects of continuous geomagnetic storm on ultrarelativistic electrons are still unclear. Using the data of the Van Allen Probes, we study the evolutions of ultrarelativistic electrons in the Earth’s outer radiation belt during the three continuous geomagnetic storm events. These continuous geomagnetic storm events include the two geomagnetic storms. During the recovery phase of the first geomagnetic storm, enhanced relativistic and ultrarelativistic electrons with lower energies (≥ 3.4 MeV) are observed. These enhanced relativistic electrons could be the source of ultrarelativistic electrons and contribute to ultrarelativistic electron acceleration during the second geomagnetic storm. While 3.4 MeV electrons could be further enhanced during the second geomagnetic storm. During the recovery phase of the second small or moderate geomagnetic storm, ultrarelativistic electrons with higher cutoff energies (≥ 5.2 MeV) and higher fluxes are observed. Compared to an isolated geomagnetic storm with similar solar wind and geomagnetic conditions, ultrarelativistic electrons with higher cutoff energies and higher fluxes are observed during the recovery phase of the second geomagnetic storm. We also find that continuous geomagnetic storm events may contribute even more to enhancements of ultrarelativistic electrons in the outer radiation belt if the second geomagnetic storm is a small or moderate storm with a low solar wind dynamic pressure and short-duration main phase. These can help us to further understand the evolutions of ultrarelativistic electrons in the Earth’s outer radiation belt during geomagnetic storms.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":"57 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141007575","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}
Pub Date : 2024-05-06DOI: 10.3389/fspas.2024.1347048
Mohamad E. Abdelaal, Igor. V. Dokuchaev, Elena A. Malinovskaya, Stanislav I. Klimov, Genady G. Dolnikov, Alexander V. Zakharov
The upper atmosphere, comprising the mesosphere and thermosphere, is intricately influenced by various atmospheric and magnetospheric impacts. Various atmospheric waves excited in the troposphere can propagate into the mesosphere-thermosphere (M-T) region, altering its dynamics. Additionally, large-scale disturbances in the middle atmosphere, such as sudden stratospheric warming and geomagnetic disturbances induced by solar activity, affect the upper atmosphere. To better understand these complex processes, observations from multiple platforms and instruments, along with modeling studies, are necessary. This study presents experimental investigations into the electromagnetic signatures generated by atmospheric discharge conditions, including breakdown events and interactions of charged dust particles. A vacuum chamber was used to simulate upper atmospheric conditions. An electromagnetic signal analyzer (EMA) registered signals generated from the atmospheric discharge and the electromagnetic signature of charged dust particles. The results of the experimental investigations revealed distinctive electromagnetic processes occurring during breakdown events and charged particle interactions within Earth’s atmosphere. Signals recorded by the electromagnetic signal analyzer provided valuable insights into the characteristics of atmospheric discharge conditions and the behavior of charged dust particles. The findings contribute to our understanding of the complex interactions in the upper atmosphere. Further analysis of the results highlights the significance of the atmospheric discharge, electromagnetic processes, and dust particle interactions in shaping the dynamics of this region. The experimental approach presented in this study offers a valuable tool for studying atmospheric processes and their implications for space weather dynamics.
{"title":"Experimental modeling of atmospheric discharge phenomena and charged dust particle interactions","authors":"Mohamad E. Abdelaal, Igor. V. Dokuchaev, Elena A. Malinovskaya, Stanislav I. Klimov, Genady G. Dolnikov, Alexander V. Zakharov","doi":"10.3389/fspas.2024.1347048","DOIUrl":"https://doi.org/10.3389/fspas.2024.1347048","url":null,"abstract":"The upper atmosphere, comprising the mesosphere and thermosphere, is intricately influenced by various atmospheric and magnetospheric impacts. Various atmospheric waves excited in the troposphere can propagate into the mesosphere-thermosphere (M-T) region, altering its dynamics. Additionally, large-scale disturbances in the middle atmosphere, such as sudden stratospheric warming and geomagnetic disturbances induced by solar activity, affect the upper atmosphere. To better understand these complex processes, observations from multiple platforms and instruments, along with modeling studies, are necessary. This study presents experimental investigations into the electromagnetic signatures generated by atmospheric discharge conditions, including breakdown events and interactions of charged dust particles. A vacuum chamber was used to simulate upper atmospheric conditions. An electromagnetic signal analyzer (EMA) registered signals generated from the atmospheric discharge and the electromagnetic signature of charged dust particles. The results of the experimental investigations revealed distinctive electromagnetic processes occurring during breakdown events and charged particle interactions within Earth’s atmosphere. Signals recorded by the electromagnetic signal analyzer provided valuable insights into the characteristics of atmospheric discharge conditions and the behavior of charged dust particles. The findings contribute to our understanding of the complex interactions in the upper atmosphere. Further analysis of the results highlights the significance of the atmospheric discharge, electromagnetic processes, and dust particle interactions in shaping the dynamics of this region. The experimental approach presented in this study offers a valuable tool for studying atmospheric processes and their implications for space weather dynamics.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":"10 5‐6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141007150","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}
Pub Date : 2024-05-06DOI: 10.3389/fspas.2024.1379321
G. Cucho-Padin, Hyunju Connor, Jaewoong Jung, Michael Shoemaker, Kyle Murphy, D. Sibeck, Johannes Norberg, Enrique Rojas
Upcoming heliophysics missions utilize state-of-the-art wide field-of-view (FOV) imaging technology to measure and investigate the space plasma environment on a global scale. At Earth, remote sensing of soft X-ray emissions, which are generated via the charge exchange interaction between heavy solar wind ions and exospheric neutral atoms, is a promising means to investigate the global magnetosheath structure, its response to varying solar wind conditions, and the spatiotemporal properties of the dayside magnetic reconnection. Data analysis techniques such as optical tomography can provide additional structural and time-varying information from the observed target and thus enhance the mission’s scientific return. In this work, we simulate multiple and simultaneous observations of the dayside magnetosphere using soft X-ray imagers located at long-distance vantage points to reconstruct the time-dependent, three-dimensional (3-D) structure of the magnetosheath using a dynamic tomographic approach. The OpenGCCM MHD model is used to simulate the time-varying response of the magnetosheath to solar wind conditions and, subsequently, generate synthetic soft X-ray images from multiple spacecraft vantage points separated along a common orbit. A detailed analysis is then performed to identify the nominal set of spacecraft that produces the highest fidelity tomographic reconstruction of the magnetopause. This work aims to (i) demonstrate, for the first time, the use of dynamic tomography to retrieve the time-varying magnetosheath structure and (ii) identify a nominal mission design for multi-spacecraft configurations aiming for optical tomography.
即将进行的太阳物理学飞行任务利用最先进的宽视场（FOV）成像技术来测量和研究全球范围的空间等离子体环境。在地球上，通过重太阳风离子和外大气层中性原子之间的电荷交换相互作用产生的软 X 射线辐射遥感是研究全球磁鞘结构、其对太阳风条件变化的反应以及日侧磁重联的时空特性的一种很有前途的手段。光学层析成像等数据分析技术可以提供观测目标的额外结构和时变信息，从而提高任务的科学回报。在这项工作中，我们使用位于远距离制高点的软 X 射线成像仪模拟了对日侧磁层的多次同步观测，以使用动态层析方法重建磁鞘随时间变化的三维（3-D）结构。利用 OpenGCCM MHD 模型模拟磁鞘对太阳风条件的时变响应，然后从沿共同轨道分开的多个航天器有利位置生成合成软 X 射线图像。然后进行详细分析，以确定能产生最高保真度磁层切面重建的航天器标称集。这项工作的目的是：(i)首次展示利用动态断层扫描来检索随时间变化的磁鞘结构；(ii)确定以光学断层扫描为目标的多航天器配置的名义飞行任务设计。
{"title":"A feasibility study of 4-D tomography of soft X-ray magnetosheath emissivities using multi-spacecraft measurements","authors":"G. Cucho-Padin, Hyunju Connor, Jaewoong Jung, Michael Shoemaker, Kyle Murphy, D. Sibeck, Johannes Norberg, Enrique Rojas","doi":"10.3389/fspas.2024.1379321","DOIUrl":"https://doi.org/10.3389/fspas.2024.1379321","url":null,"abstract":"Upcoming heliophysics missions utilize state-of-the-art wide field-of-view (FOV) imaging technology to measure and investigate the space plasma environment on a global scale. At Earth, remote sensing of soft X-ray emissions, which are generated via the charge exchange interaction between heavy solar wind ions and exospheric neutral atoms, is a promising means to investigate the global magnetosheath structure, its response to varying solar wind conditions, and the spatiotemporal properties of the dayside magnetic reconnection. Data analysis techniques such as optical tomography can provide additional structural and time-varying information from the observed target and thus enhance the mission’s scientific return. In this work, we simulate multiple and simultaneous observations of the dayside magnetosphere using soft X-ray imagers located at long-distance vantage points to reconstruct the time-dependent, three-dimensional (3-D) structure of the magnetosheath using a dynamic tomographic approach. The OpenGCCM MHD model is used to simulate the time-varying response of the magnetosheath to solar wind conditions and, subsequently, generate synthetic soft X-ray images from multiple spacecraft vantage points separated along a common orbit. A detailed analysis is then performed to identify the nominal set of spacecraft that produces the highest fidelity tomographic reconstruction of the magnetopause. This work aims to (i) demonstrate, for the first time, the use of dynamic tomography to retrieve the time-varying magnetosheath structure and (ii) identify a nominal mission design for multi-spacecraft configurations aiming for optical tomography.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":"33 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141010790","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}
Pub Date : 2024-05-03DOI: 10.3389/fspas.2024.1412073
Caibo Hu, B. Zhu, Yaolin Shi
{"title":"Editorial: New advances in lunar and related planetary studies","authors":"Caibo Hu, B. Zhu, Yaolin Shi","doi":"10.3389/fspas.2024.1412073","DOIUrl":"https://doi.org/10.3389/fspas.2024.1412073","url":null,"abstract":"","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141016575","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}
Pub Date : 2024-03-15DOI: 10.3389/fspas.2024.1229092
Bach Viet Do, Yang Chen, XuanLong Nguyen, W. Manchester
The physics of solar flares occurring on the Sun is highly complex and far from fully understood. However, observations show that solar eruptions are associated with the intense kilogauss fields of active regions, where free energies are stored with field-aligned electric currents. With the advent of high-quality data sources such as the Geostationary Operational Environmental Satellites (GOES) and Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI), recent works on solar flare forecasting have been focusing on data-driven methods. In particular, black box machine learning and deep learning models are increasingly being adopted in which underlying data structures are not modeled explicitly. If the active regions indeed follow the same laws of physics, similar patterns should be shared among them, reflected by the observations. Yet, these black box models currently used in the literature do not explicitly characterize the heterogeneous nature of the solar flare data within and between active regions. In this paper, we propose two finite mixture models designed to capture the heterogeneous patterns of active regions and their associated solar flare events. With extensive numerical studies, we demonstrate the usefulness of our proposed method for both resolving the sample imbalance issue and modeling the heterogeneity for rare energetic solar flare events.
{"title":"Uncovering the heterogeneity of a solar flare mechanism with mixture models","authors":"Bach Viet Do, Yang Chen, XuanLong Nguyen, W. Manchester","doi":"10.3389/fspas.2024.1229092","DOIUrl":"https://doi.org/10.3389/fspas.2024.1229092","url":null,"abstract":"The physics of solar flares occurring on the Sun is highly complex and far from fully understood. However, observations show that solar eruptions are associated with the intense kilogauss fields of active regions, where free energies are stored with field-aligned electric currents. With the advent of high-quality data sources such as the Geostationary Operational Environmental Satellites (GOES) and Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI), recent works on solar flare forecasting have been focusing on data-driven methods. In particular, black box machine learning and deep learning models are increasingly being adopted in which underlying data structures are not modeled explicitly. If the active regions indeed follow the same laws of physics, similar patterns should be shared among them, reflected by the observations. Yet, these black box models currently used in the literature do not explicitly characterize the heterogeneous nature of the solar flare data within and between active regions. In this paper, we propose two finite mixture models designed to capture the heterogeneous patterns of active regions and their associated solar flare events. With extensive numerical studies, we demonstrate the usefulness of our proposed method for both resolving the sample imbalance issue and modeling the heterogeneity for rare energetic solar flare events.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237610","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}
Pub Date : 2024-03-15DOI: 10.3389/fspas.2024.1356379
Ângela R. G. Santos, D. Godoy-Rivera, Adam J. Finley, S. Mathur, Rafael A. García, S. N. Breton, A. Broomhall
While the mission’s primary goal was focused on exoplanet detection and characterization, Kepler made and continues to make extraordinary advances in stellar physics. Stellar rotation and magnetic activity are no exceptions. Kepler allowed for these properties to be determined for tens of thousands of stars from the main sequence up to the red giant branch. From photometry, this can be achieved by investigating the brightness fluctuations due to active regions, which cause surface inhomogeneities, or through asteroseismology as oscillation modes are sensitive to rotation and magnetic fields. This review summarizes the rotation and magnetic activity properties of the single main-sequence solar-like stars within the Kepler field. We contextualize the Kepler sample by comparing it to known transitions in the stellar rotation and magnetic-activity evolution, such as the convergence to the rotation sequence (from the saturated to the unsaturated regime of magnetic activity) and the Vaughan-Preston gap. While reviewing the publicly available data, we also uncover one interesting finding related to the intermediate-rotation gap seen in Kepler and other surveys. We find evidence for this rotation gap in previous ground-based data for the X-ray luminosity. Understanding the complex evolution and interplay between rotation and magnetic activity in solar-like stars is crucial, as it sheds light on fundamental processes governing stellar evolution, including the evolution of our own Sun.
开普勒任务的主要目标是系外行星的探测和定性，但它在恒星物理学方面也取得了非凡的进展，并将继续取得进展。恒星自转和磁活动也不例外。开普勒可以确定从主序列到红巨星分支的数万颗恒星的这些特性。根据光度测量，可以通过研究活动区导致的亮度波动（活动区会造成表面不均匀），或者通过小行星震荡学（震荡模式对自转和磁场非常敏感）来实现这一目标。本综述总结了开普勒星场内单颗主序太阳样恒星的自转和磁活动特性。我们将开普勒样本与恒星自转和磁活动演化过程中的已知转变（如向自转序列的收敛（从磁活动的饱和状态到不饱和状态）和沃恩-普雷斯顿缺口）进行比较，从而对开普勒样本进行背景分析。在审查公开数据的同时，我们还发现了一个与开普勒和其他巡天观测中出现的中间旋转缺口有关的有趣发现。我们在以前的 X 射线光度地面数据中发现了这种旋转间隙的证据。了解类太阳恒星的复杂演化和自转与磁活动之间的相互作用至关重要，因为它揭示了恒星演化的基本过程，包括我们太阳的演化过程。
{"title":"Kepler main-sequence solar-like stars: surface rotation and magnetic-activity evolution","authors":"Ângela R. G. Santos, D. Godoy-Rivera, Adam J. Finley, S. Mathur, Rafael A. García, S. N. Breton, A. Broomhall","doi":"10.3389/fspas.2024.1356379","DOIUrl":"https://doi.org/10.3389/fspas.2024.1356379","url":null,"abstract":"While the mission’s primary goal was focused on exoplanet detection and characterization, Kepler made and continues to make extraordinary advances in stellar physics. Stellar rotation and magnetic activity are no exceptions. Kepler allowed for these properties to be determined for tens of thousands of stars from the main sequence up to the red giant branch. From photometry, this can be achieved by investigating the brightness fluctuations due to active regions, which cause surface inhomogeneities, or through asteroseismology as oscillation modes are sensitive to rotation and magnetic fields. This review summarizes the rotation and magnetic activity properties of the single main-sequence solar-like stars within the Kepler field. We contextualize the Kepler sample by comparing it to known transitions in the stellar rotation and magnetic-activity evolution, such as the convergence to the rotation sequence (from the saturated to the unsaturated regime of magnetic activity) and the Vaughan-Preston gap. While reviewing the publicly available data, we also uncover one interesting finding related to the intermediate-rotation gap seen in Kepler and other surveys. We find evidence for this rotation gap in previous ground-based data for the X-ray luminosity. Understanding the complex evolution and interplay between rotation and magnetic activity in solar-like stars is crucial, as it sheds light on fundamental processes governing stellar evolution, including the evolution of our own Sun.","PeriodicalId":507437,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":"17 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140240486","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}
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