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Mshpy23:a user-friendly,parameterized model of magnetosheath conditions

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Earth and Planetary physics 2024年第1期8卷 89-104页

作者： jaewoong jung Hyunju Connor Andrew Dimmock Steve Sembay Andrew Read jan Soucek NASA Goddard space Flight center GreenbeltMDUSA department of Astronomy University of MarylandCollege ParkMDUSA Swedish Institude of space physics UppsalaSweden University of Leicester LeicesterUK Institute of Atmospheric physics Academy of Sciences of the Czech Republic

Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind−Magnetosphere−Ionosphere Link Explorer(SMILE)will observe magnetosheath and its boundary motion in soft X-rays for understanding magnetopause reconnection modes under various solar wind conditions after their respective launches in 2024 and *** conditions,namely,plasma density,velocity,and temperature,are key parameters for predicting and analyzing soft X-ray images from the LEXI and SMILE *** developed a userfriendly model of magnetosheath that parameterizes number density,velocity,temperature,and magnetic field by utilizing the global Magnetohydrodynamics(MHD)model as well as the pre-existing gas-dynamic and analytic *** this parameterized magnetosheath model,scientists can easily reconstruct expected soft X-ray images and utilize them for analysis of observed images of LEXI and SMILE without simulating the complicated global magnetosphere ***,we created an MHD-based magnetosheath model by running a total of 14 OpenGGCM global MHD simulations under 7 solar wind densities(1,5,10,15,20,25,and 30 cm)and 2 interplanetary magnetic field Bz components(±4 nT),and then parameterizing the results in new magnetosheath *** compared the magnetosheath model result with THEMIS statistical data and it showed good agreement with a weighted Pearson correlation coefficient greater than 0.77,especially for plasma density and plasma ***,we compiled a suite of magnetosheath models incorporating previous magnetosheath models(gas-dynamic,analytic),and did two case studies to test the *** MHD-based model was comparable to or better than the previous models while providing self-consistency among the magnetosheath ***,we constructed a tool to calculate a soft X-ray image from any given vantage point,which can support the planning and data analysis of the aforementioned LEXI and SMILE missions.A release of the code has been uploaded to a Git

关键词： magnetosheath python modeling

Implications of the Stellar Mass Density of High-z Massive Galaxies from jWST on Warm Dark Matter

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Research in Astronomy and Astrophysics 2024年第1期24卷 128-134页

作者： Hengjie Lin Yan Gong Bin Yue Xuelei Chen National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of sciences Beijing 100049China Science center for China space Station Telescope National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China department of physics College of SciencesNortheastern UniversityShenyang 110819China center for High Energy physics Peking UniversityBeijing 100871China

A significant excess of the stellar mass density at high redshift has been discovered from the early data release of james Webb space Telescope(jWST),and it may require a high star formation ***,this will lead to large number density of ionizing photons in the epoch of reionization(EoR),so that the reionization history will be changed,which can arise tension with the current EoR *** dark matter(WDM),via the free streaming effect,can suppress the formation of small-scale structure as well as low-mass *** provides an effective way to decrease the ionizing photons when considering a large star formation efficiency in high-z massive galaxies without altering the cosmic reionization *** the other hand,the constraints on the properties of WDM can be derived from the jWST *** this work,we study WDM as a possible solution to reconcile the jWST stellar mass density of high-z massive galaxies and reionization *** find that,the jWST high-z comoving cumulative stellar mass density alone has no significant preference for either CDM or WDM *** using the observational data of other stellar mass density measurements and reionization history,we obtain that the WDM particle mass with mw=0.51_(-0.12)^(+0.22) keV and star formation efficiency parameter f_(*)^(0)> 0.39 in 2σ confidence level can match both the jWST high-z comoving cumulative stellar mass density and the reionization history.

关键词： Cosmology (cosmology:)dark matter (cosmology:)large-scale structure of universe

Estimating the subsolar magnetopause position from soft X-ray images using a low-pass image filter

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Earth and Planetary physics 2024年第1期8卷 173-183页

作者： Hyangpyo Kim Hyunju K.Connor jaewoong jung Brian M.Walsh David Sibeck Kip D.Kuntz Frederick S.Porter Catriana K.Paw U Rousseau A.Nutter Ramiz Qudsi Rumi Nakamura Michael Collier space Research Institute Austrian Academy of Sciences8042 GrazAustria Geophysical Institute University of Alaska FairbanksFairbanksAlaska 99775USA National Aeronautics and space Administration(NASA)Goddard space Flight center GreenbeltMaryland 20771USA Astronomy department University of Maryland College ParkCollege ParkMaryland 20742USA center for space physics Boston UniversityBostonMassachusetts 02215USA department of physics and Astronomy Johns Hopkins UniversityBaltimoreMaryland 21218USA Howard University WashingtonDC 20059USA

The Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)missions will image the Earth’s dayside magneto pause and cusps in soft X-rays after their respective launches in the near future,to specify glo bal magnetic reconnection modes for varying solar wind *** suppo rt the success of these scientific missions,it is critical to develop techniques that extract the magnetopause locations from the observed soft X-ray *** this research,we introduce a new geometric equation that calculates the subsolar magnetopause position(RS)from a satellite position,the look direction of the instrument,and the angle at which the X-ray emission is *** assumptions are used in this method:(1)The look direction where soft X-ray emissions are maximized lies tangent to the magnetopause,and(2)the magnetopause surface near the subsolar point is almost spherical and thus RSis nea rly equal to the radius of the magneto pause *** create synthetic soft X-ray images by using the Open Geospace General Circulation Model(OpenGGCM)global magnetohydrodynamic model,the galactic background,the instrument point spread function,and Poisson *** then apply the fast Fourier transform and Gaussian low-pass filte rs to the synthetic images to re move noise and obtain accurate look angles for the soft X-ray pea *** the filte red images,we calculate RS and its accuracy for different LEXI locations,look directions,and solar wind densities by using the OpenGGCM subsolar magnetopause location as ground *** method estimates RS with an accuracy of10 *** accuracy improves for greater solar wind densities and during southward interplanetary magnetic *** method ca ptures the magnetopause motion during southwa rd interplaneta ry magnetic field ***,the technique will enable quantitative analysis of the magnetopause motion and help reveal the daysi

关键词： soft X-ray magnetopause reconnection low-pass filter LEXI SMILE

Evaluating CMIP6 models in simulating the North Pacific decadal variability in sea surface salinity

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Science China Earth sciences 2024年第8期67卷 2661-2680页

作者： jian CHEN Hailong LIU Pengfei LIN Wenrong BAI Chengzu BAI Lu WANG Institute of Atmospheric physics Chinese Academy of SciencesBeijing 100029China State Key Laboratory of Geo-Information Engineering Xi’an 710054China Beijing Municipal Climate center Beijing Meteorological BureauBeijing 100089China space System department Equipment department Beijing 100096China

The North Pacific sea surface salinity(SSS)decadal variability(NPSDV)and its potential forcing were evaluated from 25 coupled models of the Coupled Model Intercomparison Project phase 6(CMIP6)considering the prospects for decadal climate *** results indicated that the CMIP6 models generally reproduced the spatial patterns of *** large standard deviation of the SSS anomaly over the strong current regions,such as the Kuroshio-Oyashio Extension(KOE),North Pacific Current(NPC),California Current System(CCS),and Alaskan Coastal Current(ACC),is reflected in the two leading modes of NPSDV:a dipole with out-of-phase loadings in the KOE-NPC versus CCS-ACC and a monopole with positive loading over the *** order of modes is sensitive to individual models that exhibit discrepancies,especially in temporal phases and power *** autoregressive model of order-1 was used to reconstruct the NPSDV with several forcing *** generally weaker influence of forcings in an autoregressive model of order-1 is partly related to the overestimated response time of NPSDV relative to *** NPSDV variances originate from the persistence of SSS anomalies,but the dominant forcing factors are diverse among *** model diversity for the NPSDV simulation mainly arises from the influence of the tropical El Ni?o-Southern Oscillation through teleconnection on the North Pacific Oscillation or Aleutian Low with timescale ***,models that can reproduce the NPSDV well are not dependent on those with larger impacts from the North Pacific oceanic processes.

关键词： North Pacific Sea surface salinity Decadal variability CMIP6 Leading mode

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Global hybrid simulations of soft X-ray emissions in the Earth’s magnetosheath

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Earth and Planetary physics 2024年第1期8卷 47-58页

作者： jin Guo TianRan Sun San Lu QuanMing Lu Yu Lin XueYi Wang Chi Wang RongSheng Wang Kai Huang School of Earth and space sciences University of Science and Technology of ChinaHefei 230026China CAS center for Excellence in Comparative Planetology/CAS Key Lab of Geospace Environment University of Science and Technology of ChinaHefei 230026China Collaborative Innovation center of Astronautical Science and Technology Harbin 150001China National space Science center Chinese Academy of SciencesBeijing 100190China physics department Auburn UniversityAuburnALUSA

Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the *** X-ray imaging allows investigation of the large-scale magnetopause by providing a two-dimensional(2-D)global view from a *** performing 3-D global hybrid-particle-in-cell(hybrid-PIC)simulations,we obtain soft X-ray images of Earth’s magnetopause under different solar wind conditions,such as different plasma densities and directions of the southward interplanetary magnetic *** all cases,magnetic reconnection occurs at low latitude *** soft X-ray images observed by a hypothetical satellite are shown,with all of the following identified:the boundary of the magnetopause,the cusps,and the *** X-ray emissivity in the magnetosheath is characterized by large amplitude fluctuations(up to 160%);however,the maximum line-of-sight-integrated X-ray intensity matches the tangent directions of the magnetopause well,indicating that these fluctuations have limited impact on identifying the magnetopause boundary in the X-ray ***,the magnetopause boundary can be identified using multiple viewing *** also find that solar wind conditions have little effect on the magnetopause *** Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will provide X-ray images of the magnetopause for the first time,and our global hybrid-PIC simulation results can help better understand the 2-D X-ray images of the magnetopause from a 3-D perspective,with particle kinetic effects considered.

关键词： magnetopause X-ray emissivity X-ray imaging SMILE global hybrid-PIC simulation

Ground-based and additional science support for SMILE

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Earth and Planetary physics 2024年第1期8卷 275-298页

作者： j.A.Carter M.Dunlop C.Forsyth K.Oksavik E.Donovon A.Kavanagh S.E.Milan T.Sergienko R.C.Fear D.G.Sibeck M.Connors T.Yeoman X.Tan M.G.G.T.Taylor K.McWilliams j.Gjerloev R.Barnes D.D.Billet G.Chisham A.Dimmock M.P.Freeman D.-S.Han M.D.Hartinger S.-Y.W.Hsieh Z.-j.Hu M.K.james L.juusola K.Kauristie E.A.Kronberg M.Lester j.Manuel j.Matzka I.McCrea Y.Miyoshi j.Rae L.Ren F.Sigernes E.Spanswick K.Sterne A.Steuwer T.Sun M.-T.Walach B.Walsh C.Wang j.Weygand j.Wild j.Yan j.Zhang Q.-H.Zhang Planetary sciences Group School of Physics and AstronomyUniversity of LeicesterUniversity RoadLeicesterLE17RHUK Rutherford Appleton Laboratory space Science Technology Facilities CouncilOxfordshireUK School of space and Environment Beihang UniversityBeijing 100191China Key Laboratory of space Environment Monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing 100017China department of space and Climate physics UCLMullard Space Science LaboratoryHolmbury St.MaryDorkingSurreyRH56NTUK Birkeland Centre for space Science Department of Physics and Technology.University of BergenBergenNorway department of physics and Astronomy University of Calgary2500 University DriveCalgaryAlbertaCanada T2N 1N4 British Antarctic Survey CambridgeUK Swedish Institute of space physics KirunaSweden West Highfield Campus University of SouthamptonUniversity RoadSO171BJUK Goddard space Flight center NASAGreenbeltMarylandUSA Athabasca University AthabascaCanada ESTEC European Space AgencyNetherlands University of Saskatchewan SaskatoonCanada The johns Hopkins University Applied physics Laboratory LaurelMarylandUSA Swedish Institude of space physics UppsalaSE 75121Sweden Tongji University Shanghai 200092China center for space Plasma physics Space Science Institute4765 Walnut Street Suite BBoulderColorado80301USA Polar Research Institute of China Shanghai 200136China Finnish Meteorological Institute(FMI) Finland department of Earth and Environmental sciences(Geophysics) Ludwig Maximilian University of Munich(LMU)MunichTheresienstr.41MunichD-80333Germany Canadian space Agency MontrealCanada GFZ German Research Centre for Geosciences PotsdamGermany Nagoya University Institute for Space Earth Environment ResearchCenter for Integrated Data ScienceNagoyaAichiJP 464-8601 Northumbria University Newcastle upon TyneTyne and WearUK NE18ST National space Science center Chinese Academy SciencesBeijing 100190China Arctic Geophysics University Centre in Svalbard

The joint European space Agency and Chinese Academy of sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere *** these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SMILE ***,we describe current community efforts to prepare for SMILE,and the benefits and context various experiments that have explicitly expressed support for SMILE can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional Science Working Group,is facilitating these *** include constructing an online SMILE Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft *** anticipate growing interest and community engagement with the SMILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.

关键词： magnetosphere ionosphere magnetosphere-ionosphere coupling ground-based experimentation SMILE conjunctions missions

Probing the Galactic Halo with RR Lyrae Stars. VI. The Radial Velocity Curve Templates of RRc Stars

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Research in Astronomy and Astrophysics 2024年第7期24卷 121-137页

作者： Yue Huang Min Fang Gaochao Liu Xianzhong Zheng Sarah Ann Bird Yang Huang jianrong Shi jiangtao Wang Huawei Zhang Haijun Tian Haotong Zhang College of Science China Three Gorges University center for Astronomy and space sciences China Three Gorges University Purple Mountain Observatory Chinese Academy of Sciences School of Astronomy and space Science University of Science and Technology of China School of Astronomy and space Science University of Chinese Academy of Sciences CAS Key Laboratory of Optical Astronomy National Astronomical Observatories department of Astronomy School of PhysicsPeking University Kavli Institute for Astronomy and Astrophysics Peking University School of sciences Hangzhou Dianzi University

We present radial velocity（RV） curve templates of RR Lyrae first-overtone（RRc） stars constructed with the Mg I b triplet and Hα lines using time-domain Medium-Resolution Survey spectra of seven RRc stars from Large Sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） Data Release 9. Additionally, we derive the relation between the stellar RV curve amplitudes and g-band light curve amplitudes from Zwicky Transient Facility（ZTF）public survey. For those RRc stars without ZTF g-band light curves, we provide the conversions from the light curve amplitudes in ZTF r-and i-bands, Gaia G-band, and V-band from the All-Sky Automated Survey for Supernovae to those in ZTF g-band. We validate our RV curve templates using the RRc star SV Scl and find the uncertainties of systemic RV are less than 2.11 km s-1and 6.08 km s-1based on the Mg I b triplet and Hα lines,respectively. We calculate the systemic RVs of 30 RRc stars using the RV curve templates constructed with the Mg I b triplet and Hα lines and find the systemic RVs are comparable with each other. This RV curve template will be particularly useful for obtaining the systemic RV of RRc using the LAMOST spectroscopy.

关键词： Stars stars: variables: RR Lyrae techniques: radial velocities

Decoupling of temporal/spatial broadening effects in Doppler wind LiDAR by 2D spectral analysis

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Chinese physics B 2024年第3期33卷 447-452页

作者：刘珍张云鹏竹孝鹏刘继桥毕德仓陈卫标 space Laser Engineering department Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady ***,the measured spectral data are analyzed in the time dimension and frequency dimension to cope with the temporal wind shear and achieve the optimal accumulation time.A hardware-efficient algorithm combining the interpolation and cross-correlation is used to enhance the wind retrieval accuracy by reducing the frequency sampling interval and then reduce the spectral width calculation ***,the temporal broadening effect and spatial broadening effect are decoupled according to the strategy we developed.

关键词： Doppler wind LiDAR spectral analysis hardware efficiency spectrum broadening effects

Topological defects on solutions of the non-relativistic equation for extended double ring-shaped potential

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Communications in Theoretical physics 2024年第8期76卷 31-45页

作者： Badredine Boudjedaa Faizuddin Ahmed Natural sciences and Materials Laboratory University Center Abdelhafid Boussouf department of Mathematics Institute of Mathematics and Computer Science University Center Abdelhafid Boussouf department of physics University of Science & Technology Meghalaya

In this study, we focus into the non-relativistic wave equation described by the Schr?dinger equation, specifically considering angular-dependent potentials within the context of a topological defect background generated by a cosmic string. Our primary goal is to explore quasi-exactly solvable problems by introducing an extended ring-shaped potential. We utilize the Bethe ansatz method to determine the angular solutions, while the radial solutions are obtained using special functions. Our findings demonstrate that the eigenvalue solutions of quantum particles are intricately influenced by the presence of the topological defect of the cosmic string,resulting in significant modifications compared to those in a flat space background. The existence of the topological defect induces alterations in the energy spectra, disrupting ***, we extend our analysis to study the same problem in the presence of a ring-shaped potential against the background of another topological defect geometry known as a point-like global monopole. Following a similar procedure, we obtain the eigenvalue solutions and analyze the results. Remarkably, we observe that the presence of a global monopole leads to a decrease in the energy levels compared to the flat space results. In both cases, we conduct a thorough numerical analysis to validate our findings.

关键词： Bethe ansatz method non-relativistic wave-equation: Schrödinger equation point-like global monopole potential: extended ring-shaped potentials topological defect: cosmic string