Astrophysics and Space Science最新文献_第3页

Investigation of an X1.5 class solar flare associated with a 3D null - QSL system in NOAA active region 13006 NOAA活动区域13006中与三维零QSL系统相关的X1.5级太阳耀斑的研究

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-09-07 DOI: 10.1007/s10509-026-04631-y

Divya Kumari, Pawan Kumar, Sanjay Kumar, Sadashiv, Alok Ranjan Tiwary

{"title":"Investigation of an X1.5 class solar flare associated with a 3D null - QSL system in NOAA active region 13006","authors":"Divya Kumari, Pawan Kumar, Sanjay Kumar,  Sadashiv, Alok Ranjan Tiwary","doi":"10.1007/s10509-026-04631-y","DOIUrl":"10.1007/s10509-026-04631-y","url":null,"abstract":"<div><p>We investigate the magnetic topology and trigger mechanism of the X1.5-class flare hosted by NOAA Active region 13006 on 10 May 2022, combining multi-wavelength observations with a Non-Force-Free-Field (NFFF) extrapolation. Observations show a circular brightening and a remote brightening that evolve into corresponding circular and remote flare ribbons during the impulsive phase. GONG H<span>({alpha })</span> data reveal a pre-existing arc-shaped filament within the flaring region that stays stable throughout the flare and subsequently shows signs of eruption shortly afterward. The NFFF extrapolation of the active region depicts the presence of a three dimensional (3D) null exhibiting a fan-spine structure, a filament located beneath the fan dome within the flaring kernel. The extrapolated field accurately reproduces the observed coronal morphology and demonstrates a close spatial relationship between the fan foot-points and the circular ribbon. The analysis also reveals a circular quasi-separatrix layer (QSL) surrounding the fan foot-points, while enhanced <span>(|mathbf{J}|/|mathbf{B}|)</span> near the null point indicates favorable conditions for current-sheet formation and reconnection. Measurements of the photospheric magnetic flux further indicate flux cancellation beneath the fan structure during the flare, implying a gradual buildup of magnetic free energy. The flux evolution implies that the sheared arcade beneath the fan may progressively transform into a flux rope, eventually leading to eruption. We propose that the flare is triggered by slipping magnetic reconnection within the circular QSL, leading to the initial circular brightening, followed by reconnection at the 3D null that amplifies the circular ribbon and produces the remote ribbon.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148903360","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

Phase-resolved spectra of nine pulsars from ultra-wideband observations with the Parkes 64-m Radio Telescope 帕克斯64米射电望远镜超宽带观测所得的9颗脉冲星相位分辨光谱

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-09-07 DOI: 10.1007/s10509-026-04630-z

Zhaoxin Li, Andi Huang

{"title":"Phase-resolved spectra of nine pulsars from ultra-wideband observations with the Parkes 64-m Radio Telescope","authors":"Zhaoxin Li, Andi Huang","doi":"10.1007/s10509-026-04630-z","DOIUrl":"10.1007/s10509-026-04630-z","url":null,"abstract":"<div><p>Pulse profiles of pulsar can provide crucial clues about the geometry of emission beams, emission regions, and underlying radiation processes. Radio flux densities of pulsars generally follow a power law as a function of frequency. Therefore, phase-resolved spectra show the spectral indices at different pulse phases and allow inversion of particle energy distributions in emission regions to investigate radiation mechanisms. We used ultra-wideband observations from the Parkes 64-m Radio Telescope to derive multi-band pulse profiles of nine pulsars and analyze their phase-resolved spectra. Based on their morphological features, we classified these spectra into four categories (W-type, normal V-type, inverted V-type, and irregular type). Our results show that pulsars with poorly resolved single/multiple emission peaks tend to produce W-type and V-type phase-resolved spectra, while sources with distinct multi-peaked profiles generally yield irregular spectra. Phase-resolved spectra of all nine pulsars are well fitted with single- or multi-valley functions, and our results provide observational support for probing pulsar radiation mechanism.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148903638","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

Global ionospheric TEC modeling based on GNSS and FY-3E 基于GNSS和FY-3E的全球电离层TEC模拟

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-28 DOI: 10.1007/s10509-026-04629-6

Bingyue Liu, Shuhui Li, Junyin Ma, Chenghao Rao

{"title":"Global ionospheric TEC modeling based on GNSS and FY-3E","authors":"Bingyue Liu, Shuhui Li, Junyin Ma, Chenghao Rao","doi":"10.1007/s10509-026-04629-6","DOIUrl":"10.1007/s10509-026-04629-6","url":null,"abstract":"<div><p>The FengYun-3E satellite (FY-3E) is the world’s first civil morning-twilight orbiting meteorological satellite. It can overcome the spatial limitations of Ground-based Global Navigation Satellite System (GNSS) observations alone and provide critical data support for global ionospheric research. It is necessary to make full use of this data source. In this paper, we first used a deep learning model to correct the nonlinear biases in FY-3E radio occultation (RO) total electron content (TEC). Then, we integrated GNSS observations and FY-3E RO ionospheric data to model the global ionospheric TEC. Before correction, the root mean square error (RMSE) and mean absolute error (MAE) between the FY-3E RO TEC and GIM-TEC in 2025 were 5.92 TECU and 4.88 TECU, respectively. We used the 2024 data as the dataset to build a multi-channel Transformer bias correction model for FY-3E RO TEC, which is driven by temporal, spatial, solar, and geomagnetic parameters. After correction, the RMSE and MAE between the FY-3E RO TEC and GIM-TEC in 2025 are reduced to 4.26 TECU and 2.94 TECU, corresponding to improvements of 28% and 40%. We combined TEC extracted from ground-based GNSS observations with the corrected FY-3E RO data to conduct global ionospheric TEC modeling using spherical harmonic functions. Analyzing the results, we find that the model incorporating FY-3E occultation TEC significantly improves accuracy in the South Atlantic region, where the Root Mean Square (RMS) is reduced by up to 1-2 TECU under geomagnetically quiet conditions and by as much as 3.77 TECU during a geomagnetic storm.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838210","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

Correction to: The two-stream instability generation around Moon: effect of interplanetary magnetic field during solar wind - lunar plasma interaction 修正：月球周围双流不稳定的产生：太阳风-月球等离子体相互作用时行星际磁场的影响

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-27 DOI: 10.1007/s10509-026-04627-8

Vipin K. Yadav, Abhinav Singh, Rajneesh Kumar

引用次数: 0

Cosmic acceleration from generalized Chaplygin gas in (f(R,L_{m})) gravity 广义Chaplygin气体在(f(R,L_{m}))重力中的宇宙加速度

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-26 DOI: 10.1007/s10509-026-04628-7

Amit Samaddar, Meghanil Sinha, S. Surendra Singh

{"title":"Cosmic acceleration from generalized Chaplygin gas in (f(R,L_{m})) gravity","authors":"Amit Samaddar, Meghanil Sinha, S. Surendra Singh","doi":"10.1007/s10509-026-04628-7","DOIUrl":"10.1007/s10509-026-04628-7","url":null,"abstract":"<div><p>In this study, we assess the cosmological performance of the generalized Chaplygin gas model in the context of curvature–matter coupled gravity, assuming a linear relation <span>(f(R,L_{m})=frac{R}{2}+gamma L_{m})</span> for the gravitational Lagrangian. A linear matter coupling is demonstrated to be necessary for both retaining the conventional Friedmann scaling and reproducing the defining expansion features of the generalized Chaplygin gas model. The model is confronted with recent data by combining 31 CC, DESI DR2 BAO results and the Pantheon+, DES-SN5Y and Union 3 SNe Ia datasets. The analysis of combined data constrains the Hubble constant to <span>(H_{0} simeq 67.6)</span>–67.8 km s<sup>−1</sup> Mpc<sup>−1</sup>, showing stability across all dataset choices. The results imply that the GCG parameters drive a smooth evolution from matter domination toward late-time accelerated expansion. Information-criterion analysis indicates that the model remains statistically competitive with <span>(Lambda )</span>CDM. A physically viable cosmic acceleration scenario emerges: the deceleration parameter reaches <span>(q_{0} simeq -0.50)</span> at the present epoch, consistent with late-time acceleration, while the dark energy equation of state attains <span>(omega _{0} simeq -0.83)</span> and remains quintessence-like (<span>(omega > -1)</span>) at all times. Statefinder diagnostics reveal that the present Universe lies in the Chaplygin gas domain, with trajectories approaching the <span>(Lambda )</span>CDM attractor. The predicted age of the Universe, <span>(t_{0} simeq 13.1)</span>–13.6 Gyr, is fully compatible with constraints from the CMB and astrophysical estimates. The GCG within linear <span>(f(R,L_{m}))</span> gravity offers a consistent and observationally supported model for explaining the Universe’s accelerated expansion at late times.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837944","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

Distinct spin distributions of millisecond pulsars in the galactic field and globular clusters 毫秒脉冲星在星系场和球状星团中的独特自旋分布

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-26 DOI: 10.1007/s10509-026-04622-z

Shu Ma, De-Hua Wang, Cheng-Min Zhang, Shuang-Qiang Wang, Na Wang, Xiang-Han Cui, Erbil Gügercinoğlu, Yi-Yan Yang, Jian-Wei Zhang

{"title":"Distinct spin distributions of millisecond pulsars in the galactic field and globular clusters","authors":"Shu Ma, De-Hua Wang, Cheng-Min Zhang, Shuang-Qiang Wang, Na Wang, Xiang-Han Cui, Erbil Gügercinoğlu, Yi-Yan Yang, Jian-Wei Zhang","doi":"10.1007/s10509-026-04622-z","DOIUrl":"10.1007/s10509-026-04622-z","url":null,"abstract":"<div><p>To investigate the origin of the difference between the millisecond pulsars (MSPs) in the Galactic field (GF) and globular clusters (GCs), we analyzed a sample of 789 MSPs with spin periods <span>(P < 10text{ ms})</span> (495 from the GF, 294 from GCs) using Kolmogorov-Smirnov (K-S) tests. One-sample K-S tests confirm that the spin period distributions of both MSP populations are consistent with log-normal profiles, while two-sample K-S tests reveal a statistically significant difference between the two groups. Specifically, GF MSPs exhibit a shorter average spin period (<span>(mu =3.741text{ ms})</span>) with a dispersal distribution (<span>(sigma =0.185)</span>), whereas GC MSPs show a longer mean period (<span>(mu =4.121text{ ms})</span>) and greater concentrated (<span>(sigma =0.169)</span>). These discrepancies are attributed to their distinct formation and evolutionary pathways: MSP evolution in GCs is dominated by dynamical interactions within high-density, ancient stellar systems, whereas GF MSPs from post-galaxy merger and undergo accretion-driven spin-up in low-mass X-ray binaries (LMXBs). This study provides direct observational evidence for the difference of origin for MSPs across disparate Galactic environments. The distinct spin period distributions suggest that the evolutionary pathways of MSPs are strongly modulated by their host environments, which in turn reflect the different formation histories of the Galactic disk and globular clusters. Thus, MSP populations may serve as a complementary tool to study environmental differentiation in the Milky Way.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837942","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

Analysis of surface oscillations in complex solar plasmas 复杂太阳等离子体的表面振荡分析

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-25 DOI: 10.1007/s10509-026-04623-y

Souvik Das, Pralay Kumar Karmakar

{"title":"Analysis of surface oscillations in complex solar plasmas","authors":"Souvik Das, Pralay Kumar Karmakar","doi":"10.1007/s10509-026-04623-y","DOIUrl":"10.1007/s10509-026-04623-y","url":null,"abstract":"<div><p>Solar surface oscillations provide a powerful diagnostic of the Sun’s internal structure and associated plasma dynamics. In this work, we investigate the dispersion and stability properties of collective fluctuation modes in a self-gravitating, viscoturbulent, and thermally conductive solar surface plasma with suprathermal <span>(kappa )</span>-distributed electrons. A spherical normal-mode analysis yields a generalized cubic dispersion relation that consistently captures the combined non-ideal effects of electron nonthermality, thermo-plasmicity, ion non-isothermality, viscosity, turbulence, and thermal conduction. Numerical analysis reveals that stronger suprathermal electron populations (lower <span>(kappa )</span>) substantially reduce oscillation frequencies, phase velocities, and spatiotemporal spectral intermittency by promoting mode stabilization, with more pronounced effects at shorter scales. In contrast, thermo-plasmicity, introduced via the solar equilibrium-to-plasma temperature ratio, enhances mode propagation and instability by smoothing spectral gradients, thereby modifying dispersive characteristics. Dynamic (shear) viscosity, on the other hand, acts as a dominant damping mechanism, suppressing instability growth and increasing the characteristic gradient scale length of the modes. The interplay of these effects governs the balance between wave amplification and dissipation near the solar surface. The results especially highlight the physical relevance of electron nonthermality and viscosity-induced dissipation in shaping solar surface oscillation dynamics. A qualitative comparison with diverse helioseismic observations from BiSON, GONG, Hinode, and SDO/HMI, together with <i>in situ</i> measurements from the STEREO, Parker Solar Probe, and Solar Orbiter, supports the physical relevance and robustness of the present theoretical framework and its predictions.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837453","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

Retraction Note: Constraints on dark matter in neutron stars from recent observations and mass correlation analysis 最近的观测和质量相关分析对中子星暗物质的约束

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-24 DOI: 10.1007/s10509-026-04626-9

Jing Fu Hu, Hang Lu

引用次数: 0

Insights into the diversity of exoplanet atmospheres in the era of JWST 在JWST时代对系外行星大气多样性的洞察。

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-24 DOI: 10.1007/s10509-026-04624-x

Michael Radica

{"title":"Insights into the diversity of exoplanet atmospheres in the era of JWST","authors":"Michael Radica","doi":"10.1007/s10509-026-04624-x","DOIUrl":"10.1007/s10509-026-04624-x","url":null,"abstract":"<div><p>From religion to science, the quest to understand our place in the universe is one of the fundamental drivers of human progress. Since the discovery of the first exoplanet around a main sequence star in the mid-1990s, our current count of exoplanetary systems has exploded to several thousands. We have even performed in-depth studies of the atmospheres of many distant worlds, yielding insights into the previously unfathomable diversity of planets that exist in the galaxy. In this review article, I summarize work in which I developed several state-of-the-art analysis tools, and applied them to some of the first ever observations of transiting exoplanet atmospheres with the James Webb Space Telescope (JWST). These works provide clear a demonstration of JWST’s revolutionary capabilities: enabling unprecedented insights into the chemical inventory of the atmosphere of a hot-Saturn and hot-Neptune, as well as strict limits on potential atmosphere scenarios of a rocky Venus analogue. These works also encourage new standards for exoplanet data analysis and have laid the groundwork for population-level analyses of atmosphere demographics.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503497/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148817234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deep learning-based integration of multi-GNSS radio occultation using LSTM for global electron density modeling 基于深度学习的多gnss掩星集成LSTM全球电子密度建模

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-18 DOI: 10.1007/s10509-026-04618-9

Yutian Chen, Changzhi Zhai, Dongjie Yue, Xiangyu Tian

{"title":"Deep learning-based integration of multi-GNSS radio occultation using LSTM for global electron density modeling","authors":"Yutian Chen, Changzhi Zhai, Dongjie Yue, Xiangyu Tian","doi":"10.1007/s10509-026-04618-9","DOIUrl":"10.1007/s10509-026-04618-9","url":null,"abstract":"<div><p>This study develops a long short-term memory (LSTM)-based framework for global three-dimensional electron density (Ne) modeling, using long-term (2001–2019) multi-GNSS radio occultation observations with solar and geomagnetic activity indices. The model’s extrapolation capability is evaluated for 2020 using vertical electron density profiles from eight globally distributed ionosondes, while consistency with Swarm-A in situ observations is assessed under both geomagnetically quiet and disturbed conditions. The performance of the LSTM model is compared with gated recurrent unit (GRU) and standard recurrent neural network (RNN) models. Results show that LSTM outperforms both GRU and RNN, with correlation coefficients exceeding 0.9 on the test set. The root mean square error (RMSE) exhibits an altitude-dependent pattern, peaking at 250–350 km and increasing at low latitudes. During extrapolation, the deep learning models generally outperform the International Reference Ionosphere (IRI) model, with LSTM yielding the lowest overall error. Under geomagnetically quiet conditions, Swarm-A Ne observations show strong correlations (R > 0.8) with all three models, with RMSEs below <span>(0.04times 10^{6})</span> el/cm<sup>3</sup>. During disturbed periods, the correlations remain comparable, while RMSEs increase to above <span>(0.06times 10^{6})</span> el/cm<sup>3</sup>.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782397","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