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2606.19723 2026-06-19 hep-ph astro-ph.HE hep-ex 新提交

Charged Lepton Flavor Violation at Neutrino Telescopes

中微子望远镜中的带电轻子味破坏

Writasree Maitra, Carlos A. Argüelles, P. S. Bhupal Dev, Ivan Martinez-Soler, Manibrata Sen

AI总结 提出利用中微子望远镜(如IceCube)的大量宇宙线缪子样本搜索缪子到陶子的味破坏转换,基于有效场论算符给出灵敏度,并与低能实验和对撞机结果比较。

Comments 14 pages, 11 figures

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AI中文摘要

任何带电轻子味破坏(CLFV)的观测都将是超越标准模型物理的明确信号。在此,我们提出一种利用中微子望远镜及其大量宇宙线缪子样本的新型CLFV搜索。具体而言,我们使用最近IceCube的宇宙线缪子数据集,提出在IceCube探测器内部搜索缪子到陶子转换的新方法。我们通过模型无关的有效场论(EFT)算符描述的CLFV相互作用来阐述我们的想法,并给出IceCube对相关EFT能标的灵敏度。我们还考虑了EFT算符在轴矢量$Z'$相互作用下的具体实现,并展示了$Z'$质量-耦合平面上的灵敏度。我们将我们的灵敏度与低能CLFV搜索以及当前和未来对撞机实验的结果进行比较。我们还展示了下一代中微子望远镜(如IceCube-Gen2和HUNT)的预期结果,并论证中微子望远镜如何能够成为CLFV的有力互补探针。

英文摘要

Any observation of charged lepton flavor violation (CLFV) would be a clear signal of beyond-the-Standard-Model physics. Here, we propose a novel CLFV search using neutrino telescopes with their large cosmic-ray muon samples. Specifically, we use a recent IceCube cosmic-ray muon dataset and propose a new search for muon-to-tau conversion inside the IceCube detector. We illustrate our idea with CLFV interactions described by model-independent Effective Field Theory (EFT) operators and present the IceCube sensitivity on the relevant EFT scale. We also consider a specific realization of the EFT operator in terms of an axial-vector $Z'$ interaction and show sensitivities in the $Z'$ mass-coupling plane. We compare our sensitivities with those from low-energy CLFV searches, as well as from current and future collider experiments. We also show projections from next-generation neutrino telescopes, such as IceCube-Gen2 and HUNT, and demonstrate how neutrino telescopes can provide a powerful complementary probe of CLFV.

2606.19480 2026-06-19 physics.comp-ph astro-ph.CO cond-mat.stat-mech gr-qc 新提交

sft-wick: A formalism and package for Feynman-diagram expansion and evaluation in stochastic field theories

sft-wick: 随机场理论中费曼图展开与评估的形式化与软件包

Zheng Zhang

AI总结 提出sft-wick开源Python包,通过路径积分形式化随机场动力学,自动枚举拓扑不同的费曼图并计算代数系数和数值积分,验证与Langevin模拟一致。

Comments 32 pages, 5 figures, 2 tables. Submitted to Computer Physics Communications. The sft-wick package is open source and available at this https URL (https://github.com/StatFieldTheory/sft-wick)

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AI中文摘要

当随机场动力学被转化为路径积分形式时,微扰理论变得系统化,但由此产生的展开式会迅速组合爆炸。这里的目标设置包括多分量、多维场,具有矩阵传播子、张量值耦合以及由任意$n$点累积量指定的非高斯驱动噪声。Wick配对呈阶乘增长,分量索引必须通过张量值顶点进行路由。有用的输出不是原始的收缩列表,而是一个图表:每个拓扑一个条目,包含多重性、耦合和、符号和因果约束。我们提出sft-wick,一个开源的Python包,用于构建这些图表并数值计算其积分。给定一个作用量和一个可观测量,它枚举拓扑不同的费曼图,推导其代数系数,并根据用户提供的响应和累积量函数评估得到的图表积分。核心算法在路由分量索引之前枚举空间拓扑,避免了逐收缩的Wick展开。在枚举过程中强制执行响应场约束,包括消失的响应-响应收缩、Ito约定以及无因果响应回路。预测结果与直接Langevin模拟验证,在模拟的统计噪声范围内一致。

英文摘要

When stochastic field dynamics are cast into a path-integral formulation, perturbation theory becomes systematic but the resulting expansion quickly grows combinatorially large. The setting targeted here includes multi-component, multi-dimensional fields with matrix propagators, tensor-valued couplings, and non-Gaussian driving noise specified by arbitrary $n$-point cumulants. Wick pairings grow factorially, and component indices must be routed through the tensor-valued vertices. The useful output is not a raw contraction list, but a diagram table: one entry per topology, with multiplicities, coupling sums, signs, and causal constraints resolved. We present sft-wick, an open-source Python package that constructs these diagram tables and computes their integrals numerically. Given an action and an observable, it enumerates topologically distinct Feynman diagrams, derives their algebraic coefficients, and evaluates the resulting diagram integrals from user-supplied response and cumulant functions. The core algorithm enumerates spatial topologies before routing component indices, avoiding contraction-by-contraction Wick expansion. Response-field constraints, including vanishing response-response contractions, the ito prescription, and the absence of causal response loops, are enforced during enumeration. Predictions are validated against direct Langevin simulation, agreeing to within the simulation's statistical noise.

2606.19446 2026-06-19 gr-qc astro-ph.HE hep-th 新提交

Dynamical Tidal Response of Neutron Stars: from Effective Field Theory to Gravitational Waveforms

中子星的动力学潮汐响应:从有效场论到引力波波形

Thomas Apostolidis, Valerio De Luca, Leonardo Gualtieri, Takuya Katagiri, Paolo Pani, Luca Santoni

AI总结 研究中子星在频率二阶下的完全相对论性动力学潮汐响应,通过有效场论匹配得到动力学潮汐修正,发现其对晚期旋近引力波相位有不可忽略的影响,并可能影响静态Love数的推断。

Comments 30 pages, 8 figures

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AI中文摘要

我们研究了中子星在频率二阶下的完全相对论性动力学潮汐响应。结合扩展引力体的世界线有效场论和相对论性恒星模型的微扰理论,我们推导了由外部时变场诱导的潮汐形变,包括一个普适的对数运行项。在有效理论中,我们采用维数正规化,并通过一致匹配过程,首次获得了对致密双星保守动力学和引力波信号的完整领头阶动力学潮汐修正,包括除运行项外的方案依赖有限项。我们证明,在相对论性区域,动力学效应不能仅由模式激发完全捕捉。额外贡献的大小取决于恒星致密度、状态方程和运行项。对于相对较小的致密度,动力学Love数相对于静态对应物显著增强。因此,尽管它们在形式上以8阶后牛顿阶进入引力波相位,动力学潮汐效应在晚期旋近中产生不可忽略的贡献。通过Fisher矩阵分析,我们表明第三代探测器如爱因斯坦望远镜可以测量一系列中子星质量和状态方程的动力学Love数。相反,忽略这些效应可能导致静态Love数推断的显著偏差,从而影响核状态方程。我们的结果强调了动力学潮汐效应对未来探测器高精度引力波建模的重要性。

英文摘要

We investigate the fully relativistic dynamical tidal response of neutron stars up to second order in the frequency. Combining the worldline effective field theory for extended gravitating bodies with perturbation theory of relativistic stellar models, we derive the tidal deformation induced by an external time-dependent field, including a universal logarithmic running term. In the effective theory, we work in dimensional regularization and, through a consistent matching procedure, obtain for the first time the complete leading-order dynamical tidal corrections to both the conservative dynamics and the gravitational-wave signal of compact binaries, including the scheme-dependent finite terms in addition to the running. We show that, in the relativistic regime, dynamical effects cannot be fully captured by mode excitations alone. The magnitude of the additional contribution depends on the stellar compactness, the equation of state, and the running term. Dynamical Love numbers are significantly enhanced with respect to their static counterparts for relatively small compactness. As a result, although they formally enter the gravitational-wave phase at 8th post-Newtonian order, dynamical tidal effects yield a non-negligible contribution during the late inspiral. Using a Fisher-matrix analysis, we show that third-generation detectors such as the Einstein Telescope could measure dynamical Love numbers for a range of neutron-star masses and equations of state. Conversely, neglecting these effects can lead to significant biases in the inference of static Love numbers, and hence on the nuclear equation of state. Our results highlight the importance of dynamical tidal effects for high-precision gravitational-wave modeling with future detectors.

2606.19440 2026-06-19 hep-th astro-ph.CO hep-ph 新提交

Moduli Stabilisation for ADD and the Dark Dimension Scenario

ADD与暗维度场景下的模稳定化

Andreas P. Braun, Michele Cicoli, Riccardo Milioli, Roberto Valandro

AI总结 本文提出在IIB大体积场景中通过K3纤维化Calabi-Yau三折叠实现各向异性弦紧致化,稳定模场以产生一个或两个大额外维度,对应ADD和暗维度场景,并分析了模谱与唯象约束。

Comments 42 pages, 7 figures

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AI中文摘要

我们为实现在一个或两个大额外维度下的各向异性弦紧致化(对应ADD和暗维度场景)提供了模稳定化机制。这通过IIB大体积场景实现,其中指数级大的Calabi-Yau体积(以弦单位计)自然产生参数性低的Kaluza-Klein标度。各向异性通过考虑一个K3纤维化于$\mathbb{P}^1$基上的Calabi-Yau三折叠实现。通过有效作用量的微扰修正(特别是弦圈和高阶导数效应),4D K3纤维的体积被稳定在相对较小的值,而2D $\mathbb{P}^1$基的体积保持指数级大。我们论证,复结构模稳定化可以动态地使$\mathbb{P}^1$基变形,对应于Tyurin退化极限,其中内部几何有效发展出一个单一的大1D环。在统一描述中,ADD情形作为对称的替代极限恢复。势能可以具有dS真空或quintessence逃逸,尽管两种情况下都需要一定程度的调节以匹配观测到的宇宙学常数标度。我们还给出了一个显式的Calabi-Yau定向折叠例子,具有一致的膜配置、tadpole抵消和模稳定化。我们分析了所得的模谱和相关的唯象约束,包括超对称破缺、宇宙学模过产生和第五力界限。

英文摘要

We provide a moduli stabilisation mechanism for realising anisotropic string compactifications with one or two large extra dimensions, corresponding to the ADD and Dark Dimension scenarios. This is achieved within the type IIB Large Volume Scenario, where an exponentially large Calabi-Yau volume in string units can naturally generate a parametrically low Kaluza-Klein scale. Anisotropy is realised by considering a Calabi-Yau threefold which is a K3 fibration over a $\mathbb{P}^1$ base. The volume of the 4D K3 fibre is stabilised at relatively small values by perturbative corrections to the effective action, in particular string loops and higher-derivative effects, leaving an exponentially large volume of the 2D $\mathbb{P}^1$ base. We argue that complex structure moduli stabilisation can dynamically deform the $\mathbb{P}^1$ base, corresponding to a Tyurin degeneration limit where the internal geometry effectively develops a single large 1D cycle. Within a unified description, the ADD case is instead recovered as a symmetric alternative limit. The potential can feature either a dS vacuum or a quintessence runaway, although in both cases some degree of tuning is required to match the observed cosmological constant scale. We also present an explicit Calabi-Yau orientifold example with consistent brane setup, tadpole cancellation and moduli stabilisation. We analyse the resulting moduli spectrum and associated phenomenological constraints, including supersymmetry breaking, cosmological moduli overproduction and fifth force bounds.

2606.19439 2026-06-19 hep-ph astro-ph.CO 新提交

From Rags to Jeans: Axion Miniclusters from Early matter domination

从破布到牛仔:早期物质主导时期的轴子微团簇

Ariel Angulo, Paola Arias, Nicolás Bernal, Javier Redondo

AI总结 本文研究早期物质主导时期辐射浴的不均匀性通过轴子质量温度依赖性产生轴子密度扰动,导致轴子过密度在物质-辐射相等时达到量级1,并形成两种特征区域的非线性谱,估计了微团簇质量及轴子星子结构。

Comments 25+21 pages; 11 figures

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AI中文摘要

在早期物质主导时期,辐射浴的密度和温度不均匀性比标准辐射主导历史中增长更有效。如果轴子质量依赖于温度,这些不均匀性会诱导轴子质量的空间涨落,为轴子密度扰动提供新的源项。我们表明,当再加热温度刚好低于质量饱和标度 $T_\Lambda$ 时,该机制最有效,并能在物质-辐射相等时将轴子过密度驱动到量级1。对于饱和观测暗物质丰度的QCD轴子,相等时的非线性谱表现出两个特征区域:一个与模驱动宇宙学中已经存在的引力增强相关,另一个由轴子质量的温度依赖性产生。我们估计了由此产生的微团簇质量,并讨论了轴子微团簇和轴子星子结构可能形成的可能性。

英文摘要

In an early matter-dominated era, density and temperature inhomogeneities of the radiation bath grow more efficiently than in the standard radiation-dominated history. If the axion mass depends on temperature, these inhomogeneities induce spatial fluctuations of the axion mass, providing a new source term for axion density perturbations. We show that this mechanism is most efficient when the reheating temperature lies just below the mass-saturation scale $T_\Lambda$, and can drive axion overdensities to order unity by matter--radiation equality. For the QCD axion saturating the observed dark matter abundance, the nonlinear spectrum at equality exhibits two characteristic regions: one associated with the gravitational enhancement already present in moduli-driven cosmologies, and another produced by the temperature dependence of the axion mass. We estimate the resulting minicluster masses and discuss the possible formation of axion miniclusters and axion-star substructure.

2606.19403 2026-06-19 hep-ph astro-ph.CO 新提交

Emergent Gauge Symmetries in Particle Physics and Cosmology

粒子物理与宇宙学中的涌现规范对称性

Steven D. Bass

AI总结 探讨规范对称性可能源于高能标相变涌现的思想,希格斯真空稳定性暗示新临界现象,涌现标度约10^16 GeV,暗能量与马约拉纳中微子质量同阶,暗物质候选包括轴子和声子激发。

Comments Lectures presented at the 65. Jubilee Cracow School of Theoretical Physics, Zakopane, June 14-21 2025. 40 pages, to appear in Acta Physica Polonica B

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AI中文摘要

规范对称性从何而来?这些讲座发展了标准模型可能是涌现的思想,其规范对称性在紫外深处的某个相变中消失。希格斯真空的(亚)稳定性可能指向极高能标下的某些新临界现象,希格斯将LHC实验室能量与深紫外物理联系起来。在涌现情景中,暗能量标度与轻马约拉纳中微子质量大小相似。这两个量在涌现标度(约$10^{16}$ GeV)的逆幂低能展开中出现在同一阶。暗物质候选者包括轴子和涌现标度以上自由度的声子激发。这些想法的可能测试涉及中微子以及来自早期宇宙的引力波相关信号,这些信号对极高能标物理敏感。

英文摘要

Where do gauge symmetries come from? These lectures develop the idea that the Standard Model might be emergent, with its gauge symmetries dissolving in some phase transition deep in the ultraviolet. The (meta-)stability of the Higgs vacuum may be pointing to some new critical phenomena at very high energy scales, with the Higgs connecting physics at LHC laboratory energies to that in the deep ultraviolet. In the emergence scenario, the dark energy scale comes out similar to the size of light Majorana neutrino masses. These two quantities appear at the same order in a low energy expansion in inverse powers of the scale of emergence, about $10^{16}$ GeV. Dark matter candidates include axions and phonon like excitations of degrees of freedom above the scale of emergence. Possible tests of these ideas involve neutrinos as well as gravitational-waves-related signals from the early Universe, which are sensitive to physics at very high energy scales.

2606.19402 2026-06-19 physics.gen-ph astro-ph.CO gr-qc 新提交

Cosmic Structure Formation in a Viable Power-Law f(R) Gravity Model: Growth Dynamics, Stability, and Observational Signatures

可行幂律 f(R) 引力模型中的宇宙结构形成:增长动力学、稳定性与观测特征

Murli Manohar Verma

AI总结 研究幂律修正f(R)引力模型中的宇宙结构形成,通过推导修正扰动方程和分析增长因子等,发现曲率修正增强物质扰动增长,模型满足理论稳定性条件,并预测了可被未来巡天检验的观测特征。

Comments 15 Pages, 2 Figures, 8 Tables

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AI中文摘要

我们研究了幂律修正引力模型 $f(R)=R+R^{1+\delta}/R_c^\delta$ 中宇宙结构的演化,其中无量纲参数 $\delta$ 表征与广义相对论的偏离。在度规 $f(R)$ 引力框架下,研究了背景宇宙学动力学和线性物质密度扰动的演化。通过引入与额外标量自由度相关的有效引力耦合,推导了修正的扰动方程,并研究了增长因子、对数增长率、增长指数以及可观测物理量 $f\sigma_8(z)$ 的演化。结果表明,曲率修正增强了物质扰动的增长,同时对于合适的模型参数值,与观测到的晚期加速膨胀相容。通过无鬼条件、Dolgov-Kawasaki稳定性判据、正标量场质量、稳定的德西特解以及变色龙屏蔽机制,确立了模型的理论可行性。与代表性的可行 $f(R)$ 引力模型比较表明,本理论通过单一偏差参数实现了一致的宇宙学演化。预测的结构增长和有效引力耦合的变化提供了可观测特征,可由即将进行的大尺度结构和弱引力透镜巡天检验,从而提供检验曲率修正引力的手段。

英文摘要

We investigate the evolution of cosmic structures in the power-law modified gravity model $f(R)=R+R^{1+\delta}/R_c^\delta$, where the dimensionless parameter $\delta$ characterizes deviations from General Relativity. The background cosmological dynamics and the evolution of linear matter density perturbations are studied within the framework of metric $f(R)$ gravity. The modified perturbation equation is derived by introducing an effective gravitational coupling associated with the additional scalar degree of freedom, and the evolution of the growth factor, logarithmic growth rate, growth index, and the observable quantity $f\sigma_8(z)$ are investigated. The results show that the curvature correction enhances the growth of matter perturbations while remaining compatible with the observed late-time accelerated expansion for suitable values of the model parameter. The theoretical viability of the model is established through the ghost-free condition, Dolgov--Kawasaki stability criterion, positive scalaron mass, stable de Sitter solution, and chameleon screening mechanism. Comparison with representative viable $f(R)$ gravity models shows that the present theory achieves a consistent cosmological evolution with a single deviation parameter. The predicted modifications in the growth of structures and the effective gravitational coupling provide observable signatures that can be tested by forthcoming large-scale structure and weak-lensing surveys, providing a means to test curvature-induced modifications of gravity.

2606.20555 2026-06-19 astro-ph.SR astro-ph.IM 新提交

Incorporating physical source parameters into microlensing modeling

将物理源参数纳入微引力透镜建模

Mateusz J. Mróz, Radosław Poleski, Andrzej Udalski, Jan Skowron, Paweł Pietrukowicz, Michał K. Szymański, Przemek Mróz, Mariusz Gromadzki, Patryk Iwanek, Szymon Kozłowski, Milena Ratajczak, Krzysztof A. Rybicki, Dorota M. Skowron, Igor Soszyński, Krzysztof Ulaczyk, Marcin Wrona, Zofia Buzik

AI总结 针对微引力透镜建模中的简并问题,提出在MCMC拟合中直接采样源星物理参数(质量、演化阶段等)的新方法,利用MIST模型施加天体物理约束,在OGLE-2017-BLG-0114事件中显著改进了爱因斯坦环半径估计。

Comments 15 pages, 6 figures

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AI中文摘要

复杂微引力透镜事件的建模存在许多难以区分的简并问题,尤其是双星系统中源星的轨道运动(即所谓的xallarap效应)。为了解决xallarap建模中固有的简并性,我们开发了一种新方法,在MCMC拟合过程中直接采样源星的物理参数(初始质量、演化阶段、金属丰度、距离和红化)。在我们的方法中,源星的物理参数通过MIST恒星演化模型进行估计。这种参数化施加了天体物理约束,有助于识别物理上最可能的解。我们在复杂微引力透镜事件OGLE-2017-BLG-0114上测试了该方法,该事件显示出可追溯至源系统复杂性的特征。我们成功约束了微引力透镜模型,在双源模型情况下,爱因斯坦环半径的估计改进了一个数量级。

英文摘要

Modeling of complex microlensing events suffers from many difficult-to-disentangle degeneracies. This is especially the case for orbital motion of the source in a binary system, the so-called xallarap effect. To address the degeneracies inherent in xallarap modeling, we developed a novel approach that directly samples the physical parameters of the source stars (initial mass, evolutionary phase, metallicity, distance, and reddening) during MCMC fitting. In our approach the physical parameters of the source are estimated using MIST stellar evolution models. This parametrization imposes astrophysical constraints that help identify the physically most probable solutions. We test our method on the complex microlensing event OGLE-2017-BLG-0114, which exhibits signatures that can be traced to the complexity of the source system. We successfully constrained the microlensing models, achieving improvements in the Einstein ring radius estimates by up to an order of magnitude in the case of binary source models.

2606.20499 2026-06-19 astro-ph.SR 新提交

A Be-shell star rotating at the critical limit and a partially stripped companion in a post-mass-transfer solution for the eclipsing binary V505 Mon

临界极限旋转的Be壳星与部分剥离伴星:食双星V505 Mon的质后转移解

Norbert Hauck

AI总结 研究食双星V505 Mon,通过TESS数据确定Be星和伴星温度、半径、质量,发现Be星以临界速度旋转并拥有大星周盘,伴星为收缩热亚矮星前身。

Comments 6 pages including 2 tables and 4 figures. Accepted for publication in 2026, BAV Rundbrief, 3, 105

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AI中文摘要

在对食壳星双星HD 48914 (V505 Mon)的研究中,通过无偏确定伴星表面温度以及TESS任务的新数据,完善了现有的测光和视向速度数据。对于我们的赤道视角下的平均有效温度、极/赤道半径和质量,我们得到Be星约为16000 K(变暗)、4.27/6.37 Rsun和7.40 Msun,伴星(一颗收缩的热亚矮星前身)约为14400 K、6.19/7.17 Rsun和2.03 Msun。计算出的它们旋转赤道速度都高得惊人:Be星以离心极限旋转,速度为467 km/s,而其前身供体星伴星为131 km/s。Be星被一个半径约65 Rsun的大型赤道去吸积盘包围,并符合亚太阳金属丰度Z=0.006的恒星模型主序带。

英文摘要

In this study of the eclipsing shell star binary HD 48914 (V505 Mon) existing photometric and radial velocity data have been completed by an unbiased determination of the surface temperature of the companion star and new data from the TESS mission. For the mean effective temperatures in our equatorial view, polar/equatorial radii and masses we get about 16000 K (dimmed), 4.27 / 6.37 Rsun and 7.40 Msun for the Be star, and about 14400 K, 6.19 / 7.17 Rsun and 2.03 Msun for the companion star (a contracting hot subdwarf precursor). Their calculated rotational equatorial velocities both are surprisingly high: 467 km/s for the Be star rotating at its centrifugal limit as well as 131 km/s for its former donor star companion. The Be star is surrounded by a large equatorial decretion disk having a radius of about 65 Rsun and fits into the main sequence of stellar models at a sub-solar metallicity of Z = 0.006.

2606.20471 2026-06-19 astro-ph.CO 新提交

The impact of FRB dispersion measure probability distribution functions on cosmographic estimates

FRB色散测量概率分布函数对宇宙学估计的影响

Thais Lemos, Rodrigo Gonçalves, Jailson Alcaniz

AI总结 利用106个快速射电暴的宇宙学方法,研究IGM色散测量概率分布函数对哈勃常数、减速参数和急动参数估计的影响,发现约束对分布形式和参数先验敏感。

Comments 22 pages, 5 figures, 6 tables

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AI中文摘要

近期的宇宙学观测重新引发了关于哪种模型最能描述宇宙动力学的讨论,凸显了进行宇宙学模型无关分析的必要性。本文采用宇宙学方法,利用红移范围$z \le 0.7$内106个定位良好的快速射电暴(FRB)样本,约束哈勃常数$H_0$、减速参数$q_0$和急动参数$j_0$。我们的主要目标是评估星系际介质(IGM)不均匀性对宇宙学参数估计的影响。为此,我们考虑了两种不同的IGM色散测量($\mathrm{DM_{IGM}}$)概率密度函数(PDF)形式下这些参数的统计行为:高斯分布(分布I)和准高斯分布(分布II),后者考虑了视线方向宇宙大尺度环境的偏斜结构。我们进一步通过考虑固定和自由参数两种情况,研究了重子质量分数的作用。我们发现,推断出的宇宙学约束,特别是对$q_0$的约束,敏感地依赖于假定的IGM分布和采用的参数先验。

英文摘要

Recent cosmological observations have reopened the discussion about the model that best describes the dynamics of the Universe, highlighting the need for cosmological model-independent analyses. In this paper, we utilize the cosmographic approach applied to a robust sample of 106 well-localized Fast Radio Bursts (FRBs) within the redshift range $z \le 0.7$ to constrain the Hubble constant $H_0$, the deceleration parameter $q_0$, and the jerk parameter $j_0$. Our primary goal is to assess the impact of intergalactic medium (IGM) inhomogeneities on cosmographic parameter estimation. To this end, we consider the statistical behavior of these parameters under two distinct functional forms for the IGM dispersion measure ($\mathrm{DM_{IGM}}$) probability density function (PDF): a Gaussian distribution (Distribution I) and a quasi-Gaussian distribution (Distribution II) that accounts for the skewed structure of cosmic large-scale environments along the lines of sight. We further investigate the role of the baryon mass fraction by considering both fixed and free-parameter scenarios. We find that the inferred cosmographic constraints, particularly those on $q_0$, depend sensitively on both the assumed IGM distribution and the adopted parameter priors.

2606.20464 2026-06-19 astro-ph.EP 新提交

Atmospheric diversity of sub-Neptunes from formation with rock, water, and soot

亚海王星大气多样性:由岩石、水和烟尘形成

Caroline Dorn, Aaron Werlen, Sean Jordan

AI总结 研究通过模拟不同比例岩石、水和烟尘形成的亚海王星,揭示其内部和大气成分如何受形成环境影响,并与JWST观测对比解释大气多样性。

Comments submitted to A&A, 10 pages, 5 figures, comments welcome

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AI中文摘要

近期JWST在亚海王星大气中探测到CH4和CO2,表明大气成分与行星构建块(岩石、水或难熔碳“烟尘”)的性质之间存在联系,但这种联系仍知之甚少。本文研究不同形成环境如何塑造亚海王星的耦合内部和大气成分。我们模拟由不同比例的岩石、水和烟尘组装的行星,计算全局化学平衡和覆盖的大气结构。我们发现,由贫水物质形成的行星产生的大气中碳物种严重贫化,log(CH4)和log(CO2)低于-4。相反,由富水构建块组装的行星自然发展出富含甲烷和二氧化碳的大气,具有较高的金属质量分数和C/O比。难熔碳(烟尘)的存在进一步增强了甲烷的产生,并可能导致以甲烷为主的大气。与JWST观测的比较表明,富水形成足以解释K2-18b和TOI-270d,无需烟尘组分,而TOI-421b和GJ3470b与冰线内贫水形成一致。H2O/CH4比与平均分子量(MMW)结合提供了一个强大的二维诊断,将大气成分与形成环境联系起来,偏离预测趋势可由温带大气中的水凝结或分馏的大气质量损失解释。

英文摘要

Recent JWST detections of CH4 and CO2 in sub-Neptune atmospheres point to a link between atmospheric composition and the nature of planetary building blocks - rock, water, or refractory carbon ("soot") - yet this connection remains poorly understood. Here we investigate how different formation environments shape the coupled interior and atmospheric compositions of sub-Neptunes. We model planets assembled from varying proportions of rock, water, and soot and compute the global chemical equilibrium and the overlying atmospheric structure. We find that planets formed from water-poor material produce atmospheres strongly depleted in carbon-bearing species, with log(CH4) and log(CO2) below -4. In contrast, planets assembled from water-rich building blocks naturally develop methane- and carbon-dioxide-rich atmospheres with elevated metal mass fractions and C/O ratios. The presence of refractory carbon (soot) further enhances methane production and can lead to methane-dominated atmospheres. Comparison with JWST observations suggests that water-rich formation is sufficient to explain K2-18b and TOI-270d with no soot component required, while TOI-421b and GJ3470b are consistent with water-poor formation inside the water ice line. The ratio H2O/CH4 combined with the mean molecular weight (MMW) provides a powerful two-dimensional diagnostic linking atmospheric composition to formation environment, with departures from the predicted trends explained by water condensation in temperate atmospheres or fractionated atmospheric mass loss.

2606.20434 2026-06-19 astro-ph.CO 新提交

The Hubble tension: A decade review

哈勃常数张力:十年综述

Rong-Gen Cai, Shao-Jiang Wang

AI总结 综述哈勃常数张力的现状,探讨早期与晚期宇宙观测差异的起源,并评述通过修改声视界、超新星绝对星等或相互作用暗能量模型等解决方案。

Comments 76 pages, 5 figures, 1 table; Comments are welcome for missing important citations; Invited review for RAA (Research in Astronomy and Astrophysics), prepared for the Special Forum: "Dark Energy and the Hubble Constant Crisis" at the 28th Annual Conference of the China Association for Science and Technology

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AI中文摘要

自新千年以来,精密宇宙学将$\Lambda$冷暗物质($\Lambda$CDM)模型塑造为协和宇宙学的标准模型,该模型经受住了各种检验,但早期宇宙观测与晚期宇宙测量之间关于当前可观测宇宙哈勃膨胀率的差异日益扩大。这一哈勃常数张力可能已成为现代宇宙学的真正危机,无论早期宇宙观测是否依赖于\textit{Planck} CMB,以及晚期宇宙测量是否依赖于距离阶梯,该差异持续存在。如果哈勃张力源于不同的早期宇宙,其解决方案涉及通过改变早期膨胀或复合历史来缩小声视界,但同时需要对原初和晚期宇宙进行整体修改。或者,如果哈勃张力源于不同的晚期宇宙,其解决方案通过内在或有效改变超新星绝对星等来运作,这两种方式都受到宇宙距离对偶关系的逆距离阶梯的强烈约束。剩下的选择似乎转向我们的局部宇宙,但局部哈勃气泡或宇宙空洞解决方案早已被排除作为哈勃张力的重要贡献。鉴于这一困境,本文综述了涉及相互作用暗能量模型的替代解决方案,这些方案要么结合早期和晚期修改,要么在从非均匀性到均匀性尺度的过渡中运作。

英文摘要

Ever since the new millennium, precision cosmology has forged the $\Lambda$-cold-dark-matter ($\Lambda$CDM) model as the standard model of concordant cosmology, withstanding various tests except for an ever-enlarging discrepancy between early-Universe observations and late-Universe measurements on the current Hubble expansion rate of our observable Universe. This Hubble-constant tension has likely become a real crisis for modern cosmology, with the discrepancy persisting regardless of whether the early-Universe observations depend on \textit{Planck} CMB or not, and the late-Universe measurements depend on distance ladders at all. If the Hubble tension originates from a different early Universe, its resolutions pertain to shrinking the sound horizon by altering either early expansion or recombination histories, but at the same time necessitating modifications to both primordial and late Universe altogether. Alternatively, if the Hubble tension arises from a different late Universe, its resolutions operate by changing the absolute magnitude of supernovae either intrinsically or effectively, both of which have been strongly constrained by the inverse distance ladders with the cosmic distance duality relation. The remaining options seem to turn to our local Universe, but a local Hubble bubble or cosmic void solution has long been ruled out as a significant contribution to the Hubble tension. In view of this dilemma, we review in this paper alternative resolutions involving interacting dark energy models, either combining early-time and late-time modifications or operating at the transition from inhomogeneity to homogeneity scales.

2606.20398 2026-06-19 astro-ph.EP 新提交

Giant impact between high-viscosity Theia and low-viscosity proto-Earth: Origin of lunar isotopic crisis

高粘度忒伊亚与低粘度原地球之间的巨大撞击:月球同位素危机的起源

Wenshuai Liu

AI总结 通过模拟高粘度忒伊亚撞击低粘度原地球,发现产生的碎屑盘主要来自原地球,且不违反角动量约束,从而解释了月球同位素危机。

Comments 3 pages, 2 figures

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AI中文摘要

根据巨大撞击理论,月球是由忒伊亚与原地球碰撞产生的碎屑盘吸积形成的。尽管该理论解释了地月系统的大部分特征,但对行星胚胎与吸积中的原地球之间碰撞的数值模拟表明,此类撞击产生的环地盘中超过40%的物质来自撞击体。这给巨大撞击理论解释月球的地球样同位素组成带来了挑战,这一差异被称为月球同位素危机。由于类地行星在吸积过程中会熔化一次或多次,成长中的行星表面会出现岩浆洋。带有岩浆洋的小型类地行星比大型类地行星冷却得更快,导致小型类地行星的粘度大于仍被岩浆洋覆盖的大型类地行星。这里表明,高粘度忒伊亚与低粘度原地球之间的巨大撞击可以产生主要由原地球物质组成的环地碎屑盘,且不违反现代地月系统的角动量约束。这里提出的理论可能为解释月球同位素危机提供一种自然的方式。

英文摘要

According to the giant impact theory, the Moon was formed by accretion of the debris disk that resulted from the collision between Theia and the proto-Earth. Although this theory accounts for most characteristics of the Earth-Moon system, numerical simulations of impacts between a planetary embryo and the accreting proto-Earth indicate that more than 40 percent of the material in the circum-terrestrial disk generated by such an impact originates from the impactor. This poses a challenge for the giant impact theory in explaining the Moon's Earth-like isotopic composition, a discrepancy known as the lunar isotopic crisis. Since terrestrial planets were melted one or more times during accretionary processes, magma ocean on the surface of a growing planet would appear. Small terrestrial planets with magma ocean cool faster than large ones, resulting that the viscosity of small terrestrial planets is larger than that of large terrestrial planets still covered by magma ocean. Here, it shows that giant impact between a high-viscosity Theia and a low-viscosity proto-Earth could produce a circum-terrestrial debris disk predominantly composed of material from the proto-Earth without violating the angular momentum constraint of modern Earth-Moon system. The theory proposed here may provide a natural way of explaining the lunar isotopic crisis.

2606.20370 2026-06-19 astro-ph.IM astro-ph.GA 新提交

ELMA: ELlipse-based bar MAjor axis estimator

ELMA:基于椭圆的棒主轴估计器

Bruna R. Bragança de Lima, Andressa Wille, Rafael S. de Souza, Ana L. Chies-Santos

AI总结 提出ELMA Python包,通过迭代椭圆等照度线拟合自动估计星系棒长度,在GOODS-South的JWST/NIRCam图像上验证。

Comments 4 pages, 1 figure, published in RNAAS

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AI中文摘要

星系棒是盘星系中关键的非轴对称结构,驱动角动量重新分布,并促进长期演化、中心质量积累以及核结构的形成。然而,对棒长度的稳健且均匀的测量仍然具有挑战性,特别是在大型成像巡天中,人工估计耗时且对方法选择敏感。我们推出了elma,一个独立的、可通过pip安装的Python包,用于自动估计已被识别为候选棒状系统的星系中的棒长度。该方法直接对二维成像数据进行操作,使用迭代椭圆等照度线拟合来追踪径向椭圆率轮廓,并从与椭圆率局部最大值对应的半长轴中识别出投影棒长度估计值。利用图像的WCS信息和用户提供的红移,elma将角度测量值转换为投影物理长度。我们在GOODS-South天区的JWST/NIRCam成像的棒状星系上演示了该包。代码在MIT许可下发布在Github仓库中。

英文摘要

Galactic bars are key non-axisymmetric structures in disk galaxies, driving angular-momentum redistribution and contributing to secular evolution, central mass build-up, and the formation of nuclear structures. Robust and homogeneous measurements of bar length, however, remain challenging, particularly for large imaging surveys, where manual estimates are time-consuming and sensitive to methodological choices. We introduce elma, a standalone, pip-installable Python package for automated bar-length estimation in galaxies already identified as candidate barred systems. The method operates directly on two-dimensional imaging data, using iterative elliptical-isophote fitting to trace the radial ellipticity profile and identify a projected bar-length estimate from the semi-major axis associated with the local maximum in ellipticity. Using the image WCS information and a user-supplied redshift, elma converts angular measurement into a projected physical length. We demonstrate the package on JWST/NIRCam imaging of barred galaxies in the GOODS-South field. The code is released under the MIT license at a repository in Github.

2606.20368 2026-06-19 astro-ph.SR 新提交

DEM analysis of the 6 September 2011 large-scale coronal wave

2011年9月6日大规模日冕波的DEM分析

Amaia Razquin, Astrid M. Veronig, Karin Dissauer

AI总结 利用DEM诊断分析2011年9月6日X2.1级耀斑伴随的快速日冕波,发现波前密度增加6-8%、温度增加10-18%,温度增加超出绝热加热预期,暗示存在额外加热机制;波前暂时消失主要由CME相关日冕暗化与加热共同导致。

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AI中文摘要

大规模日冕波是极紫外(EUV)和软X射线(SXR)观测中全球传播的强度增强现象,与太阳耀斑和日冕物质抛射(CME)相关,被解释为大振幅快磁声波的低日冕特征。2011年9月6日,一次快速(v=1000 km/s)大规模日冕波伴随一次X2.1级爆发耀斑。波前的一部分在敏感于宁静太阳等离子体的EUV通道中暂时消失,而在更高温度通道中仍然可见。我们应用微分发射测量(DEM)诊断方法对SDO/AIA的EUV观测进行分析,推导局部密度、温度、发射测量和DEM分布,并检查它们在波通过期间的时变演化。波通过导致密度增加6-8%,温度增加10-18%。虽然密度增加与早期报告相当,但温度增加超出预期。这表明温度增强不能仅由压缩绝热加热解释,而是暗示存在额外加热机制,如磁重联或波模转换。在波暂时消失期间,波前的等离子体参数增加,但空间变化强烈,密度增加范围从1%到10%。受影响区域的初始温度显著高于典型宁静太阳区域(T>1.7 MK),这使得等离子体被加热到超过AIA 193和211 Å通道的峰值响应。我们得出结论,波前的明显暂时消失主要是由于CME相关的日冕暗化(跟随波)与波本身的强度综合效应,而加热进一步降低了其在敏感于宁静太阳温度的通道中的可探测性。

英文摘要

Large-scale coronal waves are globally propagating intensity enhancements in extreme-ultraviolet (EUV) and soft X-ray (SXR) observations, associated with solar flares and coronal mass ejections (CMEs). They are interpreted as low-coronal signatures of a large-amplitude fast magnetosonic wave. On 6 September 2011, a fast (v = 1000 km/s) large-scale coronal wave accompanied an eruptive X2.1 class flare. A segment of the wave front temporarily dissappeared in EUV channels sensitive to quiet-Sun plasma, while it remained visible in higher temperature channels. We apply differential emission measure (DEM) diagnostics to SDO/AIA EUV observations to derive local density, temperature, emission measure, and DEM distributions, and examine their temporal evolution during the wave passage. The wave passage causes increases of 6-8% in density and 10-18% in temperature. While the density increase is comparable to earlier reports, the temperature increase exceeds expectations. This indicates that the temperature enhancement cannot be explained by compressional adiabatic heating alone, and instead suggests the presence of additional heating mechanisms, such as magnetic reconnection or wave mode conversion. During the temporary disappearance of the wave, the plasma parameters at the wave front increase, but with a strong spatial variability, with density increases ranging from 1% to 10%. The initial temperature in the affected area is notably higher than typical quiet-Sun regions (T > 1.7 MK), which allows plasma to be heated beyond the peak response of the AIA 193 and 211 Åchannels. We conclude that the apparent temporary disappearance of the wave front is primarily due to the combined effects in the intensity of the CME-associated coronal dimming following the wave and the wave itself, with heating further reducing its detectability in channels sensitive to quiet-Sun temperatures.

2606.20366 2026-06-19 astro-ph.IM 新提交

Advancing Astrophysics with the SKA II

利用SKA II推进天体物理学

Anna Bonaldi, Tyler L. Bourke, Philippa Hartley, Tao An, Marc Audard, Olga Bayandina, Nicola Bellomo, Eleonora Bianchi, Marta Burgay, Joseph Callingham, Stefano Camera, Viviana Casasola, Virginia Cuciti, Philippa Cole, Neeraj Gupta, Catherine L. Hale, Ian Harrison, Jason Hessels, Tim Huege, Bhal Chandra Joshi, Aris Karastergiou, Dharam Lal, Adrian Liu, James Miller-Jones, S. A. Mao, Javier Moldon, Leah K. Morabito, Katharine Mulrey, Shane O'Sullivan, Divya Oberoi, D.J. Pisano, Kaustubh Rajwade, Mark T. Sargent, Rohit Sharma, Marta Spinelli, Xiaohui Sun, Fatemeh S. Tabatabaei, Cathryn Trott, Jacco Th. van Loon, Tessa Vernstrom, Jeff Wagg, Jing Wang, Ke Wang, Sven Wedemeyer, Jennifer L. West, Patrick Woudt, Jun Yang, Pietro Zucca

AI总结 本文概述了SKA望远镜将实现的变革性科学进展,总结了SKA-Mid和SKA-Low在射电天文学中的广泛研究,并介绍了科学工作组提供的背景框架。

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AI中文摘要

由我们的科学界撰写的《利用SKA II推进天体物理学》(AASKAII)概述了SKA望远镜将实现的变革性科学进展。自上一版出版以来的十年间,望远镜设计已成熟,建设已开始,SKA组织已演变为SKA天文台(SKAO)。同时,来自SKA前身和探路者望远镜的观测为长期存在的科学挑战提供了新见解,同时揭示了全新的现象。在SKA天文台首次科学验证活动之前出版,本卷展望了射电天文学未来几十年的发现与创新。AASKAII涵盖了SKA-Mid和SKA-Low望远镜所支持的广泛科学研究。这些贡献根据其科学重点分为六个主题类别。开篇部分介绍了SKA科学工作组的概述章节,我们的社区围绕这些工作组组织。每个概述提供了更广泛的背景,将本卷中的贡献与各自社区正在探索的关键科学问题联系起来。

英文摘要

Advancing Astrophysics with the SKA II (AASKAII), written by our science community, outlines the transformative scientific advances that will be enabled by the SKA telescopes. In the decade since the publication of the previous edition, telescope designs have matured, construction has commenced, and the SKA Organisation has evolved into the SKA Observatory (SKAO). At the same time, observations from SKA precursor and pathfinder telescopes have provided new insights into longstanding scientific challenges while revealing entirely new phenomena. Published in advance of the first science verification campaign for the SKA Observatory, this volume looks ahead to the coming decades of discovery and innovation in radio astronomy. AASKAII spans the broad range of scientific research enabled by the SKA telescopes, SKA-Mid and SKA-Low. The contributions are organised into six thematic categories according to their scientific focus. The opening section presents overview chapters from the SKA Science Working Groups, around which our community is organised. Each overview provides the broader context that connects the contributions in this volume to the key scientific questions being pursued by their respective communities.

2606.20360 2026-06-19 astro-ph.IM 新提交

Lightstack: A Python Package for Creating Photometric Data Cubes

Lightstack: 用于创建测光数据立方体的Python包

Andressa Wille, Rafael S. de Souza, Ana L. Chies-Santos, Thallis Pessi, Emille E. O. Ishida, Alberto Krone-Martins

AI总结 提出Lightstack Python包,通过裁剪、堆叠和PSF匹配三步将独立图像组合成测光数据立方体,支持多波段测光研究。

Comments 4 pages, 1 figure, published in RNAAS

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AI中文摘要

多波段测光追踪了跨广泛波长的多种物理过程。近几十年来,这一领域由多成像数据集的快速增长所驱动,例如来自哈勃空间望远镜和詹姆斯·韦伯空间望远镜的高分辨率观测,以及即将由罗曼空间望远镜和鲁宾天文台实现的大规模巡天。在这项工作中,我们介绍了lightstack,一个用于将独立图像组合成测光数据立方体的Python包。工作流程包括三个主要步骤:从所有可用滤光片的拼接图像中裁剪感兴趣区域;堆叠图像以构建数据立方体;对立方体执行PSF匹配。该包旨在为涉及多波段测光的研究准备数据。代码以MIT许可证发布,并在GitHub上提供,同时附有Jupyter教程笔记本。本出版物使用的版本(v0.2.1)已存档于Zenodo。

英文摘要

Multi-band photometry traces diverse physical processes across a wide range of wavelengths. In recent decades, this field has been driven by the rapid growth of multi-imaging datasets, from high-resolution observation from Hubble Space Telescope and James Webb Space Telescope to the forthcoming large-scale surveys enabled by the Roman Space Telescope and Rubin Observatory, for example. In this work, we present lightstack, a Python package for combining standalone images into photometric data cubes. The workflow consists of three main steps: cropping a region of interest from a mosaic across all available filters; stacking the images to construct the data cube; and performing PSF matching on the cube. This package is intended for preparing data for studies involving multi-band photometry. The code is released under an MIT license and is available on GitHub together with a Jupyter tutorial notebook. The version used for this publication (v0.2.1) is archived on Zenodo.

2606.20355 2026-06-19 astro-ph.EP astro-ph.SR 新提交

A long-term spectro-temporal study of Jovian X-ray and Ultraviolet response to solar activity

木星X射线和紫外线对太阳活动响应的长期光谱-时间研究

Megha Tomer (IIT Hyderabad), Mayukh Pahari (IIT Hyderabad), Anurag Baruah (IIT Hyderabad), Renu Malhotra (University of Arizona)

AI总结 通过分析51个高信噪比紫外光谱和29个Chandra观测,发现木星Lyα发射与太阳活动密切相关,而电离紫外线谱线无相关性;X射线耀斑在日冕物质抛射后7-15天出现,并检测到Ne⁸⁺发射特征,表明CME驱动木星极光激发。

Comments 17 pages, 13 figures, 4 tables, accepted for publication in MNRAS

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AI中文摘要

我们展示了利用太阳X射线通量和太阳黑子数作为活动指标,以及来自国际紫外线探测器(IUE;1978-1996)和钱德拉X射线天文台(2011-2021)的紫外和X射线观测,对太阳活动驱动的木星发射变异性进行的多十年研究结果。对跨越两个太阳周期的51个高信噪比紫外光谱的分析表明,木星的Lyα发射包含窄分量和宽分量,可能分别与盘面和极光区域相关。Lyα线和1330-1400埃连续谱通量在连续两个太阳周期的所有阶段都密切跟随太阳X射线通量和太阳黑子数的变化,表明与太阳辐照过程直接相关,包括太阳Lyα光子的共振散射和光电子驱动的大气激发。相比之下,电离紫外线谱线如Fe II(1608埃和1575埃)在一个太阳周期内与太阳活动没有相关性,表明其起源于内部或磁层,可能与来自Io的带电粒子或紫外/X射线辐射有关。为了确定木星的X射线响应是否类似于其对太阳活动的紫外响应,我们分析了2014-2021年间获得的29次Chandra/HRC观测和2011年的两次Chandra/ACIS观测。在报告的重大日冕物质抛射(CME)后7-15天,ACIS和HRC光变曲线中都检测到显著的X射线耀斑。CME后的ACIS极光光谱在木星北极附近70-80°纬度处显示出一个显著的(≥3σ)Ne⁸⁺发射特征(~0.94-0.98 keV)。由于所需的高电离能(Ne VIII到Ne IX的束缚-束缚跃迁约为1.19 keV),该特征不太可能来自局部相互作用,支持CME驱动的木星极光激发。

英文摘要

We present results from a multi-decade investigation of solar activity-driven variability in Jupiter's emissions, using solar X-ray flux and sunspot numbers as activity indicators and ultraviolet (UV) and X-ray observations from the International Ultraviolet Explorer (IUE; 1978-1996) and the Chandra X-ray Observatory (2011-2021). Analysis of 51 high-SNR UV spectra spanning two solar cycles shows that Jupiter's Ly$\alpha$ emission contains narrow and broad components, likely associated with the disk and auroral regions, respectively. The Ly$\alpha$ line and the 1330-1400 Angstrom continuum flux closely follow variations in solar X-ray flux and sunspot numbers throughout all phases of two consecutive solar cycles, indicating a direct connection with solar irradiation processes, including resonant scattering of solar Ly$\alpha$ photons and photoelectron-driven atmospheric excitation. In contrast, ionised UV lines such as Fe II (1608 Angstrom and 1575 Angstrom) show no correlation with solar activity over a solar cycle, suggesting an internal or magnetospheric origin, potentially linked to Io-derived charged particles or UV/X-ray radiation. To determine whether Jupiter's X-ray response resembles its UV response to solar activity, we analysed 29 Chandra/HRC observations obtained during 2014-2021 and two Chandra/ACIS observations from 2011. Significant X-ray flares are detected in both ACIS and HRC lightcurves 7-15 days after major reported coronal mass ejections (CMEs). Post-CME ACIS auroral spectra reveal a significant ($\geq 3\sigma$) Ne$^{8+}$ emission feature ($\sim$0.94-0.98 keV) near 70-80$^\circ$ latitude at Jupiter's north pole. Owing to the high ionisation energy required ($\sim$1.19 keV for the Ne VIII to Ne IX bound-bound transition), this feature is unlikely to arise from local interactions, supporting CME-driven auroral excitation on Jupiter.

2606.20350 2026-06-19 astro-ph.SR 新提交

V7995 Sgr: A New FU Orionis Accretion Outburst Near NGC 6589/6590

V7995 Sgr: 靠近 NGC 6589/6590 的一次新 FU Orionis 型吸积爆发

Lynne A. Hillenbrand (1), Kishalay De (2,3) Adolfo S. Carvalho (4), Dan Stern (1), Evan Portnoi (1), Nicholas Earley (1) ((1) California Institute of Technology, (2) Columbia University (3) Flatiron Institute, (4) Harvard University)

AI总结 本文报告了 V7995 Sgr 在 2024 年底达到峰值亮度的一次 FU Orionis 型爆发,基于多波段光变曲线和光谱观测,确认其由吸积盘驱动并伴有强风。

Comments submitted to ApJ Letters

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AI中文摘要

我们宣布了一次新的 FU Orionis 型爆发,该爆发在 2024 年底达到峰值亮度,此前在 $r$ 波段经历了 4.6 个月的陡峭光度上升,幅度为 -2.85 星等。这种在所有波长的快速增亮之前,红外波段在 4 年内经历了一次更平缓的上升。前身天体是一个未研究的年轻恒星天体,具有平谱型光谱能量分布和延伸星云。我们展示了覆盖光度低态、爆发和爆发后早期阶段的多波段光变曲线。光学成像显示延伸星云环境同时增亮。我们还展示了在推断的光度峰值后 1.5 年获得的后续光学/近红外光谱。光谱证实了 FU Ori 型爆发。爆发源显示出在吸积盘中形成的混合温度吸收光谱,并显示出几种具有蓝移吸收轮廓的谱线,这些谱线形成于强风中。

英文摘要

We announce a new FU Orionis type outburst that reached peak brightness in late 2024, following a steep 4.6 month photometric rise of -2.85 mag in the $r$ band. This rapid brightening at all wavelengths was preceeded in the infrared by a much shallower rise over 4 years. The progenitor object was an unstudied young stellar object having a flat-spectrum type spectral energy distribution, and extended nebulosity. We present multi-wavelength lightcurves covering the photometric low-state, the outburst, and early post-outburst epochs. Optical imaging shows a concurrent brightening of the extended nebular environment. We also present follow-up optical/near-infrared spectroscopy taken 1.5 years after the inferred photometric peak. The spectra confirm an FU Ori type outburst. The outburst source exhibits a mixed-temperature absorption spectrum, formed in an accretion disk, and it shows several line species with blueshifted absorption profiles that are formed in a strong wind.

2606.20337 2026-06-19 astro-ph.IM 新提交

Instruments for Focal Plane X-Ray Polarimetry in the Next Decade

未来十年焦平面X射线偏振测量仪器

Fabio Muleri, Stefano Cesare, Enrico Costa, Walter Cugno, Klaus Desch, Alessandro Di Marco, Sergio Fabiani, Riccardo Ferrazzoli, Markus Gruber, Daniel Heuchel, Saba Imtiaz, Jochen Kaminski, Dawoon Edwin Kim, Alessandro Lacerenza, Carlo Lefevre, Hemanth Manikantan, Vladislavs Plesanovs, John Rankin, Ajay Ratheesh, Alda Rubini, Paolo Soffitta

AI总结 针对IXPE任务能段有限的问题,提出基于多层镜和堆叠仪器的焦平面偏振计,将能量范围扩展至数十keV,提升灵敏度和降低背景,有望快速实现空间应用。

Comments Accepted for publication in "Particles" (MDPI) as reviewed proceedings of the conference "Advances in Space AstroParticle Physics: Frontier Technologies for Particle Measurements in Space, 2025 (ASAPP2025)", 12-16 May 2025, Sant Feliu de Guixols, Girona (ES). 15 pages, 9 figures, 1 table

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AI中文摘要

IXPE任务成功探测到来自不同类别天体的X射线偏振,开启了X射线天文学的新窗口。尽管IXPE已经解决了大量科学问题,但许多问题将受益于能够在较短时间内发射的新型仪器。本文介绍了一种焦平面偏振计的开发活动,其目标是将IXPE的能量范围扩展到数十keV,并具有更好的灵敏度和更低的背景。我们的设计基于多层镜和堆叠仪器,包括低能或中能成像光电偏振计以及有源康普顿偏振计。这种方法依赖于具有飞行经验的硬件,尽管仍在针对X射线偏振测量的特定应用进行开发,但它有潜力回答迫切的科学问题,并很快在空间应用的可行性方面具有竞争力。

英文摘要

The successful detection of X-ray polarization from many celestial sources belonging to different classes by the IXPE mission has opened a new window in X-ray astronomy. While an impressive number of scientific topics have already been addressed by IXPE, many of them would benefit from a new class of instrumentation that could be launched on a relatively short time scale. In this contribution, we present the development activities of a focal-plane polarimeter whose goal is to extend the energy range of IXPE up to tens of keV, with better sensitivity and lower background. Our design is based on the use of multilayer mirrors and stacked instrumentation, comprising either a low- or medium-energy imaging photoelectric polarimeter and an active Compton polarimeter. Such an approach relies on hardware with flight heritage and -- although still under development for the specific application in X-ray polarimetry -- it has the potential to answer compelling scientific questions and to soon become competitive from the point of view of feasibility for space applications.

2606.20335 2026-06-19 astro-ph.GA astro-ph.HE 新提交

A merger shock traced by radio arcs and ultra-long radio tails in galaxy cluster A2142

星系团A2142中由射电弧和超长射电尾迹示踪的并合激波

Chong Ge, Ming Sun, Chris Nolting, Fabio Gastaldello, Dominique Eckert

AI总结 利用XMM-Newton在A2142西北侧探测到马赫数约1.3的并合激波,该激波与射电弧空间重合,并导致超长射电尾迹(>500 kpc),为并合激波示踪提供了新方法。

Comments 13 pages, 5 figures, submitted to ApJ

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AI中文摘要

Abell 2142(A2142)是一个正在经历复杂并合的大质量邻近星系团。它沿西北-东南方向呈现拉长的X射线形态,并拥有四个已知的冷锋。利用XMM-Newton观测,我们在星系团西北侧探测到一个马赫数为$M \sim 1.3$的并合激波。观测到的激波前沿和四个冷锋可以通过大碰撞参数的偏轴并合数值模拟重现,该并合赋予子团核心和大尺度环境气体显著的角动量,从而引发晃动。在投影中,激波前沿与在显著头尾射电星系T1和T2后方观测到的弧形射电纤维空间重合。我们将这些射电弧解释为部分涡环结构(类似于“烟圈”),由并合激波与射电星系的低密度茧相互作用产生。激波剥离并卷曲喷流茧形成环形涡旋,正如最近的磁流体动力学模拟所预测。我们进一步证明,并合激波可以通过重新加速老化的相对论性电子以及通过激波后风拉伸尾迹等离子体,显著拉长射电尾迹。这一过程为该并合团及其他并合团中观测到的$>$500 kpc尾迹提供了自然解释。我们的发现确立了射电弧和超长射电尾迹作为星系团中并合激波的独立互补示踪物。我们的结果表明,并合激波可以重塑星系团的热和非热成分,并且尾迹射电星系可作为团内介质天气的灵敏探针。

英文摘要

Abell 2142 (A2142) is a massive, nearby galaxy cluster undergoing a complex merger. It exhibits an elongated X-ray morphology along the northwest-southeast axis and hosts four known cold fronts. Using XMM-Newton observations, we detect a merger shock on the northwest side of the cluster with a Mach number of $M \sim 1.3$. The observed shock front and four cold fronts can be reproduced by numerical simulations of an off-axis merger with a large impact parameter, which imparts significant angular momentum to induce the sloshing of the subcluster core and large-scale ambient gas. In projection, the shock front is spatially coincident with arc-shaped radio filaments observed behind the prominent head-tail radio galaxies T1 and T2. We interpret these radio arcs as partial vortex ring structures (resembling ``smoke rings'') produced by the interaction of the merger shock with the low-density cocoons of radio galaxies. The shock strips and rolls the jet cocoon into a toroidal vortex, as predicted by recent magnetohydrodynamic simulations. We further demonstrate that the merger shock can significantly elongate the radio tails by re-accelerating aged relativistic electrons and stretching the tail plasma via the post-shock wind. This process provides a natural explanation for the $>$500 kpc tail observed in this and other merging clusters. Our findings establish radio arcs and ultra-long radio tails as independent, complementary tracers of merger shocks in galaxy clusters. Our results demonstrate that merger shocks can reshape both the thermal and non-thermal components of galaxy clusters, and that tailed radio galaxies serve as sensitive probes of intracluster medium weather.

2606.20308 2026-06-19 astro-ph.HE 新提交

Evidence for candidate X-ray pulsations from the ultraluminous X-ray source NGC 7456 ULX-1

来自超亮X射线源NGC 7456 ULX-1的候选X射线脉冲信号证据

Yuanle Yao, Xiang-Dong Li, Xiao-Jie Xu (NJU)

AI总结 利用XMM-Newton数据,通过加速搜索、Z²统计和轨道解调分析,在NGC 7456 ULX-1中发现约0.22 Hz的候选脉冲信号,推测其可能包含吸积中子星。

Comments 12 pages, 7 figures, to be published in ApJ

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AI中文摘要

我们报告了来自NGC 7456 ULX-1(一个先前已识别的超亮X射线源,ULX)的约0.22 Hz候选脉冲信号的证据。该信号在2023年XMM-Newton观测中通过独立计时技术(包括加速搜索、$Z^2_n$统计和旨在恢复双星运动下相位相干的轨道解调分析)被识别。候选脉冲频率在观测期间的漂移表明由吸积扭矩驱动的快速自旋演化。我们进一步估计表面偶极磁场强度为$B\sim 10^{12}-10^{14}$ G。这些结果提供了NGC 7456 ULX-1可能包含一个吸积中子星的证据,尽管需要独立数据集或额外观测进行确认。

英文摘要

We report evidence for a candidate pulsational signal at $\sim0.22$~Hz from NGC7456 ULX-1, a previously identified ultraluminous X-ray source (ULX). The signal is identified in the 2023 XMM-Newton observation using independent timing techniques including accelerated searches, $Z^2_n$ statistics, and an orbital-demodulation analysis designed to restore phase coherence in the presence of binary motion. The candidate pulsation frequency drift within the observation suggests rapid spin evolution driven by accretion torque. We further estimate the surface dipole magnetic field strength to be $B\sim 10^{12}-10^{14}$ G. These results provide evidence that NGC7456 ULX-1 may host an accreting neutron star, although confirmation with independent datasets or additional observations is required.

2606.20305 2026-06-19 astro-ph.SR 新提交

Intermittent turbulent fluctuations in solar coronal mass ejections

太阳日冕物质抛射中的间歇性湍流波动

Apurva Bhagat, Sumit Tambe, Debesh Bhattacharjee, Prasad Subramanian

AI总结 利用125个日冕物质抛射的近地观测数据,发现最强湍流斑强度和出现率是CME前沿开始的可靠指标,且湍流斑可增强质子加热。

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AI中文摘要

已知局部高强度波动区域是流体和等离子体湍流中间歇性的标志。我们利用近地{\em 原位}航天器观测的125个太阳日冕物质抛射(CME)样本研究了此类湍流斑。统计结果表明,最强湍流斑的强度和湍流斑出现率是CME事件前沿开始的可靠指标。我们的发现还表明,湍流斑可能是质子加热增强的场所。本研究结果可增进我们对无碰撞等离子体湍流中间歇性的理解,并改进CME/鞘层驱动的空间天气影响预测模型。

英文摘要

Localised regions of high intensity fluctuations are known to be signatures of intermittency in fluid and plasma turbulence. We investigate such turbulent spots using near-Earth {\em in-situ} spacecraft observations of a sample of 125 solar coronal mass ejections (CMEs). We present statistical results which suggest that the intensity of the strongest turbulent spot and the turbulent spot occurrence rate are reliable indicators of the onset of the leading part of the CME event. Our findings also suggest that turbulent spots can be sites of enhanced proton heating. The findings of this study can enhance our understanding of intermittence in collisionless plasma turbulence and can improve CME/sheath-driven space weather impact prediction models.

2606.20265 2026-06-19 astro-ph.GA astro-ph.IM 新提交

UCLCHEM 4.0: An open source gas-grain astrochemistry simulation framework

UCLCHEM 4.0:开源气体-颗粒天体化学模拟框架

Gijs Vermariën, Serena Viti, Tobias M. Dijkhuis, Le Ngoc Tram, Marcus Keil, Katarzyna M. Dutkowska, Felix D. Priestley

AI总结 介绍UCLCHEM 4.0开源天体化学模拟框架,它通过求解化学反应网络模拟星际介质中分子形成与破坏,支持从星系尺度到原行星盘尺度的物理化学过程。

Comments Submitted to RAS Techniques and Instruments

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AI中文摘要

天体化学建模是理解星际介质稠密气体中分子形成与破坏的关键工具,正如现代观测设施所观测到的那样。UCLCHEM是一个全面的天体化学建模框架,可以模拟从星系外到原行星盘尺度的星际介质。该框架由一个核心程序组成,该程序求解随时间变化的化学反应网络。化学过程包括气体和冰粒化学的描述以及两者之间的相互作用。物理建模包括用于模拟云坍缩、原恒星核和激波的参数化,以及提供用户自定义输入的能力。本文概述了UCLCHEM中包含的物理和化学过程,以及求解器程序和编程接口的内部工作原理。

英文摘要

Astrochemical modeling is a key tool for the understanding of the formation and destruction of molecules in the dense gas of the interstellar medium, as observed by modern day observational facilities. UCLCHEM is a comprehensive astrochemical modeling framework that can model the interstellar medium ranging from extra-galactic to protoplanetary disks scales. The framework consists of a core routine that solves chemical reaction networks as a function of time. The chemistry includes a description of gas and ice grain chemistry and the interactions between the two. The physical modeling includes parametrizations for modelling cloud collapse, protostellar cores and shocks as well as the ability to provide user defined inputs. This manuscript provides an overview of the physics and chemistry included in UCLCHEM, as well as the inner workings of the solver routine and the programming interface.

2606.20249 2026-06-19 astro-ph.EP physics.geo-ph 新提交

Geophysical and atmospheric implications of $f$O$_{2}$-dependent melting on rocky exoplanets

岩石系外行星上依赖于氧逸度的熔融对地球物理和大气的影响

Mariana Sastre, Tim Lichtenberg, Laurent Soucasse, Dan J. Bower, Harrison Nicholls, Inga Kamp

AI总结 通过耦合内部-大气框架PROTEUS,量化了氧逸度依赖的熔融曲线对岩石系外行星热结构、熔融分数和流变演化的非线性影响,揭示了挥发分库存和表面氧逸度对热状态的主要调控作用。

Comments 15 pages, 8 figures; accepted for publication in Astronomy & Astrophysics

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AI中文摘要

长期存在的岩浆海洋的地球化学演化受到熔融地幔与大气之间挥发性交换的强烈调控。对于处于失控温室极限内的行星,这种耦合演化可以持续数十亿年。然而,大多数现有研究假设类地(氧化)条件,并忽略了氧化还原状态对熔体热力学和挥发性释放的影响。我们量化了在耦合内部-大气框架PROTEUS中实现的实验推导的、氧逸度依赖的熔融曲线如何传播到岩石系外行星内部的热结构、熔融分数和流变演化,并将其应用于短周期超级地球GJ 1132 b。我们发现熔融曲线的变化导致强烈的非线性热响应。在贫挥发分系统中,相对于氧化和类地情况,还原熔融曲线促进了早期深部地幔结晶,有利于由温室效应维持的晚期表面岩浆海洋,而氧化熔融曲线则维持较高的熔融分数和垂直延伸的岩浆海洋。还原地幔产生大量的H$_2$-CO富集大气;氧化地幔则倾向于较薄的H$_2$O-CO$_2$包层。在富挥发分系统中,内部在高熔融分数下达到辐射平衡,维持稳态全球岩浆海洋,其中熔融曲线的变化不会显著影响凝固时间。这表明了层次控制:挥发分库存和表面氧逸度作为热状态的主要调节者,而氧逸度依赖的熔融关系提供次级调制。这些对比鲜明的状态产生不同的大气组成和形成时间尺度,为近距离岩石系外行星提供了可测试的光谱预测,这些预测可通过即将进行的JWST观测进行评估。

英文摘要

The geochemical evolution of long-lived magma oceans is strongly regulated by volatile exchange between the molten mantle and the atmosphere. For planets inside the runaway-greenhouse limit, this coupled evolution can persist for billions of years. However, most existing studies assume Earth-like (oxidized) conditions and neglect the influence of redox state on melt thermodynamics and volatile release. We quantified how experimentally derived, oxygen-fugacity-dependent melting curves implemented within the coupled interior-atmosphere framework PROTEUS propagate into the thermal structure, melt fraction, and rheological evolution of rocky exoplanet interiors, applying this to the short-period super-Earth GJ 1132 b. We found strongly non-linear thermal responses to variations in melting curves. In volatile-poor systems, reduced melting curves promote earlier deep-mantle crystallisation relative to oxidised and Earth-like cases, favouring late-stage surface magma oceans sustained by greenhouse warming, while oxidized melting curves maintain higher melt fractions and a vertically extended magma ocean. Reduced mantles produce massive H$_2$-CO-rich atmospheres; oxidized mantles favour thinner H$_2$O-CO$_2$ envelopes. In volatile-rich systems, the interior reaches radiative equilibrium at high melt fractions, sustaining a steady-state global magma ocean in which melting curve variations do not significantly influence solidification timing. This indicates a hierarchical control: volatile inventory and surface oxygen fugacity act as the primary regulators of thermal state, while oxygen-fugacity-dependent melting relations provide a secondary modulation. These contrasting regimes produce distinct atmospheric compositions and formation timescales, offering testable spectral predictions for close-in rocky exoplanets evaluable with forthcoming JWST observations.

2606.20224 2026-06-19 astro-ph.EP 新提交

TOI-2147 b and TOI-6019 b: Two eccentric warm Jupiters detected and characterized with TESS and MaHPS

TOI-2147 b 和 TOI-6019 b:利用 TESS 和 MaHPS 探测并表征的两颗偏心暖木星

Luis Thomas, Louise D. Nielsen, Hanna Kellermann, Bibiana Prinoth, Yutong Liu, Elif Zeynep Özden, Arno Riffeser, Claus Gössl, Frank Grupp, Jerome de Leon, Karen A. Collins, Allyson Bieryla, Lorena Acuña-Aguirre, Keith Baka, Malte Busmann, David R. Ciardi, Catherine A. Clark, Juliana Ehrhardt, Mark E. Everett, Akihiko Fukui, Jan-Vincent Harre, Keisuke Isogai, Felipe Murgas, Norio Narita, Enric Palle, Hannu Parviainen, Jan-Niklas Pippert, Christoph Ries, Boris S. Safonov, Thomas Schäfer, Michael Schmidt, Richard P. Schwarz, Laura Schöller, Gregorg Srdoc, Ivan A. Strakhov, Suzanne Taylor, Raphael Zöller

AI总结 利用TESS测光、地面多波段测光、高角分辨率成像和MaHPS高精度径向速度数据,确认了两颗偏心暖木星TOI-2147 b和TOI-6019 b,并表征了其轨道参数、物理性质及内部结构,表明潮汐加热导致半径膨胀,支持高偏心迁移起源。

Comments 14 pages, 9 figures. Accepted for publication in A&A

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AI中文摘要

轨道周期在10到200天之间的木星大小系外行星(WJs)群体表现出广泛的轨道偏心率和系统架构,表明其形成和迁移路径的多样性。在这项工作中,我们报告了两颗新的偏心WJs——TOI-2147 b和TOI-6019 b的探测和表征,它们最初由凌星系外行星巡天卫星(TESS)识别为行星候选体。我们将TESS测光与地面后续观测相结合,包括来自LCOGT和MuSCAT2的多波段测光、高角分辨率散斑成像以及来自高分辨率Manfred Hirt Planet Finder Spectrograph(MaHPS)的高精度径向速度测量。利用这些数据,我们确认了这两个候选体的行星性质。TOI-2147 b的半径为$10.5 \pm 0.3\,\mathrm{R}_\oplus$,质量为$116 \pm 22\,\mathrm{M}_\oplus$。它绕一颗略贫金属($\mathrm{[Fe/H]} = -0.29^{+0.07}_{-0.08}$)的G型主星运行,轨道偏心率为$e = 0.29 \pm 0.07$,周期为26.2天。TOI-6019 b的半径为$12.3 \pm 0.3\,\mathrm{R}_\oplus$,质量为$149 \pm 15\,\mathrm{M}_\oplus$。它绕一颗略演化、太阳金属丰度的G型亚巨星运行,周期为14.5天,轨道显著偏心($e = 0.48^{+0.05}_{-0.04}$)。两颗行星的体密度均低于木星,表明半径略有膨胀,通过GASTLI进行内部结构建模表明,非零偏心引起的潮汐加热可能导致了这种膨胀,并且不支持大气中大量金属富集。在径向速度时间序列或凌星时间变化中未检测到来自额外伴星的显著信号。结合较高的偏心率,这支持两个系统的高偏心迁移起源。

英文摘要

The population of Jupiter-sized exoplanets with orbital periods between 10 and 200 days (WJs) exhibits a broad range of orbital eccentricities and system architectures, suggesting a diversity of formation and migration pathways. In this work, we report the detection and characterization of two new eccentric WJs, TOI-2147 b and TOI-6019 b, initially identified as planet candidates by the Transiting Exoplanet Survey Satellite (TESS). We combined TESS photometry with ground-based follow-up observations, including multiband photometry from LCOGT and MuSCAT2, high-angular-resolution speckle imaging, and high-precision radial velocity measurements from the high-resolution Manfred Hirt Planet Finder Spectrograph (MaHPS). Using these data, we were able to confirm the planetary nature of both candidates. TOI-2147 b has a radius of $10.5 \pm 0.3\,\mathrm{R}_\oplus$ and a mass of $116 \pm 22\,\mathrm{M}_\oplus$. It orbits its slightly metal-poor ($\mathrm{[Fe/H]} = -0.29^{+0.07}_{-0.08}$) G-type host star on an eccentric orbit ($e = 0.29 \pm 0.07$) with a period of 26.2 days. TOI-6019 b has a radius of $12.3 \pm 0.3\,\mathrm{R}_\oplus$ and a mass of $149 \pm 15\,\mathrm{M}_\oplus$. It orbits a slightly evolved, solar-metallicity G-type sub-giant with a period of 14.5 days on a significantly eccentric orbit ($e = 0.48^{+0.05}_{-0.04}$). Both planets have bulk densities below that of Jupiter, indicating mildly inflated radii, with interior structure modeling using GASTLI. This suggests that tidal heating from the nonzero eccentricities likely contributes to this inflation and disfavors large atmospheric metal enrichment. No significant signals from additional companions were detected in the radial velocity time series or transit timing variations. Together with the elevated eccentricities, this is consistent with a high-eccentricity migration origin for both systems.

2606.20204 2026-06-19 astro-ph.SR 新提交

Solar Wind Dependence on Source Distance from the Open-Closed Boundary

太阳风对源区距开闭边界距离的依赖性

Chloe P. Wilkins, David I. Pontin, Anthony R. Yeates, Nicholeen M. Viall, Spiro K. Antiochos

AI总结 利用两种日冕磁场模型,发现太阳风成分强烈依赖于源磁通量距开闭边界的距离,增强的电荷态比、元素丰度和成分变化集中在边界周围超米粒尺度区域,支持互换磁重联在慢太阳风释放中的关键作用。

Comments 17 pages, 11 figures

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AI中文摘要

慢太阳风的起源和变异性仍然是太阳物理学中的一个未解问题,但被认为与太阳开闭磁通边界(OCB)处的动力学密切相关。OCB处的互换磁重联被认为是将闭场等离子体释放到日球层的一种机制,但将太阳风成分与OCB拓扑联系起来的观测证据仍然有限。我们利用两种日冕磁场模型——势场源表面模型和磁摩擦模型,将尤利西斯号在10年期间的原地太阳风测量与其源区的磁拓扑联系起来。我们发现太阳风成分强烈依赖于源磁通量距OCB的距离。增强的离子电荷态比、元素丰度和成分变化集中在OCB周围的超米粒尺度区域(约25 Mm),与互换磁重联的空间尺度一致。这种变异性随着距边界距离的增加而系统性地减小,冕洞风表现出更均匀的快风特征。我们还发现,从靠近OCB的区域涌出的太阳风成分受到邻近闭磁场强度的影响,较强的磁场优先与慢风特性相关。这些结果表明,慢风的成分强烈受OCB磁拓扑的支配,为互换重联在慢太阳风释放和结构中起关键作用提供了令人信服的证据。

英文摘要

The origin and variability of the slow solar wind remains an open question in solar physics, but is thought to be closely linked to dynamics at the Sun's open-closed magnetic flux boundary (OCB). Interchange magnetic reconnection at the OCB has been proposed as a mechanism for releasing closed-field plasma into the heliosphere, but observational evidence linking solar wind composition to OCB topology remains limited. We relate in situ solar wind measurements by Ulysses over a 10-year period to the magnetic topology of their source regions using two coronal magnetic field models: a potential field source surface model and a magnetofrictional model. We find a strong dependence of solar wind composition on the distance of the source magnetic flux from the OCB. Enhanced ion charge-state ratios, elemental abundances, and compositional variability are found to be concentrated within a supergranular-scale region (around 25 Mm) surrounding the OCB, consistent with the spatial scales of interchange magnetic reconnection. This variability decreases systematically with increasing distance from the boundary, with coronal hole wind exhibiting more uniform fast-wind signatures. We also find that the composition of solar wind emerging from regions close to the OCB is influenced by the strength of neighbouring closed magnetic fields, with stronger fields preferentially associated with slow-wind properties. These results indicate that the composition of the slow wind is strongly governed by the magnetic topology of the OCB, providing compelling evidence that interchange reconnection plays a crucial role in slow solar wind release and structure.

2606.20201 2026-06-19 astro-ph.HE 新提交

Kick bimodality of neutron stars and mode dependence of their parameters

中子星的踢动双峰性及其参数的模式依赖性

Anton D. Lazarev, Sergei B. Popov

AI总结 通过分析约200颗正常孤立射电脉冲星,发现约30%属于低速踢动模式,并比较了两类脉冲星的参数差异,发现磁场分布存在显著差异。

Comments 13 pages, 7 figures. Submitted to Ap&SS

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AI中文摘要

观测数据的分析和理论建模支持中子星诞生速度踢动的双峰分布。对于约200颗自旋和运动学参数确定正常的孤立射电脉冲星,我们确定它们属于分布的低速或高速模式。我们的结果表明,约30%属于低速模式。然后我们分析了两组脉冲星性质的差异。对于一些参数(特征年龄、距离和射电光度),我们看到两种模式之间存在明显差异。然而,对于这些量,这很容易归因于选择偏差。对于那些不受强烈选择影响的参数,如脉冲宽度,我们没有观察到任何差异。有趣的是,我们检测到两种模式之间的磁场分布存在显著差异。与高速模式相比,低速模式中的低场脉冲星($B\lesssim 10^{12}$~G)数量过多。在低场($\lesssim 10^{11}$~G)脉冲星中,我们没有识别出任何来自踢动分布高速模式的天体。这种差异的起源尚不清楚,我们讨论了几种可能性。

英文摘要

Analysis of observational data and theoretical modeling favors a bimodal distribution of the natal velocity kick of neutron stars. For $\sim200$ normal isolated radio pulsars with well-determined spin and kinematic parameters, we determine if they belong to the low- or high-velocity mode of the distribution. Our results demonstrate that about $30\%$ belong to the low-velocity mode. We then analyze the differences in the properties of the two sets of pulsars. For some parameters (characteristic ages, distances, and radio luminosities), we see a clear difference between the two modes. However, for these quantities, it can be easily attributed to selection bias. For those parameters that are not a subject of strong selection, such as pulse width, we do not observe any difference. Interestingly, we detect a significant difference in the magnetic field distribution between the two modes. Lower field pulsars ($B\lesssim 10^{12}$~G) are overabundant among objects from the low-velocity mode in comparison to the high-velocity one. Among pulsars with low field ($\lesssim 10^{11}$~G), we do not identify any objects from the high-velocity mode of the kick distribution. The origin of this discrepancy is not clear, and we discuss several possibilities.

2606.20200 2026-06-19 astro-ph.GA 新提交

Abundances of CNO in candidate young metal-poor stars

候选年轻贫金属星中CNO的丰度

Piercarlo Bonifacio (LIRA), Elisabetta Caffau (LIRA), Luca Sbordone (ESO), Lorenzo Monaco (UNAB), Linda Lombardo (OAT), Rosine Lallement (LIRA), Monique Spite (LIRA), Patrick Francois (LIRA,UPJV), Alessio Mucciarelli (UNIBO)

AI总结 通过分析五颗看似年轻的演化星的CNO丰度,区分真正年轻星与因吸积而再生的星,发现低[C/O]比与演化状态一致,不支持吸积。

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AI中文摘要

在这项工作中,我们研究了五颗看似年轻的演化星中的CNO丰度,旨在区分真正年轻的星和通过从另一颗星吸积质量而再生的星。预期吸积质量的星会显示低C和O以及非常低的[C/O]比,正如球状星团47 Tuc中的一些星所显示的那样,这些星被认为经历了质量转移。在我们的样本中,观测到的低[C/O]比似乎与其演化状态兼容。因此,没有迹象表明这些星吸积了质量。

英文摘要

In this contribution we investigate the CNO abundances in five apparently young evolved stars, with the aim of discriminating between truly young stars and stars that were rejuvenated by accreting mass from another star. Stars that have accreted mass are expected to show low C and O and a very low [C/O] ratio, as displayed by some stars in the Globular Cluster 47 Tuc, that are believed to have undergone mass-transfer. In our sample the low [C/O] ratios observed appear to be compatible with their evolutionary status. There is thus no indication for these stars having accreted mass.__

2606.20194 2026-06-19 astro-ph.IM 新提交

MOSAIC at ELT: Design and First Performance Results of Novel Robotic Optical-Relay Positioners

MOSAIC在ELT:新型机器人光学中继定位器的设计与首次性能结果

Maxime Rombach, Markus Thurneysen, Lucas Ortolani, Jurgen Schmoll, Diane Chapuis, Malak Galal, Sebastien Pernecker, Cassio Berni, Ojonugwa Adukwu, Fabio Fialho, Michaela Hirschmann, Jean-Paul Kneib

AI总结 本文介绍了为极大望远镜ELT设计的MOSAIC多目标光谱仪中约300个机器人定位器的创新设计,包括中继镜、自适应指向和独立大气色散校正,并展示了初步原型和性能结果。

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AI中文摘要

极大望远镜(ELT)是迄今为止在建的最具雄心的地基望远镜。MOSAIC是一个多目标光谱仪(MOS),旨在充分利用世界上最大的望远镜。其核心是约300个机器人定位器,将从ELT焦面拾取天光,馈送至其近红外(NIR)和可见光(VIS)光谱仪。ELT的巨大规模给MOSAIC定位器带来了三个主要挑战:(1)焦面上的光束无法像其他MOS仪器那样聚焦到单根光纤中,因此设计采用中继镜巡视视场,并将子场重新成像到位于ELT焦面后方600 mm处的两个固定光纤束上;(2)定位器需要适应本地远心性,即必须指向距焦面37.868 m处的ELT光瞳中心;(3)覆盖ELT整个焦面的大气色散校正器(ADC)按此规模无法建造,因此每个定位器需要自己的ADC。EPFL负责设计并监督定位器的批量制造。本文旨在介绍其初始设计和原型。

英文摘要

The Extremely Large Telescope (ELT) is, to date, the most ambitious ground-based telescope under construction. MOSAIC is a multi-objects spectrograph (MOS) that aims to make full use of the largest telescope in the world. At its heart, about 300 robotic positioners will pick-off skylight from the focal surface of the ELT to feed it to its Near Infrared (NIR) and visible (VIS) spectrographs. The gigantic scale of the ELT presents three main challenges for MOSAIC positioners: (1) the light beams on the focal surface cannot be focused in a single fiber, similarly to other MOS instruments, involving a design with relay mirrors patrolling the field of view, and reimaging the sub-field on 2 fixed fiber bundles located 600 mm behind the ELT focal plane (2) The positioner needs to adapt to the local telecentricity, which means it has to point at the ELT pupil center located 37.868 m away from the focal plane (3) The Atmospheric Dispersion Corrector (ADC) needed to cover the whole focal surface of the ELT is impossible to build to this scale; hence each positioner needs its own ADC. EPFL is responsible for designing and supervising the mass manufacturing of the positioners. This paper aims to present its initial design and prototypes.