Astrophysics and Space Science最新文献_第4页

Constraining hydrodynamic model of nearby type IIP SN 2023ixf 邻近型IIP SN 2023ixf约束水动力模型

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-14 DOI: 10.1007/s10509-026-04619-8

V. P. Utrobin, N. N. Chugai

{"title":"Constraining hydrodynamic model of nearby type IIP SN 2023ixf","authors":"V. P. Utrobin, N. N. Chugai","doi":"10.1007/s10509-026-04619-8","DOIUrl":"10.1007/s10509-026-04619-8","url":null,"abstract":"<div><p>Despite proximity of SN 2023ixf and a wealth of observational data, the released hydrodynamic models leave too broad range of the derived explosion energy and the ejected mass. We revisit the hydrodynamic modeling based on a broader set of observables than have been previously used. Among those of top priority is the early maximum ejecta velocity that is crucial in removing parameter degeneracy. The inferred parameters of SN 2023ixf are the explosion energy of <span>(2.8times 10^{51})</span> erg, ejecta mass of 13.2 <span>(M_{odot })</span>, presupernova radius of 1540 <span>(R_{odot })</span>, and <sup>56</sup>Ni mass of 0.07 <span>(M_{odot })</span>. The circumstellar matter is composed by the dense circumstellar shell with the mass of 0.01 <span>(M_{odot })</span> and radius of <span>(5times 10^{14}text{ cm})</span>, as well as the external rarefied wind. Both circumstellar components are consistent with the early H<span>(alpha )</span> broad wings caused by the Thomson scattering and the intrinsic column density provided by X-ray data. Based on the radiation hydrodynamics we, for the first time, simulate the SN 2023ixf phenomenon from the explosion to the emergence of the hard X-ray radiation.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751808","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

The two-stream instability generation around Moon: effect of interplanetary magnetic field during solar wind - lunar plasma interaction 月球周围双流不稳定性的产生：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 : 2026-08-14 DOI: 10.1007/s10509-026-04620-1

Vipin K. Yadav, Abhinav Singh, Rajneesh Kumar

{"title":"The two-stream instability generation around Moon: effect of interplanetary magnetic field during solar wind - lunar plasma interaction","authors":"Vipin K. Yadav, Abhinav Singh, Rajneesh Kumar","doi":"10.1007/s10509-026-04620-1","DOIUrl":"10.1007/s10509-026-04620-1","url":null,"abstract":"<div><p>The relative motion of two interpenetrating streams of charged particles usually leads to the generation of two-stream instability (TSI) and eventually result in the onset of non-linear plasma processes such as the turbulence or the plasma waves. A natural example of such an event is the solar wind interaction with the lunar electron plasma where the interplanetary magnetic field (IMF) is embedded within the solar wind. The inclusion of IMF in the solar wind – lunar plasma interaction modifies the dispersion relation of the TSI and an angular cyclotron frequency term appears in the denominator of the leading term and hence leads to the change in the parameters such as the instability growth rate as now it depends on the solar wind electron velocity, solar wind and the lunar electron plasma density, and the IMF magnitude. It is observed that the growth rate increases fast with the increase in the magnetic field initially but the increase slows down on further increasing the magnetic field thereby smoothening the top. From the particle-in-cell (PIC) simulations, it is observed that during the solar wind IMF interaction with lunar plasma, the non-energetic background electrons make a shield around the solar wind electrons in the vortices formed. It is further observed that those lunar electrons which are not participating either in the vortices formation or in the shielding of solar wind electrons, start moving in the direction of the incoming solar wind. These observations indicate this interaction is capable in getting converted into a non-linear physical process in the lunar plasma environment.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751807","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

The B-index as a diagnostic of cool stars: assessing metallicity dependence of TiO absorption in the visible spectrum b指数作为冷恒星的诊断：评估可见光光谱中TiO吸收对金属丰度的依赖

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-14 DOI: 10.1007/s10509-026-04621-0

Fatemeh Azizi, Mohammad Taghi Mirtorabi, Zahra Mohammadian

{"title":"The B-index as a diagnostic of cool stars: assessing metallicity dependence of TiO absorption in the visible spectrum","authors":"Fatemeh Azizi, Mohammad Taghi Mirtorabi, Zahra Mohammadian","doi":"10.1007/s10509-026-04621-0","DOIUrl":"10.1007/s10509-026-04621-0","url":null,"abstract":"<div><p>Molecular absorption features constitute essential diagnostics of late-type stellar atmospheres, with titanium oxide (TiO) bands serving as sensitive tracers of effective temperature and magnetic activity. While near-infrared TiO indices are well established, visible-band diagnostics provide complementary constraints for stellar classification and parameter estimation. This study investigates the metallicity dependence of the B-index, a TiO absorption measure centered at 567 nm, through synthetic spectra generated with ATLAS9 and high-resolution observations from the HARPS spectrograph. The synthetic grid spans effective temperatures between 3500–4000 K and metallicities from <span>(mbox{[Fe/H]} = -4)</span> to +0.2, while the observational sample comprises 23 MK spectral types stars with effective temperatures between 3500–4000 K. Both theoretical and empirical analyses demonstrate that the B-index exhibits negligible sensitivity to stellar metallicity, with only marginal correlations detected. Therefore, there is no requirement to include this feature in the calculation of the B-index. The B-index’s low sensitivity to metallicity reinforces its utility as an effective tool for spectral classification, stellar atmosphere modeling, and the study of magnetically active stars.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751804","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

Ultracool and brown dwarf candidates identified via CatWISE-2MASS-Gaia DR3 通过CatWISE-2MASS-Gaia DR3发现的超冷矮星和褐矮星候选者

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-10 DOI: 10.1007/s10509-026-04616-x

Daniel Majaess, Dante Minniti, Matias Gomez, Roberto K. Saito, Maria G. Navarro

引用次数: 0

A viable dynamic dark energy model with parametrized equation of state 具有参数化状态方程的可行动态暗能量模型

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-10 DOI: 10.1007/s10509-026-04615-y

C. Sivakumar, A. Abirami, C. Athuldev

{"title":"A viable dynamic dark energy model with parametrized equation of state","authors":"C. Sivakumar, A. Abirami, C. Athuldev","doi":"10.1007/s10509-026-04615-y","DOIUrl":"10.1007/s10509-026-04615-y","url":null,"abstract":"<div><p>A novel and analytically simplifiable parametrization for the equation of state (EoS) of the dark energy, which elegantly captures the universe’s transition from a decelerated matter-dominated era (<span>(omega approx 0)</span> at high redshift) to the current phase of accelerated expansion (<span>(omega rightarrow -1)</span> as <span>(zrightarrow 0)</span>) is introduced. The primary focus lies in a comprehensive theoretical formulation of this model within the standard Friedmann framework, deriving key cosmological parameters and exploring the model’s behaviour across cosmic history. This parametrization provides a smooth and physically consistent evolution of the EoS, naturally reproducing the observed transition from deceleration to acceleration around <span>(zapprox 0.5)</span>, without invoking exotic fields or higher-order corrections. In contrast to conventional parametrized dark energy models such as Chevallier-Polarski-Linder (CPL), Jassal-Bagla-Padmanabhan (JBP), and Barboza-Alcaniz (BA) expansions, the present model stands out for its simplicity, stability, and freedom from divergences across the full redshift range. Using observed Hubble data, best fit values of model parameters are obtained and are consistent with current cosmological parameter values. The state-finder diagnostics and a phase space analysis well support the dynamic dark energy parametrization.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751128","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

Chemical evolution of galaxies: past, present and future 星系的化学演化：过去、现在和未来

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-08-05 DOI: 10.1007/s10509-026-04614-z

Francesca Matteucci

{"title":"Chemical evolution of galaxies: past, present and future","authors":"Francesca Matteucci","doi":"10.1007/s10509-026-04614-z","DOIUrl":"10.1007/s10509-026-04614-z","url":null,"abstract":"<div><p>In this paper I will describe the basic principles of chemical evolution of galaxies, its main ingredients and uncertainties. By means of chemical evolution we can perform the so-called galactic archaeology, which consists in reconstructing the history of star formation of galaxies and in particular of the Milky Way, starting from the observed stellar and gas abundances. Galactic archaeology is a powerful tool to predict also the behavior of galaxies at high redshift. In particular, we adopt the “time-delay model” which is a way of interpreting the [X/Fe] vs. [Fe/H] relations (X is the abundance of a specific chemical element) in terms of different timescales of the stellar progenitors of the chemical elements relative to Fe, which is the indicator of “metallicity”. I will then describe how we can reconstruct the star formation histories of galaxies of different morphological type (spirals, ellipticals) starting from the available observations. Particular attention will be paid to the study of the Milky Way which is the best studied galaxy at the moment. I will start describing the first chemical evolution models and then the most recent ones, the main difference between the old and new models being the observational data to compare with. Finally, I will foresee which could be the future improvements to chemical models and what constraints can we derive to better understand galaxy evolution.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 8","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10509-026-04614-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148695322","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

Cosmological dynamics of (f(R,G)) gravity with dark sector coupling and observational analysis 具有暗扇区耦合的(f(R,G))引力宇宙学动力学与观测分析

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-07-30 DOI: 10.1007/s10509-026-04613-0

Mohit Thakre, Praveen Kumar Dhankar, Albert Munyeshyaka, Safiqul Islam

引用次数: 0

Distance estimates to five bok globules using Gaia DR3 parallaxes and near-infrared photometry: validation with 3D dust maps 使用Gaia DR3视差和近红外测光法估计5个bok球状体的距离：用3D尘埃图验证

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-07-29 DOI: 10.1007/s10509-026-04608-x

Rajat Subhra Paul, Himadri Sekhar Das

引用次数: 0

Observational implications of varying-(G) in nonlinear electrodynamics cosmology 变化- (G)在非线性电动力学宇宙学中的观测意义

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-07-29 DOI: 10.1007/s10509-026-04612-1

Sajal Mandal, Rakesh Raushan, Raghavendra Chaubey

{"title":"Observational implications of varying-(G) in nonlinear electrodynamics cosmology","authors":"Sajal Mandal, Rakesh Raushan, Raghavendra Chaubey","doi":"10.1007/s10509-026-04612-1","DOIUrl":"10.1007/s10509-026-04612-1","url":null,"abstract":"<div><p>This study investigates a cosmological model driven by nonlinear electrodynamics (NLE) with a varying gravitational constant <span>(G)</span>. The aim is to explore the current accelerated evolution of the universe influenced by a magnetic field within this NLE-driven framework. A homogeneous and isotropic cosmological model with flat spatial sections is considered. NLE fields with varying <span>(G)</span> are treated as the source of gravitation. Model parameters are constrained using the Cosmic chronometer data and Pantheon sample of SNeIa data with Markov Chain Monte Carlo (MCMC) techniques. The classical stability of the model is assessed. The model’s parameters are constrained to the best-fit values. The behavior of the deceleration parameter, equation of state, energy density, and pressure is analyzed. Various cosmological diagnostic tools, including the Om diagnostic and energy-condition analysis, are employed to examine the properties of the dark energy component and the dynamical evolution of the Universe. The varying gravitational constant is found to have very small values at the present cosmic time.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 7","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614791","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

Prospects and challenges in developing the next generation astronomical sub-millimetre and terahertz heterodyne receivers 下一代天文亚毫米和太赫兹外差接收机的发展前景和挑战

IF 2.1 4区物理与天体物理

Astrophysics and Space Science Pub Date : 2026-07-29 DOI: 10.1007/s10509-026-04605-0

Boon-Kok Tan

{"title":"Prospects and challenges in developing the next generation astronomical sub-millimetre and terahertz heterodyne receivers","authors":"Boon-Kok Tan","doi":"10.1007/s10509-026-04605-0","DOIUrl":"10.1007/s10509-026-04605-0","url":null,"abstract":"<div><p>The development of next-generation astronomical receivers operating at millimetre (mm), sub-mm, and terahertz frequencies is essential to meet the increasing demand for wide-field, high-spectral-resolution observations. In this work, we examine the prospects and challenges associated with advancing heterodyne receiver technologies, with particular emphasis on superconductor–insulator–superconductor (SIS) mixers. We present a series of technological pathways aimed at enhancing receiver performance, including ultra-broadband RF and IF SIS mixer designs, compact sideband-separating (2SB) architectures enabled by planar superconducting circuit integration, and scalable focal plane array (FPA) concepts capable of supporting hundreds to thousands of pixels. These developments are motivated by the need to significantly improve mapping speed and survey efficiency for future facilities such as ALMA upgrades, AtLAST, LST, and next-generation space missions. Another key contribution of this work is the introduction of simultaneous observing multi-band receivers (SOMBRs), which enable concurrent multi-band 2SB observations through minimal additional hardware by reconfiguring conventional receiver architectures. This approach allows continuous spectral coverage while preserving phase information required for interferometric applications. We discuss the principal challenges in realising these systems, including bandwidth optimisation, impedance matching, local oscillator distribution, and scaling to large-format arrays. Overall, this work outlines a viable pathway towards highly integrated, ultra-broadband, and scalable heterodyne receiver systems, which are expected to play a critical role in enabling the next generation of astronomical discoveries.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 7","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10509-026-04605-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614789","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