Journal of High Energy Astrophysics最新文献_第10页

High mass pulsars as hybrid stars: Phase transitions and oscillation modes 作为混合星的高质量脉冲星：相变和振荡模式

IF 10.5 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-09-09 DOI: 10.1016/j.jheap.2025.100457

Soumen Podder , Sujan Kumar Roy , Suman Pal , Gargi Chaudhuri

Recent observations of high-mass pulsars justify the investigation of the internal composition of neutron stars. At the extreme densities relevant to such objects, quantum chromodynamics predicts a phase transition in neutron star matter to deconfined quark matter. However, the nature of this phase transition remains uncertain due to the absence of direct observational evidence. In this work, we investigate the possibility of such a transition inside neutron stars, focusing on the scenario of a first-order phase transition. In particular, we consider the slow conversion of the hadronic phase into the deconfined quark phase. For comparison, we also construct hybrid stars using a continuous Gibbs phase transition description. Our findings indicate that the neutron star structure is significantly influenced by the adopted phase transition model. In the context of gravitational wave observations, we analyze the non-radial f-mode oscillations in high-mass pulsars. We find that these oscillations are sensitive to both the nature of the phase transition and the underlying neutron star structure. Consequently, we explore neutron star oscillations as a potential probe of the internal composition of high-mass pulsars, as these oscillation modes can provide signatures of phase transitions.

最近对高质量脉冲星的观测证明了中子星内部组成的研究是正确的。在与这些物体相关的极端密度下，量子色动力学预测了中子星物质向限定夸克物质的相变。然而，由于缺乏直接观测证据，这种相变的性质仍然不确定。在这项工作中，我们研究了中子星内部这种转变的可能性，重点是一阶相变的情况。特别地，我们考虑了强子相向限定夸克相的缓慢转换。为了比较，我们还使用连续吉布斯相变描述构造了混合恒星。我们的研究结果表明，采用的相变模型对中子星结构有显著影响。在引力波观测的背景下，我们分析了大质量脉冲星的非径向f模振荡。我们发现这些振荡对相变的性质和潜在的中子星结构都很敏感。因此，我们探索中子星振荡作为高质量脉冲星内部组成的潜在探针，因为这些振荡模式可以提供相变的特征。

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引用次数: 0

Does DESI 2024 confirm ΛCDM? 清洁发展机制2024 doc DESI confirmΛ?

IF 10.2 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-07-23 DOI: 10.1016/j.jheap.2025.100428

E. Ó Colgáin , M.G. Dainotti , S. Capozziello , S. Pourojaghi , M.M. Sheikh-Jabbari , D. Stojkovic

We demonstrate that a

\sim 2 σ

discrepancy with the Planck-ΛCDM cosmology in DESI Luminous Red Galaxy (LRG) data in the redshift range

0.4 < z < 0.6

with effective redshift

z_{eff} = 0.51

translates into an unexpectedly large

Ω_{m}

value,

Ω_{m} = {0.67}_{- 0.17}^{+ 0.18}

. We independently confirm that this anomaly drives the preference for

w_{0} > - 1

in DESI data alone confronted to the

w_{0} w_{a}

CDM model. Given that LRG data at

z_{eff} = 0.51

is at odds with Type Ia supernovae in overlapping redshifts, we expect that this anomaly will decrease in statistical significance with future DESI data releases leaving an increasing

Ω_{m}

trend with effective redshift at higher redshifts. We estimate the current significance of the latter in DESI data at

\sim 1.8 σ

and comment on how it dovetails with independent observations. It is imperative to understand what makes DESI LRG data at

z_{eff} = 0.51

an outlier when it comes to

Ω_{m}

determinations.

我们证明，在有效红移zeff=0.51的红移范围0.4<z<；0.6的DESI发光红星系（LRG）数据中，与普朗克-ΛCDM宇宙学的~ 2σ差异转化为意想不到的大Ωm值，Ωm=0.67−0.17+0.18。我们独立地证实，在面对w0waCDM模型的DESI数据中，这种异常驱动了对w0>；−1的偏好。考虑到zeff=0.51处的LRG数据与Ia型超新星在重叠红移上不一致，我们预计随着未来DESI数据的发布，这种异常的统计显著性将降低，在更高的红移处留下一个增加Ωm的趋势，有效的红移。我们估计后者在DESI数据中的当前意义为~ 1.8σ，并评论了它如何与独立观测相吻合。当涉及Ωm确定时，必须理解是什么使zeff=0.51的DESI LRG数据成为异常值。

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引用次数: 0

Quasi-Periodic Oscillations due to radiative feedback mechanism between the disc and corona 星盘和日冕之间的辐射反馈机制引起的准周期振荡

IF 10.2 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-07-21 DOI: 10.1016/j.jheap.2025.100426

Akash Garg , Ranjeev Misra , Somasri Sen

Compact object systems exhibit Quasi-Periodic Oscillations (QPOs) as revealed by peaked features in their power density spectra. It has been known that stochastic variations in the accretion disc will propagate to the corona after a time delay and that the hard X-rays from the corona impinge back on the disc, giving reflection spectral features. Here, we show that the combination of these two effects makes a simple radiative feedback system between the corona and the disc, which naturally produces the observed QPOs whose primary frequency corresponds to the inverse of the time delay. The analytical form of the expected power spectra can be statistically compared with the observed ones. Hence for the first time, a physical model is used to describe and fit the AstroSat observed power spectra of the black hole systems MAXI J1535-571 and GRS 1915+105, including the QPO, its harmonics as well as the broadband components.

紧凑物体系统具有准周期振荡（QPOs），其功率密度谱的峰值特征揭示了这一点。我们已经知道，吸积盘的随机变化会在一段时间延迟后传播到日冕，而来自日冕的硬x射线会反射回吸积盘，从而给出反射光谱特征。在这里，我们证明了这两种效应的结合在日冕和星盘之间形成了一个简单的辐射反馈系统，它自然地产生了观测到的qpo，其主要频率对应于时间延迟的倒数。期望功率谱的解析形式可以与观测值进行统计比较。因此，首次使用物理模型来描述和拟合AstroSat观测到的MAXI J1535-571和GRS 1915+105黑洞系统的功率谱，包括QPO、谐波和宽带分量。

引用次数: 0

NuSTAR discovers a long type-I X-ray burst from the clocked burster GS 1826-24 核星发现了一个长i型x射线爆发从时钟爆发GS 1826-24

IF 10.5 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-08-18 DOI: 10.1016/j.jheap.2025.100450

Aditya S. Mondal , Mayukh Pahari , Gulab C. Dewangan

The source GS 1826-24 is a neutron star low mass X-ray binary known as the “clocked burster” because of its extremely regular bursting behavior. We report on the detection of a long type-I X-ray burst from this source. We perform a detailed spectroscopic analysis of the long X-ray burst, lasting for ∼600 s, seen in the NuSTAR observation carried out on 2022 September. The persistent emission is well described by an absorbed thermal Comptonization model nthcomp, and the source exhibits a soft spectral state during this observation. The observed burst exhibits a rise time of ∼25 s and a decay time of ∼282 s. The time-resolved spectroscopy of the burst shows a significant departure from a pure thermal spectrum and is described with a model consisting of a varying-temperature blackbody plus an evolving persistent emission component. We observe a significant enhancement in the persistent emission during the burst. The enhancement of the pre-burst persistent flux is possibly due to Poynting-Robertson drag or coronal reprocessing. At the peak of the burst, the blackbody temperature and the blackbody emitting radius reached a maximum of

2.10 \pm 0.07

keV and

5.5 \pm 2.1

km, respectively. The peak flux (

F_{p e a k}

) during the burst is

\approx 2.4 \times 10^{- 8}

ergs cm⁻² s⁻¹, which corresponds to a luminosity of

\approx 9.7 \times 10^{37}

ergs s⁻¹.

源GS 1826-24是一颗中子星低质量x射线双星，因其极其规律的爆炸行为而被称为“定时爆炸”。我们报告了从这个源探测到的长i型x射线爆发。我们对2022年9月进行的核星观测中持续约600秒的长x射线爆发进行了详细的光谱分析。持续的发射可以用吸收热复合模型很好地描述，并且在此观测期间源表现出软光谱状态。观测到的爆发显示出上升时间为~ 25秒，衰减时间为~ 282秒。爆发的时间分辨光谱显示出与纯热光谱的显著差异，并用一个由变温黑体加上不断演变的持续发射成分组成的模型来描述。我们观察到在爆发期间持续发射的显著增强。爆发前持续通量的增强可能是由于波印廷-罗伯逊阻力或日冕再处理所致。在爆发高峰期，黑体温度和黑体发射半径分别达到2.10±0.07 keV和5.5±2.1 km的最大值。爆发期间的峰值通量（Fpeak）为≈2.4×10−8 ergs cm−2 s−1，对应的光度为≈9.7×1037 ergs−1。

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引用次数: 0

Balancing accessibility and quality: How high energy astrophysics supports a diverse scientific community 平衡可及性和质量：高能天体物理学如何支持多样化的科学界

IF 10.5 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-07-08 DOI: 10.1016/j.jheap.2025.100423

引用次数: 0

Maximum mass of singularity-free anisotropic compact stars in Rastall theory of gravity 拉斯托引力理论中无奇点各向异性致密星的最大质量

IF 10.5 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-08-07 DOI: 10.1016/j.jheap.2025.100445

Sourav Biswas, Debadri Bhattacharjee, Pradip Kumar Chattopadhyay

The current model explores spherically symmetric anisotropic compact stars within the Rastall theory of gravity. By employing the Krori and Barua metric ansatz Krori and Barua (1975), we derive a set of tractable, singularity-free relativistic solutions to the Einstein field equations. Using a best-fit equation for the numerical solution of the TOV equation, we determine the maximum mass and corresponding radius in this model. Our findings reveal that an increase in the Rastall parameter (ξ) leads to a higher maximum mass, indicating a stiffer nature of the equation of state. For ξ values ranging from 0.01 to 0.09, we calculate the maximum mass to be between

2.24 M_{⊙}

and

2.36 M_{⊙}

, with corresponding radii from 9.48 to 10.15 km. Furthermore, our model's predictions for the radii of recently observed pulsars are consistent with observational data. The model satisfies essential criteria for causality, energy conditions, and stability, confirming its viability and physical acceptability as a stellar structure.

目前的模型在拉斯托引力理论中探索球对称各向异性致密恒星。通过使用Krori和Barua度量分析（1975），我们导出了一组易于处理的、无奇点的爱因斯坦场方程的相对论解。利用TOV方程数值解的最佳拟合方程，确定了该模型的最大质量和相应的半径。我们的研究结果表明，拉斯托参数（ξ）的增加会导致最大质量的增加，这表明状态方程的性质更硬。对于ξ值从0.01到0.09，我们计算出最大质量在2.24M⊙到2.36M⊙之间，相应的半径从9.48到10.15 km。此外，我们的模型对最近观测到的脉冲星半径的预测与观测数据是一致的。该模型满足因果关系、能量条件和稳定性的基本标准，确认了其作为恒星结构的可行性和物理可接受性。

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引用次数: 0

A set of distinctive properties ruling the prompt emission of GRB 230307A and other long γ-ray bursts from compact object mergers GRB 230307A和其他紧凑天体合并产生的长γ射线爆发的一系列独特特性

IF 10.5 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-09-03 DOI: 10.1016/j.jheap.2025.100456

R. Maccary , C. Guidorzi , M. Maistrello , S. Kobayashi , M. Bulla , R. Moradi , S.-X. Yi , C.W. Wang , W.L. Zhang , W.-J. Tan , S.-L. Xiong , S.-N. Zhang

Short gamma-ray bursts (SGRBs), occasionally followed by a long and spectrally soft extended emission, are associated with compact object mergers (COMs). Yet, a few recent long GRBs (LGRBs) show compelling evidence for a COM origin, in contrast with the massive-star core-collapse origin of most LGRBs. While possible COM indicators were found, such as the minimum variability timescale (MVT), a detailed and unique characterisation of their γ-ray prompt emission that may help identify and explain their deceptively long profile is yet to be found. Here we report the discovery of a set of distinctive properties that rule the temporal and spectral evolution of GRB 230307A, a LGRB with evidence for a COM origin. Specifically, the sequence of pulses that make up its profile is characterised by an exponential evolution of (i) flux intensities, (ii) waiting times between adjacent pulses, (iii) pulse durations, and (iv) spectral peak energy. Analogous patterns are observed in the prompt emission of other long COM candidates. The observed evolution of gamma-ray pulses would imply that a relativistic jet is colliding with more slowly expanding material. This contrasts with the standard internal shock model for typical LGRBs, in which dissipation occurs at random locations within the jet itself. We tentatively propose a few simple toy models that may explain these properties and are able to reproduce the overall time profile.

短伽马射线暴（sgrb），偶尔伴随着长而光谱柔和的扩展发射，与紧凑物体合并（COMs）有关。然而，最近的一些长伽马射线暴（lgrb）显示了令人信服的证据，证明其起源是COM，而不是大多数lgrb的大质量恒星核心坍缩起源。虽然发现了可能的COM指标，例如最小变率时间尺度（MVT），但尚未发现其γ射线提示发射的详细和独特特征，这可能有助于识别和解释其看似长的剖面。在这里，我们报告了GRB 230307A的一组独特特性的发现，这些特性支配着GRB 230307A的时间和光谱演化，这是一个有证据表明起源于COM的LGRB。具体而言，构成其剖面的脉冲序列的特征是(i)通量强度，（ii）相邻脉冲之间的等待时间，（iii）脉冲持续时间和（iv）光谱峰值能量的指数演变。在其他长COM候选者的提示发射中也观察到类似的模式。观测到的伽玛射线脉冲的演化意味着相对论性喷流正在与更缓慢膨胀的物质碰撞。这与典型lgrb的标准内部激波模型形成了对比，在这种模型中，耗散发生在射流本身的随机位置。我们暂时提出了几个简单的玩具模型，可以解释这些属性，并能够重现整体的时间概况。

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引用次数: 0

Fermi-large area telescope detection of very high energy (>100 GeV) emission from misaligned jetted active galactic nuclei 费米-大面积望远镜探测到来自错位喷射的活动星系核的高能（bbb100 GeV）发射

IF 10.5 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-09-01 DOI: 10.1016/j.jheap.2025.100454

Gunjan Tomar , Vaidehi S. Paliya , D.J. Saikia , C.S. Stalin

The detection of very-high-energy (VHE; >100 GeV) γ-ray radiation from misaligned jetted Active Galactic Nuclei (AGN) challenges the emission models that primarily explain VHE emissions from beamed AGN, i.e., blazars. Using over 16 years of Fermi-Large Area Telescope (Fermi-LAT) Pass 8 data in the energy range 0.1−2 TeV, we systematically explore the VHE emission from a recently published sample of 160 radio galaxies. We identify 12 sources detected at

> 4 σ

confidence level (test statistic or TS>16), including nine with TS>25 and two Fanaroff-Riley type II objects. This detected sample includes seven out of eight previously known VHE objects. Two radio galaxies are detected in the VHE band for the first time, and we identify three promising candidates with 16<TS<25. Additionally, 13 objects are identified as candidate VHE emitters with at least one VHE photon detected with the Fermi-LAT. These findings expand the sample of known VHE-emitting radio galaxies, whose multiwavelength follow-up observations can help provide insights into the emission mechanisms, jet physics, and the contribution of misaligned AGN to the extragalactic γ-ray background.

探测到来自失调喷射的活动星系核（AGN）的高能(VHE; >100 GeV) γ射线辐射，挑战了主要解释来自束状活动星系核（即耀变体）的VHE辐射的发射模型。利用Fermi-Large Area Telescope (Fermi-LAT) Pass 8在0.1 - 2 TeV能量范围内超过16年的数据，我们系统地探索了最近发表的160个射电星系样本的VHE发射。我们确定了12个在>；4σ置信水平（检验统计量或TS>；16）检测到的源，包括9个TS>；25和2个Fanaroff-Riley II型对象。这个探测到的样本包括了之前已知的8个VHE天体中的7个。在VHE波段首次探测到两个射电星系，我们用16<；TS<；25确定了三个有希望的候选星系。此外，13个物体被确定为候选的VHE发射体，至少有一个VHE光子被费米- lat探测到。这些发现扩大了已知的vhe发射射电星系的样本，其多波长后续观测有助于深入了解发射机制，射流物理以及失调AGN对河外γ射线背景的贡献。

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引用次数: 0

Empirical validation: Investigating the ΛsCDM model with new DESI BAO observations 实证验证：用新的DESI BAO观测资料研究ΛsCDM模型

IF 10.5 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-08-28 DOI: 10.1016/j.jheap.2025.100453

Manish Yadav , Archana Dixit , Anirudh Pradhan , M.S. Barak

The ΛCDM model has long served as the cornerstone of modern cosmology, offering an elegant and successful framework for interpreting a wide range of cosmological observations. However, the rise of high-precision datasets has revealed statistically significant tensions, most notably the Hubble tension and the

S_{8}

discrepancy, which challenge the completeness of this standard model. In this context, we explore the

Λ_{s}

CDM model—an extension of ΛCDM featuring a single additional parameter,

z_{†}

, corresponding to a sign-switching cosmological constant. This minimal modification aims to alleviate key observational tensions without compromising the model's overall coherence. Recent findings present in the literature indicate that the

Λ_{s}

CDM model not only provides a better fit to Lyman-α forest data for

z_{†} < 2.3

, but also accommodates both the SH0ES measurement of

H_{0}

and the angular diameter distance to the last scattering surface when 2D BAO data are included. We present a comprehensive analysis combining the full Planck 2018 CMB data, the Pantheon Type Ia Supernovae sample, and the recently released Baryon Acoustic Oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI). Our finding reveal that the Preliminary DESI results, a possible 3.9σ deviation from ΛCDM expectations, reinforce the importance of exploring such dynamic dark energy frameworks. In sum, our study underscores the potential of

Λ_{s}

CDM to reconcile multiple cosmological tensions and sheds light on the role of upcoming high-precision observations in reshaping our understanding of the universe's expansion history and the nature of dark energy.

ΛCDM模型长期以来一直是现代宇宙学的基石，为解释广泛的宇宙学观测提供了一个优雅而成功的框架。然而，高精度数据集的兴起揭示了统计上显著的张力，最显著的是哈勃张力和S8差异，它们挑战了这个标准模型的完整性。在这种情况下，我们探索ΛsCDM模型- ΛCDM的扩展，具有单个附加参数z†，对应于符号切换的宇宙学常数。这种最小的修改旨在减轻关键观测的紧张，而不损害模型的整体一致性。最近的研究结果表明，ΛsCDM模型不仅能较好地拟合z†<；2.3的Lyman-α森林数据，而且在包含二维BAO数据时，也能适应H0的SH0ES测量值和到最后散射面的角直径距离。我们结合普朗克2018年的完整CMB数据，万神殿Ia型超新星样本以及最近发布的暗能量光谱仪器（DESI）的重子声学振荡（BAO）测量结果进行了综合分析。我们的发现表明，DESI的初步结果（可能与ΛCDM预期偏差3.9σ）强化了探索这种动态暗能量框架的重要性。总之，我们的研究强调了ΛsCDM调和多重宇宙学张力的潜力，并阐明了即将到来的高精度观测在重塑我们对宇宙膨胀历史和暗能量本质的理解方面的作用。

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引用次数: 0

Lorentz violation with gravitational waves: Constraints from NANOGrav and IPTA data 引力波的洛伦兹违背：来自nanogravity和IPTA数据的约束

IF 10.5 4区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Journal of High Energy Astrophysics

Pub Date : 2026-01-01 Epub Date: 2025-08-14 DOI: 10.1016/j.jheap.2025.100448

Alireza Allahyari , Mohammadreza Davari , David F. Mota

We explore a theoretical framework in which Lorentz symmetry is explicitly broken by incorporating derivative terms of the extrinsic curvature into the gravitational action. These modifications introduce a scale-dependent damping effect in the propagation of gravitational waves (GWs), governed by a characteristic energy scale denoted as

M_{LV}

. Tightest constraints on

M_{LV}

are achieved when we assume GWs have a primordial origin. In this scenario, we derive the modified spectral energy density of GWs and confront it with recent observational data from the NANOGrav 15-year dataset and the second data release of the International Pulsar Timing Array (IPTA). Our analysis yields a lower bound on the Lorentz-violating energy scale, finding

M_{LV} > 10^{- 19}

GeV at 68% confidence level. This result significantly improves upon previous constraints derived from LIGO/VIRGO binary merger observations. Our findings demonstrate the potential of pulsar timing arrays to probe fundamental symmetries of spacetime and offer new insights into possible extensions of general relativity.

我们探索了一个理论框架，在这个框架中，洛伦兹对称通过将外在曲率的导数项纳入引力作用而被明确地打破。这些修正在引力波（GWs）的传播中引入了尺度相关的阻尼效应，由表征为MLV的特征能量尺度控制。当我们假设GWs具有原始起源时，可以实现对MLV的最严格约束。在这种情况下，我们得到了修正的GWs光谱能量密度，并与NANOGrav 15年数据集和国际脉冲星定时阵列（IPTA）第二次发布的数据进行了对比。我们的分析得出了违反洛伦兹能量标度的下界，在68%的置信水平上发现MLV>；10−19 GeV。这一结果显著改善了先前LIGO/VIRGO双子星合并观测的约束条件。我们的发现证明了脉冲星定时阵列探测时空基本对称性的潜力，并为广义相对论的可能扩展提供了新的见解。

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引用次数: 0