The Astrophysical Journal Letters最新文献_第9页

A Core-sensitive Mixed f/g-mode of the Sun Predicted by Wave Topology and Hydrodynamical Simulation 用波拓扑和流体力学模拟预测太阳的核敏感混合f/g模式

The Astrophysical Journal Letters Pub Date : 2025-06-25 DOI: 10.3847/2041-8213/ade396

Arthur Le Saux, Armand Leclerc, Guillaume Laibe, Pierre Delplace and Antoine Venaille

引用次数: 0

An Ejection Event Captured by Very Long Baseline Interferometry during the Outburst of Swift J1727.8–1613 雨燕J1727.8-1613爆发期间的超长基线干涉测量捕获的弹射事件

The Astrophysical Journal Letters Pub Date : 2025-06-25 DOI: 10.3847/2041-8213/ade0ab

Hongmin Cao, Jun Yang, Sándor Frey, Callan M. Wood, James C. A. Miller-Jones, Krisztina É. Gabányi, Giulia Migliori, Marcello Giroletti, Lang Cui, Tao An, Xiaoyu Hong and WeiHua Wang

{"title":"An Ejection Event Captured by Very Long Baseline Interferometry during the Outburst of Swift J1727.8–1613","authors":"Hongmin Cao, Jun Yang, Sándor Frey, Callan M. Wood, James C. A. Miller-Jones, Krisztina É. Gabányi, Giulia Migliori, Marcello Giroletti, Lang Cui, Tao An, Xiaoyu Hong and WeiHua Wang","doi":"10.3847/2041-8213/ade0ab","DOIUrl":"https://doi.org/10.3847/2041-8213/ade0ab","url":null,"abstract":"We observed a newly discovered Galactic black hole X-ray binary Swift J1727.8–1613 with the European VLBI Network (EVN) at 5 GHz. The observation was conducted immediately following a radio quenching event detected by the Karl G. Jansky Very Large Array. The visibility amplitude evolution over time reveals a large-amplitude radio flare and is consistent with an ejection event. The data can be interpreted either as a stationary component (i.e., the radio core) and a moving blob, or as two blobs moving away from the core symmetrically in opposite directions. The initial angular separation speed of the two components was estimated to 30 mas day−1. We respectively fitted a single circular Gaussian model component to each of 14 sliced visibility data sets. For the case of including only European baselines, during the final hour of the EVN observation, the fitted sizes exhibited linear expansion, indicating that the measured sizes were dominated by the angular separation of the two components. The 6 hr EVN observation took place in a rising phase of an even larger 4 day long radio flare, implying that the ejection events were quite frequent and therefore continuous radio monitoring is necessary to correctly estimate the power of the transient jet. Combined with X-ray monitoring data, the radio quenching and subsequent flares/ejections were likely driven by instabilities in the inner hot accretion disk.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144488890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Candidate Spectral Lines at 6 and 15 MeV from GRB 200829A and GRB 160905A GRB 200829A和GRB 160905A 6 MeV和15 MeV的候选谱线

The Astrophysical Journal Letters Pub Date : 2025-06-25 DOI: 10.3847/2041-8213/ade4b8

Tong-Lei Liao, Shuo Xiao, Shao-Lin Xiong, Yan-Qiu Zhang, Wang-Chen Xue, Jiao-Jiao Yang, Zheng-Huo Jiang, Shu-Xu Yi, Zhen Zhang and Shuang-Nan Zhang

{"title":"Candidate Spectral Lines at 6 and 15 MeV from GRB 200829A and GRB 160905A","authors":"Tong-Lei Liao, Shuo Xiao, Shao-Lin Xiong, Yan-Qiu Zhang, Wang-Chen Xue, Jiao-Jiao Yang, Zheng-Huo Jiang, Shu-Xu Yi, Zhen Zhang and Shuang-Nan Zhang","doi":"10.3847/2041-8213/ade4b8","DOIUrl":"https://doi.org/10.3847/2041-8213/ade4b8","url":null,"abstract":"The discoveries of the evolving spectral line in gamma-ray burst (GRB) 221009A provide valuable information for understanding its extreme physical environment and emission mechanisms. In this work, we perform a comprehensive search for 3941 GRBs recorded in the Fermi/Gamma-ray Burst Monitor (GBM) from 2008 July to 2025 February; although no confirmed spectral lines are found, two spectral line candidates at ∼15 and ∼6 MeV in GRB 160905A and GRB 200829A are identified, respectively. Interestingly, the latter’s rest-frame line energy ∼13 MeV at redshift z = 1.25 is similar to that of GRB 221009A at z = 0.151. If this is true, it implies that they may share a common physical origin, possibly linked to blueshifted electron–positron annihilation processes within relativistic jets. Finally, this comprehensive search reveals no >5σ significant line features across the GBM GRB sample, with only two candidates at ∼3σ level. These results place meaningful constraints on the peculiarity and possible origin of the spectral line observed in GRB 221009A.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144488894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Correlations between Event Rates of Short Gamma-Ray Bursts and Star Formation Rates with/without Time Delay 有/无时间延迟时短伽马射线暴事件率与恒星形成率的相关性

The Astrophysical Journal Letters Pub Date : 2025-06-25 DOI: 10.3847/2041-8213/ade1d0

X. Y. Du, Z. B. Zhang, W. C. Du, G. A. Li, Y. Liu and H. C. Liu

{"title":"Correlations between Event Rates of Short Gamma-Ray Bursts and Star Formation Rates with/without Time Delay","authors":"X. Y. Du, Z. B. Zhang, W. C. Du, G. A. Li, Y. Liu and H. C. Liu","doi":"10.3847/2041-8213/ade1d0","DOIUrl":"https://doi.org/10.3847/2041-8213/ade1d0","url":null,"abstract":"In this Letter, we systematically investigate the redshift and luminosity distributions as well as the event rates of short gamma-ray bursts (SGRBs) detected by Swift, Fermi, and Konus–Wind satellites. It is found that the distributions of redshift and luminosity of Fermi and Konus–Wind SGRBs are identical, and they obviously differ from those of Swift/Burst Alert Telescope (BAT) SGRBs. The luminosity distributions of SGRBs detected by diverse detectors can be uniformly fitted by a smoothly broken power-law function. The median luminosity of Swift SGRBs is about 1 order of magnitude smaller than that of Fermi/Gamma-ray Burst Monitor (GBM) or Konus–Wind SGRBs. We also compare the local event rates of Swift/BAT, Fermi/GBM, and Konus–Wind SGRBs and find that the local rate of Swift SGRBs is around 2 orders of magnitude larger than that of either Fermi or Konus–Wind SGRBs, while the latter two rates are comparable. The observed SGRB rates can be successfully fitted by a power law plus Gauss function. The SGRB rates of three kinds of detectors match the delayed/undelayed star formation rates (SFRs) well, except the delayed lognormal and/or Gaussian SFRs at higher redshift, and exceed all types of SFRs at lower redshifts of z < 1. After deducting the diverse SFR components from the SGRB rates, to our surprise, we notice that the remaining SGRB rates steeply decline with redshift in a power-law-like form, indicating that these SGRBs could emerge from the old star populations or compact binary star mergers.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"152 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144516011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Supermassive Black Holes Stripping a Subgiant Star Down to Its Helium Core: A New Type of Multimessenger Source for LISA 超大质量黑洞将一颗次巨星剥离至其氦核：LISA的一种新型多信使源

The Astrophysical Journal Letters Pub Date : 2025-06-25 DOI: 10.3847/2041-8213/ade432

Aleksandra Olejak, Jakob Stegmann, Selma E. de Mink, Ruggero Valli, Re’em Sari, Stephen Justham and Taeho Ryu

{"title":"Supermassive Black Holes Stripping a Subgiant Star Down to Its Helium Core: A New Type of Multimessenger Source for LISA","authors":"Aleksandra Olejak, Jakob Stegmann, Selma E. de Mink, Ruggero Valli, Re’em Sari, Stephen Justham and Taeho Ryu","doi":"10.3847/2041-8213/ade432","DOIUrl":"https://doi.org/10.3847/2041-8213/ade432","url":null,"abstract":"Some stars orbiting supermassive black holes (SMBHs) are expected to undergo a gravitational wave (GW)–driven inspiral and initiate mass transfer on nearly circular orbits. However, the stability and duration of such phases remain unexplored. In this work, we focus on the evolution of a low-mass, radiative-envelope subgiant star being stripped by an SMBH. We find that such systems can undergo a long-lasting, stable mass transfer phase, even if none of the angular momentum of the transferred material returns to the orbit to counterbalance the GW-driven decay. We show an example where a 2 M⊙ subgiant is stripped before entering the Laser Interferometer Space Antenna (LISA) band and loses almost its entire hydrogen envelope. The remaining helium core undergoes a prolonged GW-driven inspiral, becoming a loud LISA source. If formed in our Galaxy, the system would be detectable for several hundred thousand years, ultimately reaching extreme signal-to-noise ratios of a million. Hydrogen shell flashes in the residual envelope cause temporary radial expansions of the stripped star. As a result, a few additional phases of rapid mass transfer occur at orbital periods of 20–30 hr. Eventually, the core possibly undergoes circular partial tidal disruption at an orbital period of ∼10 minutes, corresponding to a GW emission frequency of a few mHz. We estimate a chance of about 1% that such a detectable LISA source exists in our own Galactic center. The loud final GW transient may lead to a few detections reaching as far as ∼1 Gpc, including, e.g., the Abell clusters.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144516149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tides Tighten the Hycean Habitable Zone 潮汐收紧海洋宜居带

The Astrophysical Journal Letters Pub Date : 2025-06-25 DOI: 10.3847/2041-8213/ade434

Joseph R. Livesey, Juliette Becker and Susanna L. Widicus Weaver

引用次数: 0

Thermodynamic Evolution of Flaring Loops with Nonlocal Thermal Transport 具有非局部热输运的燃烧环的热力学演化

The Astrophysical Journal Letters Pub Date : 2025-06-25 DOI: 10.3847/2041-8213/ade542

S. Belov, T. Parmenter, T. Arber, D. Kolotkov, F. Reale and T. Goffrey

{"title":"Thermodynamic Evolution of Flaring Loops with Nonlocal Thermal Transport","authors":"S. Belov, T. Parmenter, T. Arber, D. Kolotkov, F. Reale and T. Goffrey","doi":"10.3847/2041-8213/ade542","DOIUrl":"https://doi.org/10.3847/2041-8213/ade542","url":null,"abstract":"Hot solar coronal loops, such as flaring loops, reach temperatures where the thermal transport becomes nonlocal. This occurs when the mean-free-path of electrons can no longer be assumed to be small. Using a modified version of the Lare2d code, we study the evolution of flare-heated coronal loops under three thermal transport models: classical Spitzer–Härm (SH), a flux-limited (FL) local model, and the nonlocal Schurtz–Nicolaï–Busquet (SNB) model. The SNB model is used extensively in laser-plasma studies. It has been benchmarked against accurate nonlocal Vlasov–Fokker–Planck models and proven to be the most accurate nonlocal model that can be applied on fluid timescales. Analysis of the density–temperature evolution cycles near the loop apex reveals a distinct evolutionary path for the SNB model, with higher temperatures and lower densities than local models. During energy deposition, the SNB model produces a more localized and intense temperature peak at the apex due to heat flux suppression, which also reduces chromospheric evaporation and results in lower postflare densities. Extreme-ultraviolet emission synthesis shows that the SNB model yields flare light curves with lower peak amplitudes and smoother decay phases. We also find that nonlocal transport affects equilibrium loop conditions, producing hotter and more rarefied apexes. These findings emphasize the need to account for nonlocal conduction in dynamic solar phenomena and highlight the potential of the SNB model for improving the realism of flare simulations. FL conduction models cannot reproduce the results of nonlocal transport covered by the SNB model.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144488895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Disintegrating Rocky World Shrouded in Dust and Gas: Mid-infrared Observations of K2-22 b Using JWST 一个被尘埃和气体笼罩的破碎的岩石世界：利用JWST对K2-22 b的中红外观测

The Astrophysical Journal Letters Pub Date : 2025-06-24 DOI: 10.3847/2041-8213/addfd0

Nick Tusay, Jason T. Wright, Thomas G. Beatty, Steve Desch, Knicole Colón, Tushar Mittal, Hugh P. Osborn, Beatriz Campos Estrada, James E. Owen, Jessica Libby-Roberts, Arvind F. Gupta, Brad Foley, Erik Meier Valdés, Daniel J. Stevens and Ashley Herbst

{"title":"A Disintegrating Rocky World Shrouded in Dust and Gas: Mid-infrared Observations of K2-22 b Using JWST","authors":"Nick Tusay, Jason T. Wright, Thomas G. Beatty, Steve Desch, Knicole Colón, Tushar Mittal, Hugh P. Osborn, Beatriz Campos Estrada, James E. Owen, Jessica Libby-Roberts, Arvind F. Gupta, Brad Foley, Erik Meier Valdés, Daniel J. Stevens and Ashley Herbst","doi":"10.3847/2041-8213/addfd0","DOIUrl":"https://doi.org/10.3847/2041-8213/addfd0","url":null,"abstract":"The disintegrating ultrashort period rocky exoplanet K2-22 b periodically emits dusty clouds in a dynamically chaotic process resulting in a variable transit depth from 0% to 1.3%. The effluents that sublimate off the surface and condense out in space are probably representative of the formerly interior layers convectively transported to the molten surface. Transmission spectroscopy of these transiting clouds reveals spectral fingerprints of the interior composition of this rocky world. We used JWST’s Mid-Infrared Instrument as a low-resolution slitless spectrograph to observe four predicted transit windows for K2-22 b. For each observation, we extracted a transmission spectrum over the spectral range of 4.4–11.8 μm. Over the spectral range of 4.4–8 μm, where the spectral precision is highest, we detect one transit at high significance and two at low significance. While the signal-to-noise ratio of the spectrum limits our ability to draw firm conclusions, we find that the data (1) disfavor featureless, iron-dominated core material, (2) are consistent with some form of magnesium silicate minerals, likely from mantle material, and (3) show a distinct and unexpected feature at ∼5 μm. The unexpected feature, also seen weakly in the low-significance transits, is consistent with an unknown gaseous absorber, possibly NO and/or CO2. These findings warrant further study to improve the constraints on the composition of this disintegrating rocky world.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"246 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144488896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deciphering the Formation and Dynamics of Double-decker Filaments through Component Magnetic Reconnection 通过分量磁重联解读双层细丝的形成和动力学

The Astrophysical Journal Letters Pub Date : 2025-06-23 DOI: 10.3847/2041-8213/addfca

Dongxu Liu, Yuandeng Shen, Yi Bi, Zehao Tang, Chengrui Zhou and Surui Yao

{"title":"Deciphering the Formation and Dynamics of Double-decker Filaments through Component Magnetic Reconnection","authors":"Dongxu Liu, Yuandeng Shen, Yi Bi, Zehao Tang, Chengrui Zhou and Surui Yao","doi":"10.3847/2041-8213/addfca","DOIUrl":"https://doi.org/10.3847/2041-8213/addfca","url":null,"abstract":"The formation of double-decker filaments has long been an enigma in the field of solar physics. Using stereoscopic observations from the Solar Dynamics Observatory and the Solar Terrestrial Relations Observatory, we show that the double-decker filament formed on 2013 August 30 resulted from the splitting of a braided magnetic flux rope. The splitting was driven by component magnetic reconnection between intertwined field lines, triggered by the rotational motion in a part of one filament footpoint. This mechanism, inferred from observed small jets, brightenings, and bidirectional mass flows, differs from the previous conclusion attributing filament splitting to magnetic reconnection between the legs of confining magnetic field lines within or above the filament. The splitting speed might be modulated by the reconnection speed, as evidenced by the correspondence between the filament’s slow and fast rising phases and the intermittent and violent brightening stages. Following the splitting, the upper branch of the double-decker filament erupted as a coronal mass ejection, giving rise to a GOES soft X-ray M1.2 flare. In conclusion, our observations present a new formation mechanism for double-decker filaments, and the subsequent partial eruption is likely attributable to the torus instability of the background coronal magnetic field. Moreover, the detection of small jets within the filament provides new insights into the role of component magnetic reconnection in localized coronal heating processes.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"248 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144478958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Intense Hard X-Ray Emissions in C-class Flares: A Statistical Study with ASO-S/HXI Data c级耀斑的强硬x射线辐射：基于ASO-S/HXI数据的统计研究

The Astrophysical Journal Letters Pub Date : 2025-06-23 DOI: 10.3847/2041-8213/addf2f

Changxue Chen, Yang Su, Wei Chen, Jingwei Li, Fu Yu and Weiqun Gan

{"title":"Intense Hard X-Ray Emissions in C-class Flares: A Statistical Study with ASO-S/HXI Data","authors":"Changxue Chen, Yang Su, Wei Chen, Jingwei Li, Fu Yu and Weiqun Gan","doi":"10.3847/2041-8213/addf2f","DOIUrl":"https://doi.org/10.3847/2041-8213/addf2f","url":null,"abstract":"In the standard model of solar eruptive events, coronal mass ejections (CMEs) and flares are associated with each other through magnetic reconnection initiated by erupting flux ropes. Observations also reveal an increasing association ratio between flares and CMEs with flare intensity. However, the fundamental relationship between flares and CMEs, and that between thermal and nonthermal processes, remains unknown. Here we investigate energetic C-class flares (ECFs)—Geostationary Operational Environmental Satellite (GOES) C-class flares with hard X-ray (HXR) emissions above 30 keV—using observations from Advanced Space-based Solar Observatory/Hard X-ray Imager (HXI), Solar Dynamic Observatory, and GOES. Among 1331 C-class flares detected by HXI, 127 ECFs (9.5%) were identified for statistical analysis of their properties and associations with CMEs and other flare-related features. Our statistical results reveal that ECFs have relatively shorter durations and harder spectra (the mean electron power-law index is 4.65), with no significant correlation between soft X-ray flux and nonthermal parameters (e.g., HXR peak flux). Among the 127 events, 53 (42%) were associated with type III bursts, 38 (30%) with jets, at least 13 (∼11%) with 360 nm brightenings, and only 5 (∼4%) with CMEs. Crucially, all five CME events were narrow CMEs associated with jets. The surprising weak correlation between these ECFs and CMEs suggests that noneruptive or confined magnetic field configurations in these flares may favor electron acceleration, resulting in harder X-ray spectra. We discuss the potential formation mechanisms and efficient electron acceleration processes in these atypical flares, providing valuable insights into nonstandard flare behavior.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144370959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0