The Astrophysical Journal Letters最新文献

{"title":"Time–Frequency Correlation of Repeating Fast Radio Bursts: Correlated Aftershocks Tend to Exhibit Downward Frequency Drifts","authors":"Shotaro Yamasaki and Tomonori Totani","doi":"10.3847/2041-8213/adc10b","DOIUrl":"https://doi.org/10.3847/2041-8213/adc10b","url":null,"abstract":"The production mechanism of fast radio bursts (FRBs)—mysterious, bright, millisecond-duration radio flashes from cosmological distances—remains unknown. Understanding potential correlations between burst occurrence times and various burst properties may offer important clues about their origins. Among these properties, the spectral peak frequency of an individual burst (the frequency at which its emission is strongest) is particularly important because it may encode direct information about the physical conditions and environment at the emission site. Analyzing over 4000 bursts from the three most active sources—FRB 20121102A, FRB 20201124A, and FRB 20220912A—we measure the two-point correlation function ξ(Δt, Δνpeak) in the two-dimensional space of time separation Δt and peak frequency shift Δνpeak between burst pairs. We find a universal trend of asymmetry about Δνpeak at high statistical significance; ξ(Δνpeak) decreases as Δνpeak increases from negative to positive values in the region of short time separation (Δt ≲ 0.3 s), where physically correlated aftershock events produce a strong time correlation signal. This indicates that aftershocks tend to exhibit systematically lower peak frequencies than mainshocks, with this tendency becoming stronger at shorter Δt. We argue that the “sad trombone effect”—the downward frequency drift observed among subpulses within a single event—is not confined within a single event but manifests as a statistical nature that extends continuously to independent yet physically correlated aftershocks with time separations up to Δt ∼ 0.3 s. This discovery provides new insights into underlying physical processes of repeater FRBs.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775675","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}

{"title":"Observational Constraints of Radial Migration in the Galactic Disk Driven by the Slowing Bar","authors":"HanYuan Zhang, Vasily Belokurov, N. Wyn Evans, Jason L. Sanders, Yuxi(Lucy) Lu, Chengye Cao, GyuChul Myeong, Adam M. Dillamore, Sarah G. Kane and Zhao-Yu Li","doi":"10.3847/2041-8213/adc261","DOIUrl":"https://doi.org/10.3847/2041-8213/adc261","url":null,"abstract":"Radial migration is an important dynamical effect that has reshaped the Galactic disk, but its origin has yet to be elucidated. In this work, we present evidence that resonant dragging by the corotation of a decelerating bar could be the main driver of radial migration in the Milky Way disk. Using a test particle simulation, we demonstrate this scenario explains the two distinct age–metallicity sequences observed in the solar vicinity: the plateauing upper sequence is interpreted as stars dragged outward by the expanding corotation of the decelerating bar and the steeper lower sequence as stars formed locally around the solar circle. The upper migrated sequence dominates at guiding radii around the current corotation radius of the bar, R ∼ 7 kpc, but rapidly dies away beyond this where the mechanism cannot operate. This behavior naturally explains the radial dependence of the [α/Fe]-bimodality, in particular the truncation of the high-[α/Fe] disk beyond the solar circle. Under our proposed radial migration scenario, we constrain the Milky Way bar’s pattern speed evolution using the age–metallicity distribution of stars currently trapped at corotation. We find the bar likely formed with an initial pattern speed of 60−100 km s−1 kpc−1 and began decelerating 6−8 Gyr ago at a rate of (where the quoted ranges include systematic uncertainties).","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775677","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}

{"title":"Evidence for Environmental Effects in the z = 4.3 Protocluster Core SPT2349–56","authors":"Chayce Hughes, Ryley Hill, Scott C. Chapman, Manuel Aravena, Melanie Archipley, Veronica J. Dike, Anthony Gonzalez, Thomas R. Greve, Gayathri Gururajan, Chris Hayward, Kedar Phadke, Cassie Reuter, Justin Spilker, Nikolaus Sulzenauer, Joaquin D. Vieira, David Vizgan, George Wang, Axel Weiss and Dazhi Zhou","doi":"10.3847/2041-8213/adc1c9","DOIUrl":"https://doi.org/10.3847/2041-8213/adc1c9","url":null,"abstract":"We present Atacama Large Millimeter/submillimeter Array observations of the [C I] 492 and 806 GHz fine-structure lines in 25 dusty star-forming galaxies (DSFGs) at z = 4.3 in the core of the SPT2349–56 protocluster. The protocluster galaxies exhibit a median ratio of 0.94, with an interquartile range of 0.81–1.24. These ratios are markedly different to those observed in DSFGs in the field (across a comparable redshift and 850 μm flux density range), where the median is 0.55, with an interquartile range of 0.50–0.76, and we show that this difference is driven by an excess of [C i](2–1) in the protocluster galaxies for a given 850 μm flux density. Assuming local thermal equilibrium, we estimate gas excitation temperatures of K for our protocluster sample and K for the field sample. Our main interpretation of this result is that the protocluster galaxies have had their cold gas driven to their cores via close-by interactions within the dense environment, leading to an overall increase in the average gas density and excitation temperature, as well as an elevated [C i](2–1) luminosity-to-far-infrared-luminosity ratio.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143790186","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}

{"title":"X-class Flare on 2023 December 31 Observed by the Solar Ultraviolet Imaging Telescope on Board Aditya-L1","authors":"Soumya Roy, Durgesh Tripathi, Vishal Upendran, Sreejith Padinhatteeri, A. N. Ramaprakash, Nived V. N., K. Sankarasubramanian, Sami K. Solanki, Janmejoy Sarkar, Rahul Gopalakrishnan, Rushikesh Deogaonkar, Dibyendu Nandy and Dipankar Banerjee","doi":"10.3847/2041-8213/adc387","DOIUrl":"https://doi.org/10.3847/2041-8213/adc387","url":null,"abstract":"We present the multiwavelength study of the ejection of a plasma blob from the limb flare SOL2023-12-31T21:36:00 from NOAA 13536 observed by the Solar Ultraviolet Imaging Telescope (SUIT) on board Aditya-L1. We use SUIT observations along with those from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory and Spectrometer/Telescope for Imaging X-rays (STIX) on board Solar Orbiter to infer the kinematics and thermal nature of the ejected blob and its connection to the associated flare. The observations show that the flare was comprised of two eruptions. The blob was ejected during the first eruption and later accelerated to velocities over 1500 km s−1 measured at a maximum projected height of ∼178 Mm from the Sun’s surface. The acceleration of the ejected plasma blob is cotemporal with the bursty appearance of the hard X-ray light curve recorded by STIX. Radio spectrogram observations from STEREO-A/WAVES and RSTN reveal type III bursts at the same time, indicative of magnetic reconnection. DEM analysis using AIA observations suggests the plasma blob is comprised of cooler and denser plasma in comparison to the ambient corona. To the best of our knowledge, this is the first observation of such a plasma blob in the near-ultraviolet providing crucial measurements for eruption thermodynamics.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775680","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}

{"title":"Primordial Origin of Methane on Eris and Makemake Supported by D/H Ratios","authors":"Olivier Mousis, Aaron Werlen, Tom Benest Couzinou and Antoine Schneeberger","doi":"10.3847/2041-8213/adc134","DOIUrl":"https://doi.org/10.3847/2041-8213/adc134","url":null,"abstract":"Deuterium, a heavy isotope of hydrogen, is a key tracer of the formation of the solar system. Recent James Webb Space Telescope observations have expanded the data set of deuterium-to-hydrogen (D/H) ratios in methane on the KBOs Eris and Makemake, providing new insights into their origins. This study examines the elevated D/H ratios in methane on these KBOs in the context of protosolar nebula (PSN) dynamics and chemistry, proposing a primordial origin for the methane, in contrast to previous hypotheses suggesting abiotic production by internal heating. A time-dependent disk model coupled with a deuterium chemistry module was used to simulate the isotopic exchange between methane and hydrogen. Observational constraints, including the D/H ratio measured in methane in comet 67P/Churyumov–Gerasimenko, were used to refine the primordial D/H abundance. The simulations show that the observed D/H ratios in methane on Eris and Makemake are consistent with a primordial origin. The results suggest that the methane on these Kuiper Belt Objects likely originated from the PSN, similar to cometary methane, and was sequestered in solid form—either as pure condensates or clathrates—within its building blocks prior to accretion. These results provide a simple explanation for the high D/H ratios in methane on Eris and Makemake, without the need to invoke internal production mechanisms.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775676","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}

{"title":"Orthogonal Alignment of Galaxy Group Angular Momentum with Cosmic Filament Spines: An Observational Study","authors":"Yu Rong, Peng Wang and Xiao-xiao Tang","doi":"10.3847/2041-8213/adc130","DOIUrl":"https://doi.org/10.3847/2041-8213/adc130","url":null,"abstract":"We investigated the alignment between the angular momenta of galaxy groups and the spines of their associated cosmic filaments. Our results demonstrate a significant tendency for these two orientations to be perpendicular, indicating that the rotation of a galaxy group does not originate from the spin of cosmic filaments. Instead, it is driven by the orbital angular momentum contributed by member galaxies as they accrete along the direction of the filament spines. Moreover, the strength of this perpendicular alignment signal varies with the richness of the galaxy groups, with the most pronounced alignment observed among the wealthiest groups. This pronounced alignment is largely due to the more coherent spatial distribution of member galaxies in richer groups relative to the filament spines. Our study provides valuable insights into the mechanisms of angular momentum acquisition in galaxy groups from an observational standpoint.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766445","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}

{"title":"Exotic Nanophase Iron as a New Agent for Space Weathering on the Moon","authors":"Xiaojia Zeng, Xiaoping Zhang, Yanxue Wu, Wen Yu, Xiongyao Li and Jianzhong Liu","doi":"10.3847/2041-8213/adbf88","DOIUrl":"https://doi.org/10.3847/2041-8213/adbf88","url":null,"abstract":"Nanophase iron (np-Fe) particles in space-weathered lunar regolith are widely concerning as they can change the spectral, chemical, and physical properties of lunar soils. These np-Fe particles were previously believed to be produced from lunar surface materials by space weathering processes, while the source of np-Fe particles from exotic micrometeorite (flux = ∼5 × 108 t/Ma) has been overlooked. In this study, we report the discovery of np-Fe particles in the micrometeorite impactor residue on a plagioclase crystal from Chang’e-5 lunar soil. Our results show that the source of these np-Fe particles does not originate from lunar materials, but rather are sourced from micrometeorites (i.e., exotic origin). This work provides mineralogical evidence that exotic np-Fe particles can be delivered and preserved by micrometeorite impact melting and reduction on the Moon. The estimated production rate of exotic np-Fe particles is as high as ∼5 × 106 t/Ma on the Moon. We therefore suggest that these exotic np-Fe particles have a nonnegligible influence on the interpretation of the space weathering process in special environments (e.g., permanently shadowed regions) of the Moon and other airless planetary bodies in the solar system.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"183 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775682","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}

{"title":"Improving Photometric Redshifts of Epoch of Reionization Galaxies: A New Empirical Transmission Curve with Neutral Hydrogen Damping Wing Lyα Absorption","authors":"Yoshihisa Asada, Guillaume Desprez, Chris J. Willott, Marcin Sawicki, Maruša Bradač, Gabriel Brammer, Florian Dubath, Kartheik G. Iyer, Nicholas S. Martis, Adam Muzzin, Gaël Noirot, Stéphane Paltani, Ghassan T. E. Sarrouh, Anishya Harshan and Vladan Markov","doi":"10.3847/2041-8213/adc388","DOIUrl":"https://doi.org/10.3847/2041-8213/adc388","url":null,"abstract":"We present a new analytical model for the attenuation to Epoch of Reionization (EoR) galaxies by proximate neutral hydrogen gas. Many galaxy spectra in the EoR taken by JWST have shown a flux deficit at wavelengths just redward of the Lyman break, and this has been regarded as resulting from Lyα damping wing absorption by the increasing amount of neutral hydrogen in the line of sight. However, previous attenuation models for the intergalactic medium (IGM) commonly used in photometric redshift template-fitting codes assume that the Lyman break is rather sharp, which leads to systematic overestimation of photometric redshifts at z > 7. In this Letter, we build and empirically calibrate a new attenuation model that takes the increased Lyα damping wing absorption into account. Our model consists of the canonical IGM absorption and an additional absorption component due to dense neutral hydrogen gas clouds proximate to the galaxy, and we derive the redshift evolution of H i column density of the proximate clouds by calibrating the model using CANUCS JWST observations. The resulting total transmission curve resolves the photometric redshift bias at z > 7, an improvement that is robust to the choice of template-fitting code, template set, and photometric catalog used. The new attenuation model can be easily implemented in existing template-fitting codes and significantly improves the photometric redshift performance in the EoR.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766446","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}

{"title":"Space Weathering Properties of Chang’e-6 Soils and Implication for Regolith Evolution of Young Lunar Maria","authors":"Xuejin Lu, Jian Chen, Haijun Cao, Changqing Liu, Ziyi Jia, Chengxiang Yin, Tianwei Wang, Xiaohui Fu, Le Qiao, Xiaojia Zeng, Jiang Zhang and Zongcheng Ling","doi":"10.3847/2041-8213/adbffc","DOIUrl":"https://doi.org/10.3847/2041-8213/adbffc","url":null,"abstract":"Lunar soil samples from young maria (formed <3.0 billion years ago (Ga)) preserve key records of recent space weathering history in the Earth–Moon system. China’s Chang’e-6 mission returned the first farside soil samples from a young mare (∼2.8 Ga) at the northeastern South Pole–Aitken basin. We present preliminary results on the space weathering properties of the Chang’e-6 soils. The glassy agglutinate content in the Chang’e-6 soils is approximately 30%, significantly lower than the 50%–70% observed in the mature Apollo soils from older maria (>3.0 Ga) and higher than the ∼21% found in the Chang’e-5 soils from younger mare (∼2.0 Ga). However, our spectroscopic study reveals that the Chang’e-6 soils are well developed, with high maturity, weak absorption, and a red-sloped continuum, similar to the characteristics of the mature soils from the Apollo and Chang’e-5 landing sites. Orbital observations indicate more mature surface than in the returned samples from young mare regions, likely due to the destruction of an optically mature veneer by spacecraft. The optically mature veneer reveals deficiencies in remote sensing and emphasizes the importance of sample return missions. The thinner optically mature veneer and lower abundance of glassy agglutinate in younger maria suggest reduced gardening cycles and changes in impactor properties (such as rate and size) after 3.0 Ga. This is important for understanding how the relative contributions of space weathering agents change over time and the evolution of impactors in the inner solar system.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766444","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}

{"title":"The Cosmic Evolution Early Release Science Survey (CEERS)","authors":"Steven L. Finkelstein, Micaela B. Bagley, Pablo Arrabal Haro, Mark Dickinson, Henry C. Ferguson, Jeyhan S. Kartaltepe, Dale D. Kocevski, Anton M. Koekemoer, Jennifer M. Lotz, Casey Papovich, Pablo G. Pérez-González, Nor Pirzkal, Rachel S. Somerville, Jonathan R. Trump, Guang Yang, L. Y. Aaron Yung, Adriano Fontana, Andrea Grazian, Norman A. Grogin, Lisa J. Kewley, Allison Kirkpatrick, Rebecca L. Larson, Laura Pentericci, Swara Ravindranath, Stephen M. Wilkins, Omar Almaini, Ricardo O. Amorín, Guillermo Barro, Rachana Bhatawdekar, Laura Bisigello, Madisyn Brooks, Véronique Buat, Fernando Buitrago, Denis Burgarella, Antonello Calabrò, Marco Castellano, Yingjie Cheng, Nikko J. Cleri, Justin W. Cole, M. C. Cooper, Olivia R. Cooper, Luca Costantin, Isa G. Cox, Darren Croton, Emanuele Daddi, Kelcey Davis, Avishai Dekel, David Elbaz, Vital Fernández, Seiji Fujimoto, Giovanni Gandolfi, Jonathan P. Gardner, Eric Gawiser, Mauro Giavalisco, Carlos Gómez-Guijarro, Yuchen Guo, Ansh R. Gup..","doi":"10.3847/2041-8213/adbbd3","DOIUrl":"https://doi.org/10.3847/2041-8213/adbbd3","url":null,"abstract":"We present the Cosmic Evolution Early Release Science (CEERS) Survey, a 77.2 hr Director’s Discretionary Early Release Science Program. CEERS demonstrates, tests, and validates efficient extragalactic surveys using coordinated, overlapping parallel observations with the JWST instrument suite, including NIRCam and MIRI imaging, NIRSpec low- (R ∼ 100) and medium- (R ∼ 1000) resolution spectroscopy, and NIRCam slitless grism (R ∼ 1500) spectroscopy. CEERS targets the Hubble Space Telescope–observed region of the Extended Groth Strip field, supported by a rich set of multiwavelength data. CEERS facilitated immediate community science in both of the extragalactic core JWST science drivers “First Light” and “Galaxy Assembly,” including: (1) the discovery and characterization of large samples of galaxies at z ≳ 10 from ∼90 arcmin2 of NIRCam imaging, constraining their abundance and physical nature; (2) deep spectra of >1000 galaxies, including dozens of galaxies at 6 < z < 10, enabling redshift measurements and constraints on the physical conditions of star formation and black hole growth via line diagnostics; (3) quantifying the first bulge, bar, and disk structures at z > 3; and (4) characterizing galaxy mid-IR emission with MIRI to study dust-obscured star formation and supermassive black hole growth at z ∼ 1–3. As a legacy product for the community, the CEERS team has provided several data releases, accompanied by detailed notes on the data reduction procedures and notebooks to aid in reproducibility. In addition to an overview of the survey and the quality of the data, we provide science highlights from the first two years with CEERS data.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"216 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775702","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}