The Astrophysical Journal最新文献

{"title":"Evidence for a Link between Turbulence and the Generation of Ion Cyclotron Waves via the Helicity Barrier Effect in the Solar Wind","authors":"Utsav Panchal, Robert T. Wicks and Julia E. Stawarz","doi":"10.3847/1538-4357/adbfff","DOIUrl":"https://doi.org/10.3847/1538-4357/adbfff","url":null,"abstract":"The dissipation and heating of collisionless plasma in the inner heliosphere is a significant unresolved problem in space physics. The helicity barrier theory suggests a possible mechanism for these processes, but it requires validation through analysis of spacecraft data. We assess the validity of the parameter regime associated with the helicity barrier in the solar wind over a range of heliocentric distances using Parker Solar Probe and Solar Orbiter. We use the Politano–Pouquet law to estimate the energy and cross helicity cascade rates in the solar wind and compare the values to radial distance, the polarization, and prevalence of ion cyclotron waves. We find that the amplitude and prevalence of left-hand-polarized waves in the solar wind is directly correlated with the total energy and the cross-helicity cascade rate of the turbulence. Our measurements are consistent with the helicity barrier being active in all solar wind intervals that we study, and we demonstrate the uncertainty in calculating energy and the cross-helicity cascade rates in this study.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143841024","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":"Probing Solar Modulation of AMS-02 Time-dependent D, 3He, and 4He Fluxes with Modified Force-field Approximation Models","authors":"Cheng-Rui Zhu and Mei-Juan Wang","doi":"10.3847/1538-4357/adc12c","DOIUrl":"https://doi.org/10.3847/1538-4357/adc12c","url":null,"abstract":"The AMS-02 experiment recently published time-dependent fluxes of deuterons (D) from 2011 May to 2021 April, divided into 33 periods of four Bartels rotations each. These temporal structures are associated with solar modulation. In this study, three modified force-field approximations (FFAs) are employed to examine the long-term behavior of cosmic-ray isotopes such as D, 3He, and 4He, as well as the ratios D/3He and 3He/4He. The solar modulation potential is rigidity dependent for these modified FFA models. Due to the unknown local interstellar spectrum (LIS) for these isotopes, we utilize the non-LIS method for solar modulation. By fitting to the AMS-02 time-dependent fluxes, we derive the solar modulation parameters. Our findings prove the assumption in literature that all isotopes can be fitted using the same solar modulation parameters, and it is shown that the modified FFA models provide valid parameterization for solar modulation. Based on these, we forecast the daily fluxes of D, 3He, and 4He from 2011 to 2020.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143841069","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 All-sky Impact of the LMC on the Milky Way Circumgalactic Medium","authors":"Christopher Carr, Greg L. Bryan, Nicolás Garavito-Camargo, Gurtina Besla, David J. Setton, Kathryn V. Johnston and Kung-Yi Su","doi":"10.3847/1538-4357/adbf1d","DOIUrl":"https://doi.org/10.3847/1538-4357/adbf1d","url":null,"abstract":"The first infall of the LMC into the Milky Way (MW) represents a large and recent disruption to the MW circumgalactic medium (CGM). In this work, we use idealized, hydrodynamical simulations of an MW-like CGM embedded in a dark matter halo with an infalling LMC-like satellite initialized with its own CGM to understand how the encounter is shaping the global physical and kinematic properties of the MW CGM. First, we find that the LMC drives order-unity enhancements in MW CGM density, temperature, and pressure due to a shock from the supersonic CGM–CGM collision. The resulting shock front extends from the LMC to beyond ∼R200,MW, amplifying column densities, X-ray brightness, thermal Sunyaev–Zeldovich distortion, and potentially synchrotron emission from cosmic rays over large angular scales across the southern hemisphere. Second, the MW’s reflex motion relative to its outer halo induces a dipole in CGM radial velocities, with vR ± 30–50 km s−1 at R > 50 kpc in the northern and southern hemispheres, respectively, consistent with measurements in the stellar halo. Finally, ram pressure strips most of the LMC’s CGM, leaving ∼108−9M⊙ warm ionized gas along the past orbit of the LMC, moving at high radial and/or tangential velocities ∼50–100 kpc from the MW. Massive satellites like the LMC leave their mark on the CGM structure of their host galaxies, and signatures of such interactions may be observable in key all-sky tracers of the MW CGM and those of other massive galaxies.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"56 36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836964","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":"CY Aquarii: A Triple System with Twin Companions","authors":"Ming Lian, 茗 连, Jia-Shu Niu, 家树 牛, Hui-Fang Xue and 会芳 薛","doi":"10.3847/1538-4357/adc376","DOIUrl":"https://doi.org/10.3847/1538-4357/adc376","url":null,"abstract":"In this study, we conducted a comprehensive analysis of the SX Phoenicis (SX Phe) type star CY Aquarii (CY Aqr). Our investigation included a detailed O − C analysis based on a 90 yr observational data set, augmented by 1367 newly determined times of maximum light. The O − C diagram reveals that (i) the primary star of CY Aqr exhibits a linear period variation rate of (1/P0)(dP/dt) = (2.132 ± 0.002) × 10−8 yr−1 for its dominant pulsation mode; (ii) the primary star is disturbed by two companions and part of a triple system; (iii) Companion A has an orbital period of approximately 60.2 yr and Companion B has an orbital period of approximately 50.8 yr. It is highly probable that both Companion A and B are white dwarfs, with Companion A’s elliptical orbit displaying an eccentricity of e = 0.139 ± 0.002, which is the lowest confirmed value in similar binary and triple systems to date. Most notably, Companion A and B have masses that are identical within the uncertainties, with a mass ratio exceeding 0.99. Whether this is considered a coincidental event or the result of an underlying mechanism, CY Aqr is an exceptionally rare case that broadens our understanding of multiple star systems and offers a unique opportunity to delve into the enigmatic evolutionary histories of such configurations. Further intriguing characteristics of this system warrant investigation in future studies, based on additional observational data.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836989","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":"Proper Motion and Natal Kick in the Galactic Black Hole X-Ray Binary AT2019wey","authors":"Lang Cui, Pengfei Jiang, Tao An, Hongmin Cao, Ning Chang, Giulia Migliori, Marcello Giroletti, Sándor Frey, Jun Yang, Krisztina É. Gabányi, Xiaoyu Hong and Wenda Zhang","doi":"10.3847/1538-4357/adc0f7","DOIUrl":"https://doi.org/10.3847/1538-4357/adc0f7","url":null,"abstract":"Understanding the formation mechanisms of stellar-mass black hole X-ray binaries (BHXBs) remains a fundamental challenge in astrophysics. The natal kick velocities imparted during black hole (BH) formation provide crucial constraints on these formation channels. In this work, we present a new-epoch very long baseline interferometry (VLBI) observation of the Galactic BHXB AT2019wey carried out in 2023. Combining with archival VLBI data from 2020, we successfully measure the proper motion of AT2019wey over a 3 yr timescale, namely, 0.78 ± 0.12 mas yr−1 in R.A. and −0.42 ± 0.07 mas yr−1 in decl. Employing the measured proper motion, we estimate its peculiar velocity and the potential kick velocity (PKV) through Monte Carlo simulations, incorporating uncertainties of its distance and radial velocity. The estimated PKV distributions and height above the Galactic plane suggest that AT2019wey’s BH likely formed through a supernova explosion rather than direct collapse.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143837165","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":"Minifilament Eruptions as the Last Straw to Break the Equilibrium of a Giant Solar Filament","authors":"Hechao Chen, Hui Tian, Quanhao Zhang, Chuan Li, Chun Xia, Xianyong Bai, Zhenyong Hou, Kaifan Ji, Yuanyong Deng, Xiao Yang and Ziyao Hu","doi":"10.3847/1538-4357/adc12a","DOIUrl":"https://doi.org/10.3847/1538-4357/adc12a","url":null,"abstract":"Filament eruptions are magnetically driven violent explosions commonly observed on the Sun and late-type stars, sometimes leading to monster coronal mass ejections that directly affect the nearby planets’ environments. More than a century of research on solar filaments suggests that the slow evolution of photospheric magnetic fields plays a decisive role in initiating filament eruptions, but the underlying mechanism remains unclear. Using high-resolution observations from the Chinese Hα Solar Explorer, the Solar Upper Transition Region Imager, and the Solar Dynamics Observatory, we present direct evidence that a giant solar filament eruption is triggered by a series of minifilament eruptions occurring beneath it. These minifilaments, which are homologous to the giant filament but on a smaller tempo-spatial scale, sequently form and erupt due to extremely weak mutual flux disappearance of opposite-polarity photospheric magnetic fields. Through multifold magnetic interactions, these erupting minifilaments act as the last straw to break the force balance of the overlying giant filament and initiate its ultimate eruption. The results unveil a possible novel pathway for small-scale magnetic activities near the stellar surface to initiate spectacular filament eruptions, and provide new insight into the magnetic coupling of filament eruptions across different tempo-spatial scales.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836986","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":"Redshift Evolution of the X-Ray and Ultraviolet Luminosity Relation of Quasars: Calibrated Results from SNe Ia","authors":"Xiaolei Li, Ryan E. Keeley and Arman Shafieloo","doi":"10.3847/1538-4357/adc2fe","DOIUrl":"https://doi.org/10.3847/1538-4357/adc2fe","url":null,"abstract":"Quasars could serve as standard candles if the relation between their ultraviolet (UV) and X-ray luminosities can be accurately calibrated. Previously, we developed a model-independent method to calibrate quasar standard candles using the distance–redshift relation reconstructed from Type Ia supernovae (SNe Ia) at z < 2 using Gaussian process regression. Interestingly, we found that the calibrated quasar standard candle data set preferred a deviation from ΛCDM at redshifts above z > 2. One possible interpretation of these findings is that the calibration parameters of the quasar UV and X-ray luminosity relationship evolves with redshift. In order to test the redshift dependence of the quasar calibration in a model-independent manner, we divided the quasar sample whose redshift overlaps with the redshift coverage of Pantheon+ SNe Ia compilation into two subsamples: a low-redshift quasar subsample and a high-redshift quasar subsample. Assuming all the quasar samples are reliable, our results show that there is about a 4σ inconsistency between the quasar parameters inferred from the subsamples without considering evolution. This inconsistency suggests the possibility of considering redshift evolution for the relationship between the quasars’ UV and X-ray luminosities. We then test an explicit parameterization of the redshift evolution of the quasar calibration parameters via γ(z) = γ0 + γ1(1 + z) and β(z) = β0 + β1(1 + z). Combining this redshift-dependent calibration relationship with the distance–redshift relationship reconstructed from the Pantheon+ supernova compilation, we find the high-redshift subsample and low-redshift subsample become consistent at the 2σ level, which means that the parameterized form of γ(z) and β(z) works well at describing the evolution of the quasar calibration parameters.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143837199","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":"Unveiling the Dynamics and Genesis of Small-scale Fine-structure Loops in the Lower Solar Atmosphere","authors":"Annu Bura, Tanmoy Samanta, Alphonse C. Sterling, Yajie Chen, Jayant Joshi, Vasyl Yurchyshyn and Ronald L. Moore","doi":"10.3847/1538-4357/adc109","DOIUrl":"https://doi.org/10.3847/1538-4357/adc109","url":null,"abstract":"Recent high-resolution solar observations have unveiled the presence of small-scale loop-like structures in the lower solar atmosphere, often referred to as unresolved fine structures, low-lying loops, and miniature hot loops. These structures undergo rapid changes within minutes, and their formation mechanism has remained elusive. In this study, we conducted a comprehensive analysis of two small loops utilizing data from the Interface Region Imaging Spectrograph (IRIS), the Goode Solar Telescope (GST) at Big Bear Solar Observatory, and the Atmospheric Imaging Assembly and the Helioseismic Magnetic Imager on board the Solar Dynamics Observatory, aiming to elucidate the underlying process behind their formation. The GST observations revealed that these loops, with lengths of ∼3.5 Mm and heights of ∼1 Mm, manifest as bright emission structures in Hα wing images, particularly prominent in the red wing. IRIS observations showcased these loops in 1330 Å slit-jaw images, with transition region (TR) and chromospheric line spectra exhibiting significant enhancement and broadening above the loops, indicative of plasmoid-mediated reconnection during their formation. Additionally, we observed upward-erupting jets above these loops across various passbands. Furthermore, differential emission measurement analysis reveals an enhanced emission measure at the location of these loops, suggesting the presence of plasma exceeding 1 MK. Based on our observations, we propose that these loops and associated jets align with the minifilament eruption model. Our findings suggest a unified mechanism governing the formation of small-scale loops and jets akin to larger-scale X-ray jets.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143837167","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":"Spectroscopy of Supernova Remnants and Candidates in M31","authors":"Nelson Caldwell, John C. Raymond, Knox S. Long and Myung Gyoon Lee","doi":"10.3847/1538-4357/adbf98","DOIUrl":"https://doi.org/10.3847/1538-4357/adbf98","url":null,"abstract":"With a star formation rate of order 0.4 M⊙ yr−1, M31 should have a significant population of supernova remnants (SNRs) and, in fact, 156 SNRs and SNR candidates have been suggested by J. H. Lee & M. G. Lee, by searching for nebulae with elevated [S ii]/Hα ratios in narrowband images. Here, we use a combination of low- and high-resolution optical spectroscopy obtained with Hectospec on the MMT to characterize 152 of these nebulae. Of these candidates, we find 93 nebulae that have [S ii]/Hα ratios that exceed 0.4, the traditional ratio used to separate SNRs from H ii regions, strongly suggesting that at least these objects are SNRs. Our high-resolution spectroscopy reveals 108 nebulae that have velocity widths in Hα (full width at 20% peak flux) that exceed 50 km s−1, significantly larger than found in H ii regions. There are 72 objects that satisfy both tests. Here, we discuss the spectroscopic characteristics of all of the objects in our sample, and the likelihood that other objects in the sample of J. H. Lee & M. G. Lee are also SNRs, and we briefly consider confirmation by X-ray, radio, and UV observations. We also discuss several new candidates that have been identified serendipitously in the course of examining a large amount of archival Hectospec data.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143837163","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":"BEACON: JWST NIRCam Pure-parallel Imaging Survey. I. Survey Design and Initial Results","authors":"Takahiro Morishita, Charlotte A. Mason, Kimi C. Kreilgaard, Michele Trenti, Tommaso Treu, Benedetta Vulcani, Yechi Zhang, Abdurro’uf, Anahita Alavi, Hakim Atek, Yannick Bahé, Maruša Bradač, Larry D. Bradley, Andrew J. Bunker, Dan Coe, James Colbert, Viola Gelli, Matthew J. Hayes, Tucker Jones, Tadayuki Kodama, Nicha Leethochawalit, Zhaoran Liu, Matthew A. Malkan, Vihang Mehta, Benjamin Metha, Andrew B. Newman, Marc Rafelski, Guido Roberts-Borsani, Michael J. Rutkowski, Claudia Scarlata, Massimo Stiavelli, Ryo A. Sutanto, Kosuke Takahashi, Harry I. Teplitz and Xin Wang","doi":"10.3847/1538-4357/adbbdc","DOIUrl":"https://doi.org/10.3847/1538-4357/adbbdc","url":null,"abstract":"We introduce the Bias-free Extragalactic Analysis for Cosmic Origins with NIRCam (BEACON) survey, a JWST Cycle 2 program allocated up to 600 pure-parallel hours of observations. BEACON explores high-latitude areas of the sky with JWST/NIRCam over ∼100 independent sight lines, totaling ∼0.3 deg2, reaching a median F444W depth of ≈28.2 AB mag (5σ). Based on existing JWST observations in legacy fields, we estimate that BEACON will photometrically identify 25–150 galaxies at z > 10 and 500–1000 at z ∼ 7–10 uniquely enabled by an efficient multiple filter configuration spanning 0.9–5.0 μm. The expected sample size of z > 10 galaxies will allow us to obtain robust number density estimates and to discriminate between different models of early star formation. In this paper, we present an overview of the survey design and initial results using the first 19 fields. We present 129 galaxy candidates at z ≳7 identified in those fields, including 11 galaxies at z ≳10 and several UV-luminous (MUV < −21 mag) galaxies at z ∼ 8. The number densities of z < 13 galaxies inferred from the initial fields are overall consistent with those in the literature. Despite reaching a considerably large volume (∼105 Mpc3), however, we find no galaxy candidates at z > 13, providing us with a complimentary insight into early galaxy evolution with minimal cosmic variance. We publish imaging and catalog data products for these initial fields. Upon survey completion, all BEACON data will be coherently processed and distributed to the community along with catalogs for redshift and other physical quantities.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143841074","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}