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GWSkyNet. II. A Refined Machine-learning Pipeline for Real-time Classification of Public Gravitational Wave Alerts Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Man Leong Chan, Jess McIver, Ashish Mahabal, Cody Messick, Daryl Haggard, Nayyer Raza, Yannick Lecoeuche, Patrick J. Sutton, Becca Ewing, Francesco Di Renzo, Miriam Cabero, Raymond Ng, Michael W. Coughlin, Shaon Ghosh and Patrick Godwin
Electromagnetic follow-up observations of gravitational wave events offer critical insights and provide significant scientific gain from this new class of astrophysical transients. Accurate identification of gravitational wave candidates and rapid release of sky localization information are crucial for the success of these electromagnetic follow-up observations. However, searches for gravitational
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The NANOGrav 15 yr Data Set: Chromatic Gaussian Process Noise Models for Six Pulsars Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Bjorn Larsen, Chiara M. F. Mingarelli, Jeffrey S. Hazboun, Aurélien Chalumeau, Deborah C. Good, Joseph Simon, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Paul R. Brook, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels
Pulsar timing arrays (PTAs) are designed to detect low-frequency gravitational waves (GWs). GWs induce achromatic signals in PTA data, meaning that the timing delays do not depend on radio frequency. However, pulse arrival times are also affected by radio-frequency-dependent “chromatic” noise from sources such as dispersion measure (DM) and scattering delay variations. Furthermore, the characterization
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Unraveling the Origins of an Extreme Solar Eruptive Event with Hard X-Ray Imaging Spectroscopy Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Juliana T. Vievering, Angelos Vourlidas and Säm Krucker
Hard X-ray (HXR) observations are crucial for understanding the initiation and evolution of solar eruptive events, as they provide a key signature of flare-accelerated electrons and heated plasma. The potential of high-cadence HXR imaging for deciphering the erupting structure, however, has not received adequate attention in an era of extreme ultraviolet (EUV) imaging abundance. An extreme solar eruptive
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Novel Insights on the Dust Distribution in the Zodiacal Dust Cloud from PSP/WISPR Observations at Large Elongations Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Guillermo Stenborg, Angelos Vourlidas, Evangelos Paouris and Russell A. Howard
The Wide-Field Imager for Solar Probe (WISPR) on the Parker Solar Probe (PSP) mission maps the brightness produced by the zodiacal dust cloud (ZDC) from an historically unprecedented viewpoint. The brightness results from the scattering of photospheric light by dust particles in the ZDC, and is called zodiacal light (ZL). We exploit the PSP nominal science encounters in orbits 10 through 16 for an
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Solar Rotation and Activity for Cycle 24 from SDO/AIA Observations Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Zahra Shokri, Nasibe Alipour and Hossein Safari
Differential rotation plays a crucial role in the dynamics of the Sun. We study the solar rotation and its correlation with solar activity by applying a modified machine learning algorithm to identify and track coronal bright points (CBPs) from the Solar Dynamics Observatory/Atmospheric Imaging Assembly observations at 193 Å during cycle 24. For more than 321,440 CBPs, the sidereal and meridional velocities
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Deeper, Sharper, Faster: Application of Efficient Transformer to Galaxy Image Restoration Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Hyosun Park, Yongsik Jo, Seokun Kang, Taehwan Kim and M. James Jee
The Transformer architecture has revolutionized the field of deep learning over the past several years in diverse areas, including natural language processing, code generation, image recognition, and time-series forecasting. We propose to apply Zamir et al.'s efficient transformer to perform deconvolution and denoising to enhance astronomical images. We conducted experiments using pairs of high-quality
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Revealing the Production Mechanism of High-energy Neutrinos from NGC 1068 Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Abhishek Das, B. Theodore Zhang and Kohta Murase
The detection of high-energy neutrino signals from the nearby Seyfert galaxy NGC 1068 provides us with an opportunity to study nonthermal processes near the center of supermassive black holes. Using the IceCube and latest Fermi-LAT data, we present general multimessenger constraints on the energetics of cosmic rays and the size of neutrino emission regions. In the photohadronic scenario, the required
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Timing and Scintillation Studies of Pulsars in Globular Cluster M3 (NGC 5272) with FAST Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Baoda Li, Li-yun Zhang, Jumei Yao, Dejiang Yin, Ralph P. Eatough, Minghui Li, Yifeng Li, Yujie Lian, Yu Pan, Yinfeng Dai, Yaowei Li, Xingnan Zhang, Tianhao Su, Yuxiao Wu, Tong Liu, Kuo Liu, Lin Wang, Lei Qian and Zhichen Pan
We present the phase-connected timing solutions of all five pulsars in globular cluster M3 (NGC 5272), namely PSRs M3A to F (PSRs J1342+2822A to F), with the exception of PSR M3C, from FAST archival data. In these timing solutions, those of PSRs M3E and F are obtained for the first time. We find that PSRs M3E and F have low-mass companions and are in circular orbits with periods of 7.1 and 3.0 days
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The K s -band Luminosity Function of the Rich Cluster VC04 in the Vela Supercluster Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 N. Hatamkhani, R. C. Kraan-Korteweg, S. L. Blyth and R. E. Skelton
To learn more about the properties of the Vela Supercluster (VSCL), located behind the Milky Way at cz ∼ 18,000 km s−1, we determine the Ks-band luminosity function (LF) of VC04, the richest known galaxy cluster in the VSCL, and two other VSCL clusters (VC02 and VC08). The galaxy sample is based on NIR observations that are complete to an extinction-corrected absolute magnitude of (∼2.ͫ5 below ), within
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Lyα Emission Line Profiles of Extreme [O iii]- emitting Galaxies at z ≳ 2: Implications for Lyα Visibility in the Reionization Era Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Mengtao Tang, Daniel P. Stark, Richard S. Ellis, Michael W. Topping, Charlotte Mason, Zhihui Li and Adèle Plat
JWST observations have recently begun delivering the first samples of Lyα velocity profile measurements at z > 6, opening a new window into the reionization process. Interpretation of z ≳ 6 line profiles is currently stunted by limitations in our knowledge of the intrinsic Lyα profile (before encountering the intergalactic medium (IGM)) of the galaxies that are common at z ≳ 6. To overcome this shortcoming
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Molecular Hydrogen Formation via Vibrational Excitation of Partially Superhydrogenated Pyrenes Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Frederik Doktor S. Simonsen, Rijutha Jaganathan, Julianna Palotás, Zeyuan Tang, Bjørk Hammer, Jos Oomens and Liv Hornekær
While polycyclic aromatic hydrocarbons (PAHs) are now accepted to be abundant in interstellar space, the abundance and influence of superhydrogenated PAHs (HPAHs) in the interstellar medium (ISM) are still under investigation. HPAHs may act as catalysts for or reactants in small-molecule formation via hydrogen abstraction reactions, H2 evaporation, and carbon skeleton fragmentation. Here, we present
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GRMHD Simulations of Accretion Structures with Different Angular Momentum Profiles Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Dilshodbek Bardiev, Yuhuan Wang, Martin Kološ and Bobomurat Ahmedov
In this article, we explore the dynamics of accretion structures encircling spherically symmetric black holes, comparing three accretion disk models with distinct angular momentum profiles: (i) the geometrically thin Keplerian disk, (ii) the Fishbone–Moncrief torus; and (iii) the Polish Doughnut. Employing general relativistic magnetohydrodynamics simulations with the High Accuracy Relativistic Magnetohydrodynamics
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Cold Filaments Formed in Hot Wake Flows Uplifted by Active Galactic Nucleus Bubbles in Galaxy Clusters Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Xiaodong Duan and Fulai Guo
Multiwavelength observations indicate that the intracluster medium in some galaxy clusters contains cold filaments, while their formation mechanism remains debated. Using hydrodynamic simulations, we show that cold filaments could naturally condense out of the hot gaseous wake flows uplifted by jet-inflated active galactic nucleus (AGN) bubbles. Consistent with observations, the simulated filaments
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The Differences in the Origination and Properties of the Near-Earth Solar Wind between Solar Cycles 23 and 24 Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Xinzheng Shi, Hui Fu, Zhenghua Huang, Limei Yan, Chi Ma, Chenxi Huangfu, Hongqiang Song and Lidong Xia
The dependence of the sources and properties of the near-Earth solar wind on solar cycle activity is an important issue in solar and space physics. We use the improved “two-step” mapping procedure that takes into account the initial acceleration processes to trace the near-Earth solar winds back to their source regions from 1999–2020, covering solar cycles (SCs) 23 and 24. Then, the solar wind is categorized
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The Instability Mechanism of Compact Multiplanet Systems Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Caleb Lammers, Sam Hadden and Norman Murray
To improve our understanding of orbital instabilities in compact planetary systems, we compare suites of N-body simulations against numerical integrations of simplified dynamical models. We show that, surprisingly, dynamical models that account for small sets of resonant interactions between the planets can accurately recover N-body instability times. This points toward a simple physical picture in
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Optically Thick Jet Base and Explanation of Edge Brightening in Active Galactic Nucleus Jets Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Mukesh Kumar Vyas and Asaf Pe’er
The jet cores in active galactic nuclei (AGNs) are resolved and found to harbor an edge-brightened structure where the jet base appears extended at the sides compared to its propagation axis. This peculiar phenomenon invites various explanations. We show that the photosphere of an optically thick jet base in AGNs is observed edge brightened if the jet Lorentz factor harbors an angular dependence. The
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Investigation of Phase Shift and Travel Time of Acoustic Waves in the Lower Solar Atmosphere Using Multiheight Velocities Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Hirdesh Kumar, Brajesh Kumar, Shibu K. Mathew, A. Raja Bayanna and S. P. Rajaguru
We report and discuss the phase shift and phase travel time of low-frequency (ν < 5.0 mHz) acoustic waves estimated within the photosphere and photosphere–chromosphere interface regions, utilizing multiheight velocities in the quiet Sun. The bisector method has been employed to estimate seven height velocities in the photosphere within the Fe i 6173 Å line scan, while nine height velocities are estimated
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Evaluating the Geoeffectiveness of Interplanetary Coronal Mass Ejections: Insights from a Support Vector Machine Approach with SHAP Value Analysis Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Yudong Ye, Jiajia Liu, Yongqiang Hao and Jun Cui
In this study, we compiled a data set of 510 interplanetary coronal mass ejections (ICME) events from 1996–2023 and trained a radial basis function support vector machine (RBF-SVM) model to investigate the geoeffectiveness of ICMEs and its dependence on the solar wind conditions observed at 1 au. The model demonstrates high performance in classifying geomagnetic storm intensities at specific Disturbance
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Transverse Oscillations and Kelvin–Helmholtz Instability in Curved Arcade Loops with Siphon Flows Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Igor Lopin
The effect of plasma flow in curved arcade loops on transverse waves and oscillations is examined analytically. The model under study is a semicircular magnetic slab with finite transverse extensions and a mass flow inside, in the zero-β plasma approximation. It is found that in the quasi-perpendicular propagation limit, the model supports two fast surface modes: one with higher (FSW+) and another
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Lyα Imaging around the Hyperluminous Dust-obscured Quasar W2246–0526 at z = 4.6 Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Yibin Luo, 毅彬 罗, Lulu Fan, 璐璐 范, Yongming Liang, 永明 梁, Weida Hu, 维达 胡, Junxian Wang, 俊贤 王, Zhen-ya Zheng, 振亚 郑, Zheyu Lin, 哲宇 林, Bojun Tao, 柏钧 陶, Zesen Lin, 泽森 林, Minxuan Cai, Mengqiu Huang, 梦秋 黄, Zhen Wan, 振 宛, Yongling Tang and 永灵 唐
Hot dust-obscured galaxies (hot DOGs) are a population of hyperluminous, heavily obscured quasars discovered by the Wide-field Infrared Survey Explorer all-sky survey at high redshift. Observations suggested the growth of these galaxies may be driven by mergers. Previous environmental studies have statistically shown hot DOGs may reside in dense regions. Here we use the Very Large Telescope narrowband
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Al2O Photochemistry Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Tarek Trabelsi and Joseph S. Francisco
The chemistry within the interstellar medium (ISM) is notably influenced by the interplay between kinetics and photochemical processes, which play significant roles in both the formation and destruction of molecular species. This study focuses on theoretical investigations of Al2O photochemistry, aiming to elucidate the mechanisms underlying the production of AlO and Al in the VY-CMa star. Utilizing
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Phase-resolved Deadtime of the Crab Pulsar Using IXPE Data Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 M. Vivekanand
After receiving an X-ray photon, an X-ray detector is not operational for a duration known as deadtime. It is detector specific and its effect on the data depends upon the luminosity of the source. It reduces the observed photon count rate in comparison to the expected one. In periodic sources such as the Crab pulsar, it can distort the folded light curve (FLC). An undistorted FLC of the Crab pulsar
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On the Formation and Detectability of H2CNCN and Its Progenitors Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Ryan C. Fortenberry and Vincent J. Esposito
New highly exothermic formation pathways incorporating both thermodynamic and kinetic control for the newly astronomically detected H2CNCN molecule are paired with extremely accurate quantum chemical rovibrational spectroscopic computations. The reactions between astronomically known CH2CN/CH2CCH + HNCN follow effectively identical pathways and proceed through stable intermediates and over deeply submerged
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Do All the Quasars and High-excitation Radio Galaxies (HERGs) in the 3CRR Catalog Contain a Magnetically Arrested Disk (MAD)? Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Shuang-Liang Li, Wenwen Zuo and Xinwu Cao
Based on the magnetization, an accretion disk with a large-scale magnetic field can be separated into either standard and normal evolution or magnetically arrested disk (MAD), which are difficult to identify from observations. It is still unclear whether all the radio-loud active galactic nuclei (RLAGNs) with a thin disk and strong radio emissions contain a MAD. We investigate this issue by utilizing
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Cyclical Period Changes in Cataclysmic Variables: A Statistical Study Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Leandro Souza and Raymundo Baptista
We report the results of a statistical study of cyclical period changes in cataclysmic variables (CVs). Assuming the third-body hypothesis as the cause of period changes, we estimate the third-body mass, m3, and its separation from the binary, a3, for 21 CVs showing cyclical period changes from well-sampled observed-minus-calculated diagrams covering more than a decade of observations. The inferred
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TeV Analysis of a Source-rich Region with the HAWC Observatory: Is HESS J1809-193 a Potential Hadronic PeVatron? Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, R. Babu, E. Belmont-Moreno, A. Bernal, M. Breuhaus, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, J. Cotzomi, E. De la Fuente, D. Depaoli, N. Di Lalla, R. Diaz Hernandez, B. L. Dingus, M. A. DuVernois, C. Espinoza, K. L. Fan, K. Fang, B. Fick, N. Fraija, J. A. García-González, F. Garfias, A. Gonzalez Muñoz
HESS J1809-193 is an unidentified TeV source, first detected by the High Energy Stereoscopic System (H.E.S.S.) collaboration. The emission originates in a source-rich region that includes several supernova remnants (SNRs) and pulsars including SNR G11.1+0.1, SNR G11.0-0.0, and the young radio pulsar PSR J1809-1917. Originally classified as a pulsar wind nebula candidate, recent studies show the peak
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Observational Characteristics of Circumplanetary-mass-object Disks in the Era of James Webb Space Telescope Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Xilei Sun, 锡磊 孙, Pinghui Huang, 平辉 黄, Ruobing Dong, 若冰 董, Shang-Fei Liu and 尚飞 刘
Recent observations have confirmed circumplanetary disks (CPDs) embedded in parental protoplanetary disks (PPDs). On the other hand, planetary-mass companions and planetary-mass objects (PMOs) are likely to harbor their own accretion disks. Unlike PPDs, CPDs and other disks around planet analogs are generally too compact to be spatially resolved by current instrumentation. In this study, we generate
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High-redshift Merger Model for Low-frequency Gravitational Wave Background Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Zhao-Feng Wu and Dimitrios Giannios
In 2023, the Pulsar Timing Array Collaborations announced the discovery of a gravitational wave background (GWB), predominantly attributed to supermassive black hole binary (SMBHB) mergers. However, the detected GWB is several times stronger than the default value expected from galactic observations at low and moderate redshifts. Recent findings by the James Webb Space Telescope have unveiled a substantial
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Integrated Study of X-Ray Spectrum and Time Lags for HBL Mrk 421 within the Framework of the Multiple-zone Leptonic Model Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Wen Hu, 文 胡, Jia-Lai Kang, 嘉来 康, Zhen-Yi Cai, 振翼 蔡, Jun-Xian Wang, 俊贤 王, Zhen-Bo Su, 镇波 苏, Guang-Cheng Xiao and 广成 肖
We present the timing analysis of 10 archived XMM-Newton observations with an exposure of >40 ks of Markarian 421. Mrk 421 is the brightest high-frequency-peaked BL Lac object emitting in X-rays produced by electrons accelerated in the innermost regions of a relativistic jet pointing toward us. For each observation, we construct averaged X-ray spectra in 0.5–10 keV band, as well as 100 s binned light
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Accretion Geometry of GX 339–4 in the Hard State: AstroSat View Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Swadesh Chand, Gulab C. Dewangan, Andrzej A. Zdziarski, Dipankar Bhattacharya, N. P. S. Mithun and Santosh V. Vadawale
We perform broadband (0.7–100 keV) spectral analysis of five hard state observations of the low-mass black hole X-ray binary GX 339–4 taken by AstroSat during the rising phase of three outbursts from 2019 to 2022. We find that the outburst in 2021 was the only successful/full outburst, while the source was unable to make the transition to the soft state during the other two outbursts in 2019 and 2022
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The Massive and Distant Clusters of WISE Survey 2: A Stacking Analysis Investigating the Evolution of Star Formation Rates and Stellar Masses in Groups and Clusters Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 A. Trudeau, Anthony H. Gonzalez, K. Thongkham, Kyoung-Soo Lee, Stacey Alberts, M. Brodwin, Thomas Connor, Peter R. M. Eisenhardt, Emily Moravec, Eshwar Puvvada, S. A. Stanford
The evolution of galaxies depends on their masses and local environments; understanding when and how environmental quenching starts to operate remains a challenge. Furthermore, studies of the high-redshift regime have been limited to massive cluster members, owing to sensitivity limits or small fields of view when the sensitivity is sufficient, intrinsically biasing the picture of cluster evolution
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Planck Dust Polarization Power Spectra Are Consistent with Strongly Supersonic Turbulence Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Kye A. Stalpes, David C. Collins, Kevin M. Huffenberger
The polarization of the cosmic microwave background is rich in information but obscured by foreground emission from the Milky Way’s interstellar medium (ISM). To uncover relationships between the underlying turbulent ISM and the foreground power spectra, we simulated a suite of driven, magnetized, turbulent models of the ISM, varying the fluid properties via the sonic Mach number, MS , and magnetic
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The Nearly Universal Disk Galaxy Rotation Curve Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Raj Patel, Nikhil Arora, Stéphane Courteau, Connor Stone, Matthew Frosst, Lawrence Widrow
The universal rotation curve (URC) of disk galaxies was originally proposed to predict the shape and amplitude of any rotation curve (RC) based solely on photometric data. Here, the URC is investigated with an extensive set of spatially resolved RCs drawn from the PROBES-I, PROBES-II, and MaNGA databases with matching multiband surface brightness profiles from the DESI-LIS and Wide-Field Infrared Survey
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Statistical Distributions of Plasma Density and Pressure in the Jovian Plasma Sheet Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Haobo Fu, Chao Yue, Qianli Ma, M. Blanc, Q.-G. Zong, Xuzhi Zhou, B. H. Mauk, Zhiyang Liu
The Jovian plasma sheet is a key region of the Jovian magnetosphere populated by a mix of warm and hot plasma. It is the main channel for radial transport of mass and energy in the Jovian magnetosphere and provides a favorable environment for magnetic reconnection and wave–particle interactions although the understanding of its plasma properties is incomplete. This study combines observations from
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Simultaneous Far-ultraviolet and Near-ultraviolet Observations of T Tauri Stars with UVIT/AstroSat: Probing the Accretion Process in Young Stars Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Prasanta K. Nayak, Mayank Narang, P. Manoj, Uma Gorti, Annapurni Subramaniam, Nayana George, Chayan Mondal
We present results from simultaneous far-ultraviolet (FUV) and near-ultraviolet (NUV) observations of T Tauri stars (TTSs) in the Taurus molecular cloud with UVIT/AstroSat. This is the very first UVIT study of TTSs. From the spectral energy distribution of TTSs from FUV to IR, we show that classical TTSs (CTTSs) emit significantly higher UV excess compared to weak-line TTSs (WTTSs). The equivalent
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Radiation RMHD Accretion Flows around Spinning AGNs: A Comparative Study of MAD and SANE State Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Ramiz Aktar, Kuo-Chuan Pan, Toru Okuda
In our study, we examine a 2D radiation, relativistic, magnetohydrodynamics accretion flow around a spinning supermassive black hole. We begin by setting an initial equilibrium torus around the black hole, with an embedded initial magnetic field inside the torus. The strength of the initial magnetic field is determined by the plasma beta parameter, which is the ratio of the gas pressure to the magnetic
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Tracing Magnetic Fields with the Gradient Technique: Spatial Filtering Effect and Use of Interferometers Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Yue Hu, A. Lazarian
Probing magnetic fields in astrophysical environments is both important and challenging. The Gradient Technique (GT) is a new tool for tracing magnetic fields, rooted in the properties of magnetohydrodynamic (MHD) turbulence and turbulent magnetic reconnection. In this work, we examine the performance of GT when applied to synthetic synchrotron emission and spectroscopic data obtained from sub-Alfvénic
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Magnetic Fields in Ministarburst Complex Sgr B2 Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Xing Pan, Qizhou Zhang, Keping Qiu, Ramprasad Rao, Lingzhen Zeng, Xing Lu, Junhao Liu
We report the first arcsecond-resolution observations of the magnetic field in the ministarburst complex Sgr B2. SMA polarization observations revealed magnetic field morphology in three dense cores of Sgr B2 N(orth), M(ain), and S(outh). The total plane-of-sky magnetic field strengths in these cores are estimated to be 4.3–10.0 mG, 6.2–14.7 mG, and 1.9–4.5 mG derived from the angular dispersion function
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A Cyclic Spectroscopy Scintillation Study of PSR B1937+21. I. Demonstration of Improved Scintillometry Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Jacob E. Turner, Timothy Dolch, James M. Cordes, Stella K. Ocker, Daniel R. Stinebring, Shami Chatterjee, Maura A. McLaughlin, Victoria E. Catlett, Cody Jessup, Nathaniel Jones, Christopher Scheithauer
We use cyclic spectroscopy to perform high-frequency resolution analyses of multihour baseband Arecibo observations of the millisecond pulsar PSR B1937+21. This technique allows for the examination of scintillation features in far greater detail than is otherwise possible under most pulsar timing array observing setups. We measure scintillation bandwidths and timescales in each of eight subbands across
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Constraining the Number Density of the Accretion Disk Wind in Hercules X-1 Using Its Ionization Response to X-Ray Pulsations Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 P. Kosec, D. Rogantini, E. Kara, C. R. Canizares, A. C. Fabian, C. Pinto, I. Psaradaki, R. Staubert, D. J. Walton
X-ray binaries are known to launch powerful accretion disk winds that can have a significant impact on the binary systems and their surroundings. To quantify the impact and determine the launching mechanisms of these outflows, we need to measure the wind plasma number density, an important ingredient in the theoretical disk wind models. While X-ray spectroscopy is a crucial tool for understanding the
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Origin of the Twice-90° Rotations of the Polarization Angle in GRB 170114A and GRB 160821A Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Xu Wang, Mi-Xiang Lan, Qing-Wen Tang, Xue-Feng Wu, Zi-Gao Dai
The observed abrupt twice-90° rotations of the polarization angle (PA) in the prompt phase of gamma-ray bursts (GRBs) are difficult to understand within the current one-emitting-shell models. Here, we apply a model with multiple emitting shells to solve this new challenging problem. Two configurations of large-scale ordered magnetic fields in the shells are considered: toroidal and aligned. Together
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Constraining Cosmological Parameters Using the Splashback Radius of Galaxy Clusters Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Roan Haggar, Yuba Amoura, Charlie T. Mpetha, James E. Taylor, Kris Walker, Chris Power
Cosmological parameters such as ΩM and σ 8 can be measured indirectly using various methods, including galaxy cluster abundance and cosmic shear. These measurements constrain the composite parameter S 8, leading to degeneracy between ΩM and σ 8. However, some structural properties of galaxy clusters also correlate with cosmological parameters, due to their dependence on a cluster’s accretion history
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Reconstruction of the Dark Energy Scalar Field Potential by Gaussian Process Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Jing Niu, Kang Jiao, Peng He, Tong-Jie Zhang
Dark energy is believed to be responsible for the acceleration of the Universe. In this paper, we reconstruct the dark energy scalar field potential V(ϕ) using the Hubble parameter H(z) through Gaussian process analysis. Our goal is to investigate dark energy using various H(z) data sets and priors. We find that the selection of the prior and the H(z) data set significantly affects the reconstructed
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A Brown Dwarf Orbiting around the Planetary-nebula Central Binary KV Vel Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 S.-B. Qian, L.-Y. Zhu, F.-X. Li, L.-J. Li, Z.-T. Han, J.-J. He, L. Zang, L.-F. Chang, Q.-B. Sun, M.-Y. Li, H.-T. Zhang, F.-Z. Yan
KV Vel is a noneclipsing short-period (P = 0.3571 days) close binary containing a very hot subdwarf primary (77,000 K) and a cool low-mass secondary star (3400 K) that is located at the center of the planetary nebula DS 1. The changes in the orbital period of the close binary were analyzed based on 262 new times of light maximum together with those compiled from the literature. It is discovered that
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Laboratory Transition-rate Measurement of the Coronal Intercombination Line of Ar xv by Time-resolved Laser Spectroscopy Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Naoki Kimura, Yoshiki Miya, Daiki Ito, 0000-0001-6263-6563Priti4, Daiji Kato, Masaaki Baba, Susumu Kuma, Toshiyuki Azuma, Nobuyuki Nakamura
The extreme-ultraviolet emission line (424 Å) of the intercombination 1s 22s 2 1 S 0–1s 22s2p 3 P 1 transition of Ar xv can potentially characterize the electron temperature of astrophysical plasma. Various theoretical studies have investigated the intercombination transition rate, which is essential for the plasma diagnostics; however, experimental difficulties have prevented its measurement. We present
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STELLA Lightcurves of Energetic Pair-instability Supernovae in the Context of SN2018ibb Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 Chris Nagele, Hideyuki Umeda, Keiichi Maeda
SN2018ibb is a recently observed hydrogen-poor superluminous supernova that appears to be powered by the decay of 30 M ⊙ of radioactive nickel. This supernova has been suggested to show hybrid signatures of a pair-instability supernova and an interacting supernova. In a previous paper, we found that rotating, metal-enriched pair-instability supernova progenitors appeared to check both of these boxes
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Local Transition of Electron Pitch Angle Distribution within Flux Pileup Region behind Dipolarization Front Astrophys. J. (IF 4.8) Pub Date : 2024-08-22 X. N. Xing, C. M. Liu, J. B. Cao, Y. Y. Liu, B. N. Zhao
Dipolarization fronts (DFs), earthward-propagating magnetic transients with a strong magnetic field, are important regions favorable for energetic electron acceleration in the magnetotail. The DF-driven electron acceleration usually generates coherent pitch angle distributions (PADs) inside flux pileup regions (FPRs), i.e., strong magnetic field regions behind the DFs, such as pancake, butterfly, and
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The Zwicky Transient Facility Bright Transient Survey. III. BTSbot: Automated Identification and Follow-up of Bright Transients with Deep Learning Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Nabeel Rehemtulla, Adam A. Miller, Theophile Jegou Du Laz, Michael W. Coughlin, Christoffer Fremling, Daniel A. Perley, Yu-Jing Qin, Jesper Sollerman, Ashish A. Mahabal, Russ R. Laher, Reed Riddle, Ben Rusholme, Shrinivas R. Kulkarni
The Bright Transient Survey (BTS) aims to obtain a classification spectrum for all bright (m peak ≤ 18.5 mag) extragalactic transients found in the Zwicky Transient Facility (ZTF) public survey. BTS critically relies on visual inspection (“scanning”) to select targets for spectroscopic follow-up, which, while effective, has required a significant time investment over the past ∼5 yr of ZTF operations
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Concurrent Particle Acceleration and Pitch-angle Anisotropy Driven by Magnetic Reconnection: Ion-electron Plasmas Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Luca Comisso
Particle acceleration and pitch-angle anisotropy resulting from magnetic reconnection are investigated in highly magnetized ion-electron plasmas. By means of fully kinetic particle-in-cell simulations, we demonstrate that magnetic reconnection generates anisotropic particle distributions fs∣cosα∣,ε , characterized by broken power laws in the particle energy spectrum f s (ε) ∝ ε −p and pitch angle 〈sin2α〉∝εm
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The Ultraviolet Luminosity Function at 0.6 < z < 1 from UVCANDELS Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Lei Sun, Xin Wang, Harry I. Teplitz, Vihang Mehta, Anahita Alavi, Marc Rafelski, Rogier A. Windhorst, Claudia Scarlata, Jonathan P. Gardner, Brent M. Smith, Ben Sunnquist, Laura Prichard, Yingjie Cheng, Norman Grogin, Nimish P. Hathi, Matthew Hayes, Anton M. Koekemoer, Bahram Mobasher, Kalina V. Nedkova, Robert O’Connell, Brant Robertson, Sina Taamoli, L. Y. Aaron Yung, Gabriel Brammer, James Colbert
UVCANDELS is a Hubble Space Telescope Cycle-26 Treasury Program awarded 164 orbits of primary ultraviolet (UV) F275W imaging and coordinated parallel optical F435W imaging in four CANDELS fields—GOODS-N, GOODS-S, EGS, and COSMOS—covering a total area of ∼426 arcmin2. This is ∼2.7 times larger than the area covered by previous deep-field space UV data combined, reaching a depth of about 27 and 28 ABmag
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Flaring Stars in a Nontargeted Millimeter-wave Survey with SPT-3G Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 C. Tandoi, S. Guns, A. Foster, P. A. R. Ade, A. J. Anderson, B. Ansarinejad, M. Archipley, L. Balkenhol, K. Benabed, A. N. Bender, B. A. Benson, F. Bianchini, L. E. Bleem, F. R. Bouchet, L. Bryant, E. Camphuis, J. E. Carlstrom, T. W. Cecil, C. L. Chang, P. Chaubal, P. M. Chichura, T.-L. Chou, A. Coerver, T. M. Crawford, A. Cukierman, C. Daley, T. de Haan, K. R. Dibert, M. A. Dobbs, A. Doussot, D. Dutcher
We present a flare star catalog from 4 yr of nontargeted millimeter-wave survey data from the South Pole Telescope (SPT). The data were taken with the SPT-3G camera and cover a 1500 deg2 region of the sky from 20h40m0s to 3h20m0s in right ascension and from −42° to −70° in declination. This region was observed on a nearly daily cadence from 2019 to 2022 and chosen to avoid the plane of the galaxy.
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Why Are (Almost) All the Protostellar Outflows Aligned in Serpens Main? Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Joel D. Green, Klaus M. Pontoppidan, Megan Reiter, Dan M. Watson, Sachindev S. Shenoy, P. Manoj, Mayank Narang
We present deep 1.4–4.8 μm JWST-NIRCam imaging of the Serpens Main star-forming region and identify 20 candidate protostellar outflows, most with bipolar structure and identified driving sources. The outflow position angles (PAs) are strongly correlated, and they are aligned within ±24° of the major axis of the Serpens filament. These orientations are further aligned with the angular momentum vectors
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Closing the Net on Transient Sources of Ultrahigh-energy Cosmic Rays Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Sullivan Marafico, Jonathan Biteau, Antonio Condorelli, Olivier Deligny, Johan Bregeon
The arrival directions of ultrahigh-energy cosmic rays (UHECRs) observed above 4 × 1019 eV provide evidence of localized excesses that are key to identifying their sources. We leverage the 3D matter distribution from optical and infrared surveys as a density model of UHECR sources, which are considered to be transient. Agreement of the sky model with UHECR data imposes constraints on both the emission
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A High-resolution Imaging Survey of Massive Young Stellar Objects in the Magellanic Clouds Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Venu M. Kalari, Ricardo Salinas, Hans Zinnecker, Monica Rubio, Gregory Herczeg, Morten Andersen
Constraints on the binary fraction of massive young stellar objects (mYSOs) are important for binary and massive star formation theory. Here, we present speckle imaging of 34 mYSOs located in the Large Magellanic Cloud (1/2 Z ⊙) and Small Magellanic Cloud (∼1/5 Z ⊙), probing projected separations in the 2000 to 20,000 au (at angular scales of 0.″02–0.″2) range, for stars above 8 M ⊙. We find two wide
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Time Profile Study of Type III Solar Radio Bursts Using Parker Solar Probe Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 Tulsi Thapa, Yihua Yan
Solar type III radio bursts are crucial indicators of energetic electron activity in the solar corona and interplanetary space. Our assessment of 43 interplanetary type III bursts, recorded by the FIELDS instrument on board the Parker Solar Probe during Encounters 05 to 11, has led to significant and complex findings. We have analyzed time profile features across a frequency range of 19–0.5 MHz, revealing
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Magnetization Factors of Gamma-Ray Burst Jets Revealed by a Systematic Analysis of the Fermi Sample Astrophys. J. (IF 4.8) Pub Date : 2024-08-21 An Li, He Gao, Lin Lan, Bing Zhang
The composition of gamma-ray burst (GRB) jets remained a mystery until recently. In practice, we usually characterize the magnetization of the GRB jets (σ 0) through the ratio between the Poynting flux and matter (baryonic) flux. With the increasing value of σ 0, magnetic energy gradually takes on a dominant role in the acceleration and energy dissipation of the jet, causing the proportion of thermal
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Robust r-process Nucleosynthesis beyond Lanthanides in the Common Envelop Jet Supernovae Astrophys. J. (IF 4.8) Pub Date : 2024-08-20 Shilun Jin, Noam Soker
The common envelop jet supernovae (CEJSNe) r-process scenario has been proposed as an r-process nucleosynthesis site in the past decade. Jets launched by a neutron star that spirals in inside the core of a red supergiant star in a common envelope evolution supply the proper conditions for forming elements heavier than iron through the rapid neutron-capture process. The present work initially unveils
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High-resolution Study of the Outflow Activity and Chemical Environment of Chamaeleon-MMS1 Astrophys. J. (IF 4.8) Pub Date : 2024-08-20 Veronica Allen, Martin A. Cordiner, Gilles Adande, Steven B. Charnley, Yi-Jehng Kuan, Eva Wirström
The earliest stages of low-mass star formation are unclear, with the first hydrostatic core (FHSC) as the transition stage between a prestellar and protostellar core. This work describes the local (∼4000 au) outflow activity associated with candidate FHSC Chamaeleon-MMS1 and its effect on the surrounding material to determine the evolutionary state of this young low-mass source. We observed Chamaeleon-MMS1
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Stellar Evolution in Real Time. II. R Hydrae and an Open-Source Grid of >3000 Seismic TP-AGB Models Computed with MESA Astrophys. J. (IF 4.8) Pub Date : 2024-08-20 Meridith Joyce, László Molnár, Giulia Cinquegrana, Amanda Karakas, Jamie Tayar, Dóra Tarczay-Nehéz
We present a comprehensive characterization of the evolved thermally pulsing asymptotic giant branch (TP-AGB) star R Hydrae (R Hya), building on the techniques applied in Stellar Evolution in Real Time I (Molnár et al.) to T Ursae Minoris. We compute over 3000 theoretical TP-AGB pulse spectra using MESA and the corresponding oscillation spectra with GYRE. We combine these with classical observational
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Ubiquitous Late Radio Emission from Tidal Disruption Events Astrophys. J. (IF 4.8) Pub Date : 2024-08-20 Y. Cendes, E. Berger, K. D. Alexander, R. Chornock, R. Margutti, B. Metzger, M. H. Wieringa, M. F. Bietenholz, A. Hajela, T. Laskar, M. C. Stroh, G. Terreran
We present radio observations of 23 optically discovered tidal disruption events (TDEs) on timescales of ∼500–3200 days postdiscovery. We detect nine new TDEs that did not have detectable radio emission at earlier times, indicating a late-time brightening after several hundred (and up to 2300) days; an additional seven TDEs exhibit radio emission whose origin is ambiguous or may be attributed to the