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How to Turn Jets into Cylinders near Supermassive Black Holes in 3D General Relativistic Magnetohydrodynamic Simulations Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-28 Valeriia Rohoza, Aretaios Lalakos, Max Paik, Koushik Chatterjee, Matthew Liska, Alexander Tchekhovskoy, Ore Gottlieb
Accreting supermassive black holes (SMBHs) produce highly magnetized relativistic jets that tend to collimate gradually as they propagate outward. However, recent radio interferometric observations of the 3C 84 galaxy reveal a stunning, cylindrical jet already at several hundred SMBH gravitational radii, r ≳ 350r g. We explore how such extreme collimation emerges via a suite of 3D general relativistic
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A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE): Impact of Galaxies on the Circumgalactic Medium Metal Enrichment at z > 6 Using the JWST and VLT Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-27 Siwei Zou, Zheng Cai, Feige Wang, Xiaohui Fan, Jaclyn B. Champagne, Joseph F. Hennawi, Jan-Torge Schindler, Emanuele Paolo Farina, Jinyi Yang, Kohei Inayoshi, Eduardo Bañados, Sarah E. I. Bosman, Zihao Li, Xiaojing Lin, Yunjing Wu, Fengwu Sun, Ziyi Guo, Girish Kulkuarni, Mélanie Habouzit, Stephane Charlot, Jacopo Chevallard, Thomas Connor, Anna-Christina Eilers, Linhua Jiang, Xiangyu Jin, Koki Kakiichi
We characterize the multiphase circumgalactic medium (CGM) and galaxy properties at z = 6.0–6.5 in four quasar fields from the James Webb Space Telescope A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE) program. We use the Very Large Telescope/X-shooter spectra of quasar J0305–3150 to identify one new metal absorber at z = 6.2713 with multiple transitions (O i, Mg ii, Fe ii,
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Optical Appearance of Eccentric Tidal Disruption Events Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-27 Fangyi (Fitz) Hu, Daniel J. Price, Ilya Mandel
Stars approaching supermassive black holes can be tidally disrupted. Despite being expected to emit X-rays, tidal disruption events (TDEs) have been largely observed in optical bands, which is poorly understood. In this Letter, we simulate the tidal disruption of a 1 M ⊙ main-sequence star on an eccentric (e = 0.95) orbit with a periapsis distance 1 or 5 times smaller than the tidal radius (β = 1 or
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The Very Early Soft X-Ray Plateau of GRB 230307A: Signature of an Evolving Radiative Efficiency in Magnetar Wind Dissipation? Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-27 Shu-Qing Zhong, Long Li, Di Xiao, Hui Sun, Bin-Bin Zhang, Zi-Gao Dai
Very recently, a particularly long gamma-ray burst (GRB) 230307A was reported and proposed to originate from a compact binary merger based on its host galaxy property, kilonova, and heavy elements. More intriguingly, a very early plateau followed by a rapid decline in the soft X-ray band was detected in its light curve by the Lobster Eye Imager for Astronomy, indicating strong evidence of the existence
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Lyman Continuum Leakers in the AstroSat Ultraviolet Deep Field: Extreme-ultraviolet Emitters at the Cosmic Noon Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-26 Suraj Dhiwar, Kanak Saha, Soumil Maulick, Brent M. Smith, Chayan Mondal, Harry I. Teplitz, Marc Rafelski, Rogier A. Windhorst
We report the direct detection of Lyman continuum (LyC) emission from nine galaxies and one active galactic nucleus at z ∼ 1.1–1.6 in the GOODS-North field using deep observations from the Ultraviolet Imaging Telescope (UVIT) on board AstroSat. The absolute escape fraction of the sources estimated from the far-ultraviolet and Hα-line luminosities using Monte Carlo analysis of two intergalactic medium
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Discovery of Magnetically Guided Metal Accretion onto a Polluted White Dwarf Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-26 Stefano Bagnulo, Jay Farihi, John D. Landstreet, Colin P. Folsom
Dynamically active planetary systems orbit a significant fraction of white dwarf stars. These stars often exhibit surface metals accreted from debris disks, which are detected through infrared excess or transiting structures. However, the full journey of a planetesimal from star-grazing orbit to final dissolution in the host star is poorly understood. Here, we report the discovery that the cool metal-polluted
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Classification of Enhanced Geoeffectiveness Resulting from High-speed Solar Wind Streams Compressing Slower Interplanetary Coronal Mass Ejections Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-26 Stephan G. Heinemann, Chaitanya Sishtla, Simon Good, Maxime Grandin, Jens Pomoell
High-speed solar wind streams (HSSs) interact with the preceding ambient solar wind to form stream interaction regions (SIRs), which are a primary source of recurrent geomagnetic storms. However, HSSs may also encounter and subsequently interact with interplanetary coronal mass ejections (ICMEs). In particular, the impact of the interaction between slower ICMEs and faster HSSs represents an unexplored
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Roaring to Softly Whispering: X-Ray Emission after ∼3.7 yr at the Location of the Transient AT2018cow and Implications for Accretion-powered Scenarios* * Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-26 Giulia Migliori, R. Margutti, B. D. Metzger, R. Chornock, C. Vignali, D. Brethauer, D. L. Coppejans, T. Maccarone, L. Rivera Sandoval, J. S. Bright, T. Laskar, D. Milisavljevic, E. Berger, A. J. Nayana
We present the first deep X-ray observations of luminous fast blue optical transient (LFBOT) AT 2018cow at ∼3.7 yr since discovery, together with the reanalysis of the observation at δ t ∼ 220 days. X-ray emission is significantly detected at a location consistent with AT 2018cow. The very soft X-ray spectrum and sustained luminosity are distinct from the spectral and temporal behavior of the LFBOT
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Advancing Solar Magnetic Field Extrapolations through Multiheight Magnetic Field Measurements Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-23 Robert Jarolim, Benoit Tremblay, Matthias Rempel, Momchil Molnar, Astrid M. Veronig, Julia K. Thalmann, Tatiana Podladchikova
Nonlinear force-free extrapolations are a common approach to estimate the 3D topology of coronal magnetic fields based on photospheric vector magnetograms. The force-free assumption is a valid approximation at coronal heights, but for the dense plasma conditions in the lower atmosphere, this assumption is not satisfied. In this study, we utilize multiheight magnetic field measurements in combination
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Role of Planetary Radius on Atmospheric Escape of Rocky Exoplanets Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-23 Laura Chin, Chuanfei Dong, Manasvi Lingam
Large-scale characterization of exoplanetary atmospheres is on the horizon, thereby making it possible in the future to extract their statistical properties. In this context, by using a well-validated model in the solar system, we carry out 3D magnetohydrodynamic simulations to compute nonthermal atmospheric ion escape rates of unmagnetized rocky exoplanets as a function of their radius based on fixed
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Restoration of the Tully–Fisher Relation by Statistical Rectification Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-23 Hai Fu
I employ the Lucy rectification algorithm to recover the inclination-corrected distribution of local disk galaxies in the plane of absolute magnitude (M i ) and H i velocity width (W 20). By considering the inclination angle as a random variable with a known probability distribution, the novel approach eliminates one major source of uncertainty in studies of the Tully–Fisher relation: inclination angle
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Can the Gravitational Wave Background Feel Wiggles in Spacetime? Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-22 Gen Ye, Alessandra Silvestri
Recently the international pulsar timing array collaboration has announced the first strong evidence for an isotropic gravitational-wave background (GWB). We propose that rapid small oscillations (wiggles) in the Hubble parameter would trigger a resonance with the propagating gravitational waves, leaving unique signatures in the GWB spectrum as sharp resonance peaks/troughs. The proposed signal can
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Collisional Shaping of Nuclear Star Cluster Density Profiles Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-22 Sanaea C. Rose, Morgan MacLeod
A supermassive black hole surrounded by a dense, nuclear star cluster resides at the center of many galaxies. In this dense environment, high-velocity collisions frequently occur between stars. About 10% of the stars within the Milky Way’s nuclear star cluster collide with other stars before evolving off the main sequence. Collisions preferentially affect tightly bound stars, which orbit most quickly
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Follow-up on the Supermassive Black Hole Binary Candidate J1048+7143: Successful Prediction of the Next Gamma-Ray Flare and Refined Binary Parameters in the Framework of the Jet Precession Model Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-22 Emma Kun, Ilja Jaroschewski, Julia Becker Tjus, Silke Britzen, Sándor Frey, Krisztina Éva Gabányi, Lang Cui, Xin Wang, Yuling Shen
Analyzing single-dish and very long baseline interferometry radio, as well as Fermi Large Area Telescope γ-ray observations, we explained the three major flares in the γ-ray light curve of FSRQ J1048+7143 with the spin–orbit precession of the dominant mass black hole in a supermassive black hole binary system. Here, we report on the detection of a fourth γ-ray flare from J1048+7143, appearing in the
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The Strength and Shapes of Contact Binary Objects Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-22 Alex J. Meyer, Daniel J. Scheeres
While contact binary objects are common in the solar system, their formation mechanism is unclear. In this work we examine several contact binaries and calculate the necessary strength parameters that allow the two lobes to merge without the smaller of the two being gravitationally destroyed by the larger. We find a small but nonzero amount of cohesion or a large friction angle is required for the
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The Jet and Resolved Features of the Central Supermassive Black Hole of M87 Observed with EHT in 2017—Comparison with the GMVA 86 GHz Results Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-22 Makoto Miyoshi, Yoshiaki Kato, Junichiro Makino, Masato Tsuboi
M87 is the best target for studying black hole accretion and jet formation. Reanalysis of the Event Horizon Telescope (EHT) public data at 230 GHz shows a core–knots structure at the center and jet features. We here compare this with the new results of GMVA at 86 GHz showing a spatially resolved central core. There are similarities and differences between the two. At 86 GHz, “two bright regions” are
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Progenitors of Low-redshift Gamma-Ray Bursts Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-21 Vahé Petrosian, Maria G. Dainotti
The bimodal distribution of the observed duration of gamma-ray bursts (GRBs) has led to the identification of two distinct progenitors; compact star mergers, comprising either two neutron stars (NSs) or an NS and a black hole, for short GRBs (SGRBs), and the so-called collapsars for long GRBs (LGRBs). It is therefore expected that formation rate (FR) of LGRBs should be similar to the cosmic star formation
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Magnetar as the Central Engine of AT2018cow: Optical, Soft X-Ray, and Hard X-Ray Emission Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-21 Long Li, Shu-Qing Zhong, Di Xiao, Zi-Gao Dai, Shi-Feng Huang, Zhen-Feng Sheng
AT2018cow is the most extensively observed and widely studied fast blue optical transient to date; its unique observational properties challenge all existing standard models. In this paper, we model the luminosity evolution of the optical, soft X-ray, and hard X-ray emission, as well as the X-ray spectrum of AT2018cow with a magnetar-centered engine model. We consider a two-zone model with a striped
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On the Scarcity of Dense Cores (n > 105 cm−3) in High-latitude Planck Galactic Cold Clumps Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-21 Fengwei Xu, Ke Wang, Tie Liu, David Eden, Xunchuan Liu, Mika Juvela, Jinhua He, Doug Johnstone, Paul Goldsmith, Guido Garay, Yuefang Wu, Archana Soam, Alessio Traficante, Isabelle Ristorcelli, Edith Falgarone, Huei-Ru Vivien Chen, Naomi Hirano, Yasuo Doi, Woojin Kwon, Glenn J. White, Anthony Whitworth, Patricio Sanhueza, Mark G. Rawlings, Dana Alina, Zhiyuan Ren, Chang Won Lee, Ken’ichi Tatematsu,
High-latitude (∣b∣ > 30°) molecular clouds have virial parameters that exceed 1, but whether these clouds can form stars has not been studied systematically. Using JCMT SCUBA-2 archival data, we surveyed 70 fields that target high-latitude Planck Galactic cold clumps (HLPCs) to find dense cores with density of 105–106 cm−3 and size of <0.1 pc. The sample benefits from both the representativeness of
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A Comptonized Fireball Bubble Fits the Second Extragalactic Magnetar Giant Flare GRB 231115A Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-21 Yi-Han Iris Yin, Zhao Joseph Zhang, Jun Yang, Run-Chao Chen, Umer Rehman, Varun Bahal, Bin-Bin Zhang
Magnetar giant flares (MGFs), originating from noncatastrophic magnetars, share noteworthy similarities with some short gamma-ray bursts (GRBs). However, understanding their detailed origin and radiation mechanisms remains challenging due to limited observations. The discovery of MGF GRB 231115A, the second extragalactic MGF located in the Cigar galaxy at a luminosity distance of ∼3.5 Mpc, offers yet
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Intermittent Electron-only Reconnection at Lunar Mini-magnetospheres Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-21 A. Stanier, L. J. Chen, A. Le, J. Halekas, R. Sawyer
Lunar crustal magnetic anomalies (LCMA) are sub-ion-gyroradius structures that have been shown to stand off the solar wind (SW) plasma from the Moon’s surface, forming shock-like discontinuities and reflecting incident SW protons. In this Letter, the results of high-resolution, 2D fully kinetic simulations show a bursty electron-only magnetic reconnection in the SW-LCMA interaction region, characterized
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JWST Observations of K2-18b Can Be Explained by a Gas-rich Mini-Neptune with No Habitable Surface Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-20 Nicholas F. Wogan, Natasha E. Batalha, Kevin J. Zahnle, Joshua Krissansen-Totton, Shang-Min Tsai, Renyu Hu
The James Webb Space Telescope (JWST) recently measured the transmission spectrum of K2-18b, a habitable-zone sub-Neptune exoplanet, detecting CH4 and CO2 in its atmosphere. The discovery paper argued the data are best explained by a habitable “Hycean” world, consisting of a relatively thin H2-dominated atmosphere overlying a liquid water ocean. Here, we use photochemical and climate models to simulate
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JWST Transmission Spectroscopy of HD 209458b: A Supersolar Metallicity, a Very Low C/O, and No Evidence of CH4, HCN, or C2H2 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-20 Qiao Xue, Jacob L. Bean, Michael Zhang, Luis Welbanks, Jonathan Lunine, Prune August
We present the transmission spectrum of the original transiting hot Jupiter HD 209458b from 2.3 to 5.1 μm as observed with the NIRCam instrument on the James Webb Space Telescope (JWST). Previous studies of HD 209458b’s atmosphere have given conflicting results on the abundance of H2O and the presence of carbon- and nitrogen-bearing species, which have significant ramifications on the inferences of
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Energy Deposition into the Ionosphere during a Solar Flare with Extreme-ultraviolet Late Phase Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-20 Jing Liu, Liying Qian, Wenbin Wang, Kevin Pham, Xiangliang Kong, Yao Chen, Wenlong Liu, Libo Liu, Xuanqing Liu
Solar extreme-ultraviolet (EUV) irradiance is the dominant energy source for ionizing and heating the Earth’s upper atmosphere. It is common to assume that the spectra of different EUV lines have the same trend to fill the solar EUV irradiance gap for modeling purposes due to inadequate EUV irradiance measurements. However, the spectra across the EUV bands may not vary in the same trend. The flare
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Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-20 W. S. Kurth
The two Voyager spacecraft have been exploring the interstellar medium beyond the heliopause since 2012 (Voyager 1) and 2018 (Voyager 2). Electron plasma oscillations and a quasi-thermal noise line at the electron plasma frequency have enabled the determination of the electron density in this region, revealing a radial density gradient convolved with shocks and pressure fronts. Voyager 1 has a functioning
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Chandra’s Insights into SN 2023ixf Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-20 Poonam Chandra, Roger A. Chevalier, Keiichi Maeda, Alak K. Ray, Nayana A. J.
We report Chandra-ACIS observations of supernova (SN) 2023ixf in M101 on day 13 and 86 since the explosion. The X-rays in both epochs are characterized by high-temperature plasma from the forward shocked region as a result of circumstellar interaction. We are able to constrain the absorption column density at both Chandra epochs, which is much larger than that due to the Galactic and host absorption
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The White-light Emissions in Two X-class Flares Observed by ASO-S and CHASE Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-20 Ying Li, Zhichen Jing, De-Chao Song, Qiao Li, Jun Tian, Xiaofeng Liu, Ya Wang, M. D. Ding, Andrea Francesco Battaglia, Li Feng, Hui Li, Weiqun Gan
The white-light continuum emissions in solar flares (i.e., white-light flares) are usually observed on the solar disk but, in a few cases, off the limb. Here we present on-disk as well as off-limb continuum emissions at 3600 Å (in the Balmer continuum) in an X2.1 flare (SOL2023-03-03T17:52) and an X1.5 flare (SOL2023-08-07T20:46), respectively, observed by the White-light Solar Telescope on the Advanced
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The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. IV. NIRISS Aperture Masking Interferometry Performance and Lessons Learned Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-19 Steph Sallum, Shrishmoy Ray, Jens Kammerer, Anand Sivaramakrishnan, Rachel Cooper, Alexandra Z. Greebaum, Deepashri Thatte, Matthew De Furio, Samuel M. Factor, Michael R. Meyer, Jordan M. Stone, Aarynn Carter, Beth Biller, Sasha Hinkley, Andrew Skemer, Genaro Suárez, Jarron M. Leisenring, Marshall D. Perrin, Adam L. Kraus, Olivier Absil, William O. Balmer, Sarah K. Betti, Anthony Boccaletti, Mariangela
We present a performance analysis for the aperture masking interferometry (AMI) mode on board the James Webb Space Telescope Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS). Thanks to self-calibrating observables, AMI accesses inner working angles down to and even within the classical diffraction limit. The scientific potential of this mode has recently been demonstrated by the Early Release
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Ultraviolet Quasiperiodic Eruptions from Star–Disk Collisions in Galactic Nuclei Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-19 Itai Linial, Brian D. Metzger
“Quasiperiodic eruptions” (QPE) are recurrent nuclear transients with periods of several hours to almost a day, which thus far have been detected exclusively in the X-ray band. We have shown that many of the key properties of QPE flares (period, luminosity, duration, emission temperature, alternating long-short recurrence time behavior, and source rates) are naturally reproduced by a scenario involving
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Investigation of a Magnetic Reconnection Event with Extraordinarily High Particle Energization in Magnetotail Turbulence Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-16 Yi Qi, Robert Ergun, Neha Pathak, Tai D. Phan, James L. Burch, Alexandros Chasapis, Tak Chu Li, Steven J. Schwartz, Narges Ahmadi, Tien Vo, Stefan Eriksson, David Newman, Maria Usanova, Frederick D. Wilder
Magnetic reconnection and plasma turbulence are ubiquitous and key processes in the Universe. These two processes are suggested to be intrinsically related: magnetic reconnection can develop turbulence, and, in turn, turbulence can influence or excite magnetic reconnection. In this study, we report a rare and unique electron diffusion region (EDR) observed by the Magnetospheric Multiscale mission in
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The First Robust Evidence Showing a Dark Matter Density Spike Around the Supermassive Black Hole in OJ 287 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-16 Man Ho Chan, Chak Man Lee
Black hole dynamics suggests that dark matter would redistribute near a supermassive black hole (SMBH) to form a density spike. However, no direct evidence of a dark matter density spike around an SMBH has been identified. In this Letter, we present the first robust evidence showing a dark matter density spike around an SMBH. We revisit the data of the well-known SMBH binary OJ 287 and show that the
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Evidence for a Compact Stellar Merger Origin for GRB 230307A From Fermi-LAT and Multiwavelength Afterglow Observations Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-16 Cui-Yuan Dai, Chen-Lei Guo, Hai-Ming Zhang, Ruo-Yu Liu, Xiang-Yu Wang
GRB 230307A is the second-brightest gamma-ray burst (GRB) ever detected over 50 yr of observations and has a long duration in the prompt emission. Two galaxies are found to be close to the position of GRB 230307A: (1) a distant (z ∼ 3.87) star-forming galaxy, located at an offset of ∼0.″2–0.″3 from the GRB position (with a projected distance of ∼1–2 kpc); (2) a nearby (z = 0.065) spiral galaxy, located
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Is Betelgeuse Really Rotating? Synthetic ALMA Observations of Large-scale Convection in 3D Simulations of Red Supergiants Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-16 Jing-Ze Ma, Andrea Chiavassa, Selma E. de Mink, Ruggero Valli, Stephen Justham, Bernd Freytag
The evolved stages of massive stars are poorly understood, but invaluable constraints can be derived from spatially resolved observations of nearby red supergiants, such as Betelgeuse. Atacama Large Millimeter/submillimeter Array (ALMA) observations of Betelgeuse showing a dipolar velocity field have been interpreted as evidence for a projected rotation rate of about 5 km s−1. This is 2 orders of magnitude
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Formation of Fan-spine Magnetic Topology through Flux Emergence and Subsequent Jet Production Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-16 Yadan Duan, Hui Tian, Hechao Chen, Yuandeng Shen, Zheng Sun, Zhenyong Hou, Chuan Li
Fan-spine magnetic structure, as a fundamental three-dimensional topology in magnetic reconnection theory, plays a crucial role in producing solar jets. However, how fan-spine configurations form in the solar atmosphere remains elusive. Using the Chinese Hα Solar Explorer (CHASE) and the Solar Dynamics Observatory, we present a case study on the complete buildup of fan-spine topology driven by flux
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Classifying Optical (Out)bursts in Cataclysmic Variables: The Distinct Observational Characteristics of Dwarf Novae, Micronovae, Stellar Flares, and Magnetic Gating Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-15 Krystian Iłkiewicz, Simone Scaringi, Martina Veresvarska, Domitilla De Martino, Colin Littlefield, Christian Knigge, John A. Paice, Anwesha Sahu
Cataclysmic variables can experience short optical brightenings, which are commonly attributed to phenomena such as dwarf novae outbursts, micronovae, donor flares, or magnetic gating bursts. Since these events exhibit similar observational characteristics, their identification has often been ambiguous. In particular, magnetic gating bursts and micronovae have been suggested as alternative interpretations
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Calcium Bright Knots and the Formation of Chromospheric Anemone Jets on the Sun Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-15 Kunwar Alkendra Pratap Singh, Keisuke Nishida, Kazunari Shibata
Space-based observations show that the solar atmosphere from the solar chromosphere to the solar corona is filled with small-scale jets and is linked with small-scale explosions. These jets may be produced by mechanisms similar to those of large-scale flares and such jets may be related to the heating of the corona and chromosphere as well as the acceleration of solar wind. The chromospheric anemone
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JWST Directly Images Giant Planet Candidates Around Two Metal-polluted White Dwarf Stars Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-15 Susan E. Mullally, John Debes, Misty Cracraft, Fergal Mullally, Sabrina Poulsen, Loic Albert, Katherine Thibault, William T. Reach, J. J. Hermes, Thomas Barclay, Mukremin Kilic, Elisa V. Quintana
We report the discovery of two directly imaged, giant planet candidates orbiting the metal-rich, hydrogen atmosphere white dwarfs WD 1202−232 and WD 2105−82. JWST’s Mid-Infrared Instrument (MIRI) data on these two stars show a nearby resolved source at a projected separation of 11.47 and 34.62 au, respectively. Assuming the planets formed at the same time as their host stars, with total ages of 5.3
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Primordial Orbital Alignment of Sednoids Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-15 Yukun Huang, Brett Gladman
We examined the past history of the three most detached trans-Neptunian objects (TNOs)—Sedna, 2012 VP113, and Leleakuhonua (2015 TG387)—the three clearest members of the dynamical class known as sednoids, with high perihelia distances q. By integrating backward their nominal (and a set of cloned) orbits for the solar system’s age, we surprisingly find that the only time all their apsidal lines tightly
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Detection of Metal Enrichment by SN 2011jm in NGC 4809 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-14 Yulong Gao, Qiusheng Gu, Ping Zhou, Yong Shi, Xiangdong Li
Cosmic metals are believed to originate from stellar and supernovae (SNe) nucleosynthesis, dispersed into the interstellar medium (ISM) through stellar winds and supernova explosions. In this paper, we present the clear evidence of metal enrichment by a Type Ic SN 2011jm in the galaxy NGC 4809, utilizing high spatial resolution integral field unit observations obtained from the Very Large Telescope/Multi
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Turbulently Driven Detonation Initiation in Electron-degenerate Matter with Helium Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-14 Gabriel O. Casabona, Robert T. Fisher
Type Ia supernovae (SNe Ia) are standardizable cosmological candles that led to the discovery of the accelerating Universe. However, the physics of how white dwarfs (WDs) explode and lead to SNe Ia is still poorly understood. The initiation of the detonation front that rapidly disrupts the WD is a crucial element of the puzzle, and global 3D simulations of SNe Ia cannot resolve the requisite length
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Measuring Tracers of Planet Formation in the Atmosphere of WASP-77A b: Substellar O/H and C/H Ratios, with a Stellar C/O Ratio and a Potentially Superstellar Ti/H Ratio Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-14 Billy Edwards, Quentin Changeat
We present a comprehensive atmospheric retrieval study of the hot Jupiter WASP-77A b using eclipse observations from the Hubble Space Telescope (HST) and JWST. Using atmospheric retrievals, the spectral features of H2O, CO, and TiO are identified, with volume mixing ratios estimated at log10(VMR) = −4.40 −0.11+0.14 , −4.44 −0.28+0.34 , and −6.40 −0.23+0.22 , respectively. We derive the atmospheric
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Surface Charging of Jupiter’s Moon Europa Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-14 Sachin A. Reddy, Tom A. Nordheim, Camilla D. K. Harris
Europa’s surface is exposed to a constant flow of plasma from its ionosphere and Jupiter’s magnetosphere. As these particles flow onto the surface, an electrostatic surface potential forms. We investigate the electrostatic charging of Europa’s surface using 3D particle-in-cell simulations. We find that surface potentials on Europa vary from −14 to −52 V. The predicted surface potentials vary as a function
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Passing Stars as an Important Driver of Paleoclimate and the Solar System’s Orbital Evolution Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-14 Nathan A. Kaib, Sean N. Raymond
Reconstructions of the paleoclimate indicate that ancient climatic fluctuations on Earth are often correlated with variations in its orbital elements. However, the chaos inherent in the solar system’s orbital evolution prevents numerical simulations from confidently predicting Earth’s past orbital evolution beyond 50–100 Myr. Gravitational interactions among the Sun’s planets and asteroids are believed
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The Progenitor and Central Engine of a Peculiar GRB 230307A Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-14 ZhaoWei Du, HouJun Lü, Yong Yuan, Xing Yang, EnWei Liang
Recently, a lack of supernova-associated with long-duration gamma-ray burst (GRB 230307A) at such a low redshift z = 0.065, but associated with a possible kilonova emission, has attracted great attention. Its heavy element nucleosynthesis and the characteristic of soft X-ray emission suggest that the central engine of GRB 230307A is a magnetar that is originated from a binary compact star merger. The
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True Pair-instability Supernova Descendant: Implications for the First Stars’ Mass Distribution Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-13 Ioanna Koutsouridou, Stefania Salvadori, Ása Skúladóttir
The initial mass function (IMF) of the first Population III (Pop III) stars remains a persistent mystery. Their predicted massive nature implies the existence of stars exploding as pair-instability supernovae (PISNe), but no observational evidence had been found. Now, the LAMOST survey claims to have discovered a pure PISN descendant, J1010+2358, at [Fe/H] = − 2.4. Here we confirm that a massive 250–260
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Did a Kilonova Set Off in Our Galactic Backyard 3.5 Myr ago? Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-13 Leonardo Chiesa, Albino Perego, Federico Maria Guercilena
The recent detection of the live isotopes 60Fe and 244Pu in deep ocean sediments dating back to the past 3–4 Myr poses a serious challenge to the identification of their production site(s). While 60Fe is usually attributed to standard core-collapse supernovae, actinides are r-process nucleosynthesis yields, which are believed to be synthesized in rare events, such as special classes of supernovae or
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Improved Upper Limits on Gravitational-wave Emission from NS 1987A in SNR 1987A Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-13 Benjamin J. Owen, Lee Lindblom, Luciano Soares Pinheiro, Binod Rajbhandari
We report on a new search for continuous gravitational waves from NS 1987A, the neutron star born in SN 1987A, using open data from Advanced LIGO and Virgo’s third observing run (O3). The search covered frequencies from 35–1050 Hz, more than 5 times the band of the only previous gravitational-wave search to constrain NS 1987A. Our search used an improved code and coherently integrated from 5.10 to
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TOI-4201: An Early M Dwarf Hosting a Massive Transiting Jupiter Stretching Theories of Core Accretion* * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-13 Megan Delamer, Shubham Kanodia, Caleb I. Cañas, Simon Müller, Ravit Helled, Andrea S. J. Lin, Jessica E. Libby-Roberts, Arvind F. Gupta, Suvrath Mahadevan, Johanna Teske, R. Paul Butler, Samuel W. Yee, Jeffrey D. Crane, Stephen Shectman, David Osip, Yuri Beletsky, Andrew Monson, Leslie Hebb, Luke C. Powers, John P. Wisniewski, Jaime A. Alvarado-Montes, Chad F. Bender, Jiayin Dong, Te Han, Joe P. Ninan
We confirm TOI-4201 b as a transiting Jovian-mass planet orbiting an early M dwarf discovered by the Transiting Exoplanet Survey Satellite. Using ground-based photometry and precise radial velocities from NEID and the Planet Finder Spectrograph, we measure a planet mass of 2.59−0.06+0.07 M J, making this one of the most massive planets transiting an M dwarf. The planet is ∼0.4% of the mass of its 0
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Eccentricity Distribution beyond the Snow Line and Implications for Planetary Habitability Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-09 Stephen R. Kane, Robert A. Wittenmyer
A fundamental question in the study of planetary system demographics is: how common is the solar system architecture? The primary importance of this question lies in the potential of planetary systems to create habitable environments, and dissecting the various components of solar system evolution that contributed to a sustainable temperate surface for Earth. One important factor in that respect is
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Muted Features in the JWST NIRISS Transmission Spectrum of Hot Neptune LTT 9779b Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-08 Michael Radica, Louis-Philippe Coulombe, Jake Taylor, Loic Albert, Romain Allart, Björn Benneke, Nicolas B. Cowan, Lisa Dang, David Lafrenière, Daniel Thorngren, Étienne Artigau, René Doyon, Laura Flagg, Doug Johnstone, Stefan Pelletier, Pierre-Alexis Roy
The hot Neptune desert is one of the most sparsely populated regions of the exoplanet parameter space, and atmosphere observations of its few residents can provide insights into how such planets have managed to survive in such an inhospitable environment. Here, we present transmission observations of LTT 9779 b, the only known hot Neptune to have retained a significant H/He-dominated atmosphere, taken
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A High-resolution Non-detection of Escaping Helium in the Ultrahot Neptune LTT 9779b: Evidence for Weakened Evaporation Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-08 Shreyas Vissapragada, Patrick McCreery, Leonardo A. Dos Santos, Néstor Espinoza, Andrew McWilliam, Noriyuki Matsunaga, Jéa Adams Redai, Patrick Behr, Kevin France, Satoshi Hamano, Charlie Hull, Yuji Ikeda, Haruki Katoh, Hideyo Kawakita, Mercedes López-Morales, Kevin N. Ortiz Ceballos, Shogo Otsubo, Yuki Sarugaku, Tomomi Takeuchi
The recent discovery of “ultrahot” (P < 1 day) Neptunes has come as a surprise: some of these planets have managed to retain gaseous envelopes despite being close enough to their host stars to trigger strong photoevaporation and/or Roche lobe overflow. Here, we investigate atmospheric escape in LTT 9779b, an ultrahot Neptune with a volatile-rich envelope. We observed two transits of this planet using
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JWST Observations Reject Unrecognized Crowding of Cepheid Photometry as an Explanation for the Hubble Tension at 8σ Confidence Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 Adam G. Riess, Gagandeep S. Anand, Wenlong Yuan, Stefano Casertano, Andrew Dolphin, Lucas M. Macri, Louise Breuval, Dan Scolnic, Marshall Perrin, Richard I. Anderson
We present high-definition observations with the James Webb Space Telescope (JWST) of >1000 Cepheids in a geometric anchor of the distance ladder, NGC 4258, and in five hosts of eight Type Ia supernovae, a far greater sample than previous studies with JWST. These galaxies individually contain the largest samples of Cepheids, an average of >150 each, producing the strongest statistical comparison to
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Changing-look Active Galactic Nuclei Behavior Induced by Disk-captured Tidal Disruption Events Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 Yihan Wang, Douglas N. C. Lin, Bing Zhang, Zhaohuan Zhu
Recent observations of changing-look active galactic nuclei (AGNs) hint at a frequency of accretion activity not fully explained by tidal disruption events (TDEs) stemming from relaxation processes in nuclear star clusters (NSCs), traditionally estimated to occur at rates of 10−4–10−5 yr−1 per galaxy. In this Letter, we propose an enhanced TDE rate through the AGN disk capture process, presenting a
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Predicting the Timing of the Solar Cycle 25 Polar Field Reversal Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 Bibhuti Kumar Jha, Lisa A. Upton
The process of the Sun’s polar field cancellation reversal commences with the emergence of new cycle Hale’s polarity active regions. Once the Sun undergoes polarity reversal, typically occurring near the peak of solar activity, it begins the process of accumulating the seed field for the forthcoming solar cycle. In recent years, the advective flux transport (AFT) model has proven highly effective in
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Rapid Chemical Enrichment by Intermittent Star Formation in GN-z11 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 Chiaki Kobayashi, Andrea Ferrara
We interpret the peculiar supersolar nitrogen abundance recently reported by the James Webb Space Telescope observations for GN-z11 (z = 10.6) using our state-of-the-art chemical evolution models. The observed CNO ratios can be successfully reproduced—independently of the adopted initial mass function, nucleosynthesis yields, and presence of supermassive (>1000M ⊙) stars—if the galaxy has undergone
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Discovery of a Collimated Jet from the Low-luminosity Protostar IRAS 16253−2429 in a Quiescent Accretion Phase with the JWST Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 Mayank Narang, P. Manoj, Himanshu Tyagi, Dan M. Watson, S. Thomas Megeath, Samuel Federman, Adam E. Rubinstein, Robert Gutermuth, Alessio Caratti o Garatti, Henrik Beuther, Tyler L. Bourke, Ewine F. Van Dishoeck, Neal J. Evans, Guillem Anglada, Mayra Osorio, Thomas Stanke, James Muzerolle, Leslie W. Looney, Yao-Lun Yang, Pamela Klaassen, Nicole Karnath, Prabhani Atnagulov, Nashanty Brunken, William
Investigating Protostellar Accretion (IPA) is a JWST Cycle 1 GO program that uses NIRSpec integral field units and MIRI Medium Resolution Spectrograph to obtain 2.9–28 μm spectral cubes of young, deeply embedded protostars with luminosities of 0.2–10,000 L ⊙ and central masses of 0.15–12 M ⊙. In this Letter, we report the discovery of a highly collimated atomic jet from the Class 0 protostar IRAS 16253−2429
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Delayed and Fast-rising Radio Flares from an Optical and X-Ray-detected Tidal Disruption Event in the Center of a Dwarf Galaxy Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 Fabao Zhang, Xinwen Shu, Lei Yang, Luming Sun, Zhumao Zhang, Yibo Wang, Guobin Mou, Xue-Guang Zhang, Tianyao Zhou, Fangkun Peng
AT 2018cqh is a unique tidal disruption event (TDE) discovered in a dwarf galaxy. Both the light-curve fitting and galaxy scaling relationships suggest a central black hole mass in the range of 5.9 < logM BH/M ☉ < 6.4. The r-band peak luminosity is ∼ 1043 erg s−1, making AT 2018cqh relatively faint among known optical TDEs. A delayed X-ray brightening was found around 590 days after the optical discovery
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Tracing the Origins of Mass Segregation in M35: Evidence for Primordially Segregated Binaries Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 Erin Motherway, Aaron M. Geller, Anna C. Childs, Claire Zwicker, Ted von Hippel
M35 is a young open cluster and home to an extensive binary population. Using Gaia Data Release 3, Pan-STARRS, and Two Micron All Sky Survey photometry with the Bayesian statistical software, BASE-9, we derive precise cluster parameters, identify single and binary cluster members, and extract their masses. We identify 571 binaries down to Gaia G = 20.3 and a lower limit on the binary frequency of f
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SMA Detection of an Extreme Millimeter Flare from the Young Class III Star HD 283572 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 Joshua Bennett Lovell, Garrett K. Keating, David J. Wilner, Sean M. Andrews, Meredith MacGregor, Ramisa Akther Rahman, Ramprasad Rao, Jonathan P. Williams
We present evidence of variable 1.3 mm emission from the 1 to 3 Myr, spectral-type G2–G5 class III young stellar object (YSO), HD 283572. HD 283572 was observed on eight dates with the Submillimeter Array between 2021 December and 2023 May, with a total on-source time of 10.2 hr, probing a range of timescales down to 5.2 s. Averaging all data obtained on 2022 January 17 shows a 4.4 mJy (8.8σ) point
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Effects of Nonzero-frequency Fluctuations on Turbulence Spectral Observations Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-02-06 L.-L. Zhao, G. P. Zank, H. Li
In situ observations of turbulence spectra in space plasmas are usually interpreted as wavenumber spectra, assuming that the fluctuation frequency is negligible in the plasma flow frame. We explore the effects of nonzero frequency in the plasma flow frame on turbulence spectral observations. The finite frequency can be caused by either propagating waves or nonlinear broadening of nonpropagating structures