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The Cause of the Difference in the Propagation Distances between Compact and Transient Jets in Black Hole X-Ray Binaries Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-14 Andrzej A. Zdziarski and Sebastian Heinz
Accreting black hole binaries change their properties during evolution, passing through two main luminous states, dominated by either hard or soft X-rays. In the hard state, steady compact jets emitting multiwavelength radiation are present. Those jets are usually observed in radio, and when resolved, their extent is ≲1015 cm. Then, during hard-to-soft transitions, powerful ejecta in the form of blobs
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High-resolution Pan-STARRS and SMA Observations of IRAS 23077+6707: A Giant Edge-on Protoplanetary Disk Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-12 Kristina Monsch, Joshua Bennett Lovell, Ciprian T. Berghea, Gordian Edenhofer, Garrett K. Keating, Sean M. Andrews, Ammar Bayyari, Jeremy J. Drake and David J. Wilner
We present resolved images of IRAS 23077+6707 (“Dracula’s Chivito”) in 1.3 mm/225 GHz thermal dust and CO gas emission with the Submillimeter Array (SMA) and optical (0.5–0.8 μm) scattered light with the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). The Pan-STARRS data show a bipolar distribution of optically scattering dust that is characteristic for disks observed at high inclinations
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Jupiter Co-Orbital Comet P/2023 V6 (PANSTARRS): Orbital History and Modern Activity State Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-12 Theodore Kareta, John W. Noonan, Kathryn Volk, Ryder H. Strauss and David Trilling
The discovery of the transient Jupiter co-orbital comet P/2019 LD2 (ATLAS) drew significant interest. Not only will LD2 transition between being a Centaur and a Jupiter-family comet (JFC) in 2063, the first time this process can be observed as it happens, it is also very active for its large heliocentric distance. We present observations and orbital integrations of the newly discovered transient Jupiter
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The Dependence of Gamma-Ray Burst Jet Collimation on Black Hole Spin Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-12 Valeria U. Hurtado, Nicole M. Lloyd-Ronning and Jonah M. Miller
Gamma-ray bursts (GRBs) are the most luminous events in the Universe and are excellent laboratories to study extreme physical phenomena in the cosmos. Despite a long trajectory of progress in understanding these highly energetic events, there are still many observed features that are yet to be fully explained. Observations of the jet opening angle of long gamma-ray bursts (LGRBs) suggest that LGRB
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Improving Photometric Redshift Estimates with Training Sample Augmentation Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-12 Irene Moskowitz, Eric Gawiser, John Franklin Crenshaw, Brett H. Andrews, Alex I. Malz, Samuel Schmidt and The LSST Dark Energy Science Collaboration
Large imaging surveys will rely on photometric redshifts (photo-z's), which are typically estimated through machine-learning methods. Currently planned spectroscopic surveys will not be deep enough to produce a representative training sample for Legacy Survey of Space and Time (LSST), so we seek methods to improve the photo-z estimates that arise from nonrepresentative training samples. Spectroscopic
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Dracula’s Chivito: Discovery of a Large Edge-on Protoplanetary Disk with Pan-STARRS Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-12 Ciprian T. Berghea, Ammar Bayyari, Michael L. Sitko, Jeremy J. Drake, Ana Mosquera, Cecilia Garraffo, Thomas Petit, Ray W. Russell and Korash D. Assani
We report the serendipitous discovery of a large edge-on protoplanetary disk in Pan-STARRS (PS1) images. PS1 has five broadband filters designated as gP1, rP1, iP1, zP1, and yP1 with mean wavelengths 4866, 6215, 7545, 8679, and 9633 Å, respectively. The disk’s apparent size in the PS1 images is ≈11″, making this one of the largest known disks on the sky. It is likely a young system, still surrounded
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Phosphorus Enrichment by ONe Novae in the Galaxy Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-10 Kenji Bekki, Takuji Tsujimoto
Recent observations have shown that [P/Fe] in the Galactic stars decreases with increasing [Fe/H] for [Fe/H] ≳ − 1 whereas it is almost subsolar for [Fe/H] ≲ −2. These [P/Fe] trends with [Fe/H] have not been well reproduced by previous theoretical models incorporating phosphorus (P) enrichment only by core collapse supernoave. We here show, for the first time, that the trends can be naturally explained
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The Hi Mass Function of Star-forming Galaxies at z ≈ 1 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-09 Aditya Chowdhury, Nissim Kanekar, Jayaram N. Chengalur
We present the first estimate, based on direct Hi 21 cm observations, of the Hi mass function (HiMF) of star-forming galaxies at z ≈ 1, obtained by combining our measurement of the scaling relation between Hi mass (M Hi ) and B-band luminosity (M B ) of star-forming galaxies with a literature estimate of the B-band luminosity function at z ≈ 1. We determined the M Hi –M B relation by using the GMRT-CATz1
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X-Rays from a Central “Exhaust Vent” of the Galactic Center Chimney Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-09 Scott C. Mackey, Mark R. Morris, Gabriele Ponti, Konstantina Anastasopoulou, Samaresh Mondal
Using deep archival observations from the Chandra X-ray Observatory, we present an analysis of linear X-ray-emitting features located within the southern portion of the Galactic center chimney and oriented orthogonal to the Galactic plane, centered at coordinates l = 0.°08, b = −1.°42. The surface brightness and hardness ratio patterns are suggestive of a cylindrical morphology, which may have been
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Expected Impact of Glints from Space Debris in the LSST Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-09 J. Anthony Tyson, Adam Snyder, Daniel Polin, Meredith L. Rawls, Željko Ivezić
We examine the simple model put forth in a recent note by Loeb regarding the brightness of space debris in the size range of 1–10 cm and their impact on the Rubin Observatory Legacy Survey of Space and Time (LSST) transient object searches. Their main conclusion was that “image contamination by untracked space debris might pose a bigger challenge [than large commercial satellite constellations in Low-Earth
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The Most Distant H i Galaxies Discovered by the 500 m Dish FAST Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-09 Hongwei Xi, Bo Peng, Lister Staveley-Smith, Bi-Qing For, Bin Liu, Ru-Rong Chen, Lei Yu, Dejian Ding, Wei-Jian Guo, Hu Zou, Suijian Xue, Jing Wang, Thomas G. Brink, WeiKang Zheng, Alexei V. Filippenko, Yi Yang, Jianyan Wei, Y. Sophia Dai, Zi-Jian Li, Zizhao He, Chengzi Jiang, Alexei Moiseev, Sergey Kotov
Neutral hydrogen (H i) is the primary component of the cool interstellar medium (ISM) and is the reservoir of fuel for star formation. Owing to the sensitivity of existing radio telescopes, our understanding of the evolution of the ISM in galaxies remains limited, as it is based on only a few hundred galaxies detected in H i beyond the local Universe. With the high sensitivity of the Five-hundred-meter
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Possibility of Secondary i- and s-processes Following r-process in the Collapsar Jet Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-09 Zhenyu He, Toshitaka Kajino, Motohiko Kusakabe, Shan-Gui Zhou, Hiroyuki Koura, Satoshi Chiba, Haining Li, Yangming Lin
The slow and intermediate neutron-capture processes, s- and i-processes, are believed to occur in asymptotic giant branch stars to provide half of the heavy atomic nuclei with A ≥ 90. We suggest a possibility that certain types of outflows found in the collapsar, which is a supernova generated by a rapidly rotating massive star undergoing core collapse, leaving behind a black hole and emitting relativistic
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Detecting Population III Stars through Tidal Disruption Events in the Era of JWST and Roman Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-08 Rudrani Kar Chowdhury, Janet N. Y. Chang, Lixin Dai, Priyamvada Natarajan
The first-generation metal-free stars, referred to as Population III (Pop III) stars, are believed to be the first objects to form out of the pristine gas in the very early Universe. Pop III stars have different structures from the current generation of stars and are important for generating heavy elements and shaping subsequent star formation. However, it is very challenging to directly detect Pop
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Dramatic Drop in the X-Ray Polarization of Swift J1727.8–1613 in the Soft Spectral State Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-07 Jiří Svoboda, Michal Dovčiak, James F. Steiner, Philip Kaaret, Jakub Podgorný, Juri Poutanen, Alexandra Veledina, Fabio Muleri, Roberto Taverna, Henric Krawczynski, Maïmouna Brigitte, Sudeb Ranjan Datta, Stefano Bianchi, Teo Muñoz-Darias, Michela Negro, Nicole Rodriguez Cavero, Noel Castro Segura, Niek Bollemeijer, Javier A. García, Adam Ingram, Giorgio Matt, Edward Nathan, Martin C. Weisskopf, Diego
Black hole X-ray binaries exhibit different spectral and timing properties in different accretion states. The X-ray outburst of a recently discovered and extraordinarily bright source, Swift J1727.8–1613, has enabled the first investigation of how the X-ray polarization properties of a source evolve with spectral state. The 2–8 keV polarization degree was previously measured by the Imaging X-ray Polarimetry
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CLEANing Cygnus A Deep and Fast with R2D2 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-07 Arwa Dabbech, Amir Aghabiglou, Chung San Chu, Yves Wiaux
A novel deep-learning paradigm for synthesis imaging by radio interferometry in astronomy was recently proposed, dubbed “Residual-to-Residual DNN series for high-Dynamic range imaging” (R2D2). In this work, we start by shedding light on R2D2's algorithmic structure, interpreting it as a learned version of CLEAN with minor cycles substituted with a deep neural network (DNN) whose training is iteration-specific
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“Extended Emission” from Fallback Accretion onto Merger Remnants Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-06 Carlo Musolino, Raphaël Duqué, Luciano Rezzolla
Using a set of general-relativistic magnetohydrodynamics simulations that include proper neutrino transfer, we assess for the first time the role played by the fallback accretion onto the remnant from a binary neutron star merger over a timescale of hundreds of seconds. In particular, we find that, independently of the equation of state, the properties of the binary, and the fate of the remnant, the
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Overmassive Black Holes at Cosmic Noon: Linking the Local and the High-redshift Universe Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-06 Mar Mezcua, Fabio Pacucci, Hyewon Suh, Malgorzata Siudek, Priyamvada Natarajan
We report for the first time a sample of 12 supermassive black holes (SMBHs) hosted by low-mass galaxies at cosmic noon, i.e., in a redshift range consistent with the peak of star formation history: z ∼ 1–3. These black holes are 2 orders of magnitude too massive for the stellar content of their hosts when compared with the local relation for active galaxies. These overmassive systems at cosmic noon
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Calcium Chemistry in Carbon-rich Circumstellar Environments: The Laboratory and Astronomical Discovery of Calcium Dicarbide, CaC2 * * This work is based on observations done using the 100 m Green Bank Telescope (GBT), the Yebes 40 m telescope (projects 19A010, 20A017, 20B014, and 21A019), and the IRAM 30 m telescope. The 100 m GBT is an instrument of the Green Bank Observatory, which is a major research Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-03 H. Gupta, P. B. Changala, J. Cernicharo, J. R. Pardo, M. Agúndez, C. Cabezas, B. Tercero, M. Guélin, M. C. McCarthy
Calcium dicarbide, CaC2, has been characterized at high resolution in the laboratory, and its main isotopologue, 40CaC2, has been assigned to 14 rotational emission lines between 14 and 115 GHz, including 12 previously unassigned lines, in the expanding molecular envelope of the evolved carbon star IRC+10216. Aided by high-level quantum calculations and measurements of multiple isotopologues, CaC2
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Evidence for Plasmoid-mediated Magnetic Reconnection during a Small-scale Flare in the Partially Ionized Low Solar Atmosphere Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-03 Guanchong Cheng, Lei Ni, Zehao Tang, Yajie Chen, Yuhao Chen, Jialiang Hu, Jun Lin
Magnetic reconnection plays a crucial role in the energy release process for different kinds of solar eruptions and activities. The rapid solar eruption requires a fast reconnection model. Plasmoid instability in the reconnecting current sheets is one of the most acceptable fast reconnection mechanisms for explaining the explosive events in the magnetohydrodynamics (MHD) scale, which is also a potential
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The Kinematic and Chemical Properties of the Close-in Planet Host Star 8 UMi Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-02 Huiling Chen, Yang Huang, Wei Zhu, Timothy C. Beers, Renjing Xie, Yutao Zhou, Sharon Xuesong Wang, Wei Wang, Sofya Alexeeva, Qikang Feng, Haozhu Fu, Haining Li, Lile Wang, Huawei Zhang
A recent study by Hon et al. reported that a close-in planet around the red clump star, 8 UMi, should have been engulfed during the expansion phase of its parent star’s evolution. They explained the survival of this exoplanet through a binary-merger channel for 8 UMi. The key to testing this formation scenario is to derive the true age of this star: is it an old “imposter” resulting from a binary merger
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Annual and Seasonal Occurrence Pattern of Auroral Kilometric Radiation Associated with the Interplanetary Magnetic Field* * Released on March 1st, 2024. Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-02 Ping Li, Sai Zhang, Fuliang Xiao, Hongming Yang, Shengyi Ye, Si Liu, Yihua He, Qiwu Yang, Jiawen Tang, Archie James Johnston
Auroral kilometric radiation (AKR) is a widely existing strong radio emission from the Earth’s magnetosphere and is generated by suprathermal (1–10 keV) electrons in the polar cavity. Previous works have demonstrated that AKR can contribute to the coupling of the magnetosphere–ionosphere–atmosphere, but its relation to the interplanetary magnetic field (IMF) has not been studied so far. Here, we examine
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Biogenic Sulfur Gases as Biosignatures on Temperate Sub-Neptune Waterworlds Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-02 Shang-Min Tsai, Hamish Innes, Nicholas F. Wogan, Edward W. Schwieterman
Theoretical predictions and observational data indicate a class of sub-Neptune exoplanets may have water-rich interiors covered by hydrogen-dominated atmospheres. Provided suitable climate conditions, such planets could host surface liquid oceans. Motivated by recent JWST observations of K2-18 b, we self-consistently model the photochemistry and potential detectability of biogenic sulfur gases in the
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Cascade Radiations of e ± from γγ-annihilation Process as an Extra Component of the Early Optical/X-Ray Afterglows of Gamma-Ray Bursts Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-02 Ren-Jie Xiong, Xiao-Li Huang, Ze-Rui Wang
Chromatic break and/or plateau observed in the early optical and X-ray afterglow lightcurves challenge the conventional external shock models of gamma-ray bursts (GRBs). Detection of TeV gamma-ray afterglows indicates strong gamma-ray production within the afterglow jets. We investigate the cascade radiations of the e ± production via the γ γ interaction in the jets. Our numerical calculations show
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JWST/MIRI Detection of Suprathermal OH Rotational Emissions: Probing the Dissociation of the Water by Lyα Photons near the Protostar HOPS 370 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-01 David A. Neufeld, P. Manoj, Himanshu Tyagi, Mayank Narang, Dan M. Watson, S. Thomas Megeath, Ewine F. Van Dishoeck, Robert A. Gutermuth, Thomas Stanke, Yao-Lun Yang, Adam E. Rubinstein, Guillem Anglada, Henrik Beuther, Alessio Caratti o Garatti, Neal J. Evans, Samuel Federman, William J. Fischer, Joel Green, Pamela Klaassen, Leslie W. Looney, Mayra Osorio, Pooneh Nazari, John J. Tobin, Łukasz Tychoniec
Using the MIRI medium-resolution spectrometer on JWST, we have detected pure rotational, suprathermal OH emissions from the vicinity of the intermediate-mass protostar HOPS 370 (OMC2/FIR3). These emissions are observed from shocked knots in a jet/outflow and originate in states of rotational quantum number as high as 46 that possess excitation energies as large as E U /k = 4.65 × 104 K. The relative
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Chandra HETG X-Ray Spectra and Variability of π Aqr, a γ Cas-type Be Star Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-05-01 David P. Huenemoerder, Pragati Pradhan, Claude R. Canizares, Sean Gunderson, Richard Ignace, Joy S. Nichols, A. M. T. Pollock, Norbert S. Schulz, Dustin K. Swarm, José M. Torrejón
High-resolution X-ray spectra of π Aqr, a γ Cas-type star, obtained with the Chandra/HETG spectrometer, revealed emission lines of H-like ions of Mg, Si, S, and Fe; a strong, hard continuum; and a lack of He-like ions, indicating the presence of very hot thermal plasma. The X-ray light curve showed significant fluctuations, with coherent variability at a period of about 3400 s in one observation. The
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Mid-infrared Spectrum of the Disk around the Forming Companion GQ Lup B Revealed by JWST/MIRI Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-30 Gabriele Cugno, Polychronis Patapis, Andrea Banzatti, Michael Meyer, Felix A. Dannert, Tomas Stolker, Ryan J. MacDonald, Klaus M. Pontoppidan
GQ Lup B is a forming brown dwarf companion (M ∼ 10–30 M J) showing evidence for an infrared excess associated with a disk surrounding the companion itself. Here we present mid-infrared (MIR) observations of GQ Lup B with the Medium Resolution Spectrometer (MRS) on JWST, spanning 4.8–11.7 μm. We remove the stellar contamination using reference differential imaging based on principal component analysis
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Cosmology with Galaxy Photometry Alone Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-30 ChangHoon Hahn, Francisco Villaescusa-Navarro, Peter Melchior, Romain Teyssier
We present the first cosmological constraints using only the observed photometry of galaxies. Villaescusa-Navarro et al. recently demonstrated that the internal physical properties of a single simulated galaxy contain a significant amount of cosmological information. These physical properties, however, cannot be directly measured from observations. In this work, we present how we can go beyond theoretical
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The Disappearance of the Blue and Luminous Progenitor of the Type IIn SN 2010jl Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-30 Zexi Niu, Ning-Chen Sun, Jifeng Liu
Type IIn supernovae (SNe) exhibit narrow hydrogen lines that arise from the strong interaction between ejecta and circumstellar material. It remains poorly understood, however, what progenitor stars give rise to these explosions. In this work, we perform a detailed analysis of the progenitor and environment of the nearby Type IIn SN 2010jl. With newer images taken by the Hubble Space Telescope, we
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Energetic Neutral Atoms Detected in the 2022 February 15 Solar Energetic Particle Event Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-30 C. M. S. Cohen, R. A. Leske, O. C. St. Cyr, G. M. Mason
Energetic neutral atoms (ENAs) are expected to be produced near the Sun during large solar energetic particle (SEP) events. However, their detection by SEP instruments near 1 au has been limited. The clearest reported measurement has been from the Solar Terrestrial Relations Observatory (STEREO) during the 2006 December 5 SEP event. Additional evidence of ENAs has been found through reanalysis of observations
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An Efficient Tidal Dissipation Mechanism via Stellar Magnetic Fields Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-29 Craig D. Duguid, Nils B. de Vries, Daniel Lecoanet, Adrian J. Barker
Recent work suggests that inwardly propagating internal gravity waves (IGWs) within a star can be fully converted to outward magnetic waves if they encounter a sufficiently strong magnetic field. The resulting magnetic waves dissipate as they propagate outward to regions with lower Alfvén velocity. While tidal forcing is known to excite IGWs, this conversion and subsequent damping of magnetic waves
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Spin Doctors: How to Diagnose a Hierarchical Merger Origin Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-26 Ethan Payne, Kyle Kremer, Michael Zevin
Gravitational-wave observations provide the unique opportunity of studying black hole formation channels and histories—but only if we can identify their origin. One such formation mechanism is the dynamical synthesis of black hole binaries in dense stellar systems. Given the expected isotropic distribution of component spins of binary black holes in gas-free dynamical environments, the presence of
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Exploring the Impact of the Aging Effect on Inferred Properties of Solar Coronal Mass Ejections Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-26 F. Regnault, N. Al-Haddad, N. Lugaz, C. J. Farrugia, B. Zhuang, W. Yu, A. Strugarek
In situ measurements of coronal mass ejections (CMEs) when they pass over an interplanetary probe are one of the main ways we directly measure their properties. However, such in situ profiles are subject to several observational constraints that are still poorly understood. This work aims at quantifying one of them, namely, the aging effect, using a CME simulated with a three-dimensional magnetohydrodynamical
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Dark No More: The Low-luminosity Stellar Counterpart of a Dark Cloud in the Virgo Cluster* * Based on observations obtained with the Hobby–Eberly Telescope (HET), which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Ludwig-Maximillians-Universitaet Muenchen, and Georg-August Universitaet Goettingen. The HET is named in honor of its principal benefactors Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-26 Michael G. Jones, Steven Janowiecki, Swapnaneel Dey, David J. Sand, Paul Bennet, Denija Crnojević, Catherine E. Fielder, Ananthan Karunakaran, Brian R. Kent, Nicolas Mazziotti, Burçin Mutlu-Pakdil, Kristine Spekkens
We have discovered the stellar counterpart to the ALFALFA Virgo 7 cloud complex, which has been thought to be optically dark and nearly star-free since its discovery in 2007. This ∼190 kpc long chain of enormous atomic gas clouds (M H i ∼ 109 M ⊙) is embedded in the hot intracluster medium of the Virgo galaxy cluster but is isolated from any galaxy. Its faint, blue stellar counterpart, BC6, was identified
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The First Quenched Galaxies: When and How? Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-21 Lizhi Xie, 利智 谢, Gabriella De Lucia, Fabio Fontanot, Michaela Hirschmann, Yannick M. Bahé, Michael L. Balogh, Adam Muzzin, Benedetta Vulcani, Devontae C. Baxter, Ben Forrest, Gillian Wilson, Gregory H. Rudnick, M. C. Cooper and Umberto Rescigno
Many quiescent galaxies discovered in the early Universe by JWST raise fundamental questions on when and how these galaxies became and stayed quenched. Making use of the latest version of the semianalytic model GAEA that provides good agreement with the observed quenched fractions up to z ∼ 3, we make predictions for the expected fractions of quiescent galaxies up to z ∼ 7 and analyze the main quenching
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Evaporation of Close-in Sub-Neptunes by Cooling White Dwarfs Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-21 Elena Gallo, Andrea Caldiroli, Riccardo Spinelli, Federico Biassoni, Francesco Haardt, Mary Anne Limbach, Juliette Becker and Fred C. Adams
Motivated by the recent surge in interest concerning white dwarf (WD) planets, this work presents the first numerical exploration of WD-driven atmospheric escape, whereby the high-energy radiation from a hot/young WD can trigger the outflow of the hydrogen–helium envelope for close-in planets. As a pilot investigation, we focus on two specific cases: a gas giant and a sub-Neptune-sized planet, both
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The Influence of Thermonuclear Bursts on Polar Caps of the Accreting X-Ray Millisecond Pulsar MAXI J1816-195 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-21 Long Ji, Mingyu Ge, Yupeng Chen, Zhaosheng Li, Peng-Ju Wang, Shu Zhang and Shuang-Nan Zhang
We report accretion-powered pulsations for the first time during thermonuclear bursts in hard X-rays, which were observed with Insight-HXMT in 2022 during the outburst of the accreting X-ray millisecond pulsar MAXI J1816-195. By stacking 73 bursts, we detected pulse profiles in 8–30 and 30–100 keV during bursts, which are identical to those obtained from the persistent (nonburst) emission. On average
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Detection of Rydberg Lines from the Atmosphere of Betelgeuse Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-25 W. R. F. Dent, G. M. Harper, A. M. S. Richards, P. Kervella, L. D. Matthews
Emission lines from Rydberg transitions are detected for the first time from a region close to the surface of Betelgeuse. The H30α line is observed at 231.905 GHz, with an FWHM ∼42 km s−1 and extended wings. A second line at 232.025 GHz (FWHM ∼21 km s−1 ), is modeled as a combination of Rydberg transitions of abundant low first ionization potential metals. Both H30α and the Rydberg combined line X30α
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Evolution of Electron Acceleration by Corotating Interaction Region Shocks at 1 au Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-25 Xinnian Guo, Linghua Wang, Wenyan Li, Qianyi Ma, Liu Yang, Robert F. Wimmer-Schweingruber, Stuart D. Bale
We present the first observations of in situ electron acceleration at corotating interaction region (CIR) shocks near 1 au, utilizing measurements from Wind and Magnetospheric Multiscale (MMS) mission in the interplanetary medium. As the forward (reverse) shock of the 2018 January CIR (the 2020 February CIR) moves from Wind at [206, 92, −7]R E ([257, 25, 3]R E ) to MMS1 at [24, 2, 7]R E ([25, 3, 0
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The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. V. Do Self-consistent Atmospheric Models Represent JWST Spectra? A Showcase with VHS 1256–1257 b Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-25 Simon Petrus, Niall Whiteford, Polychronis Patapis, Beth A. Biller, Andrew Skemer, Sasha Hinkley, Genaro Suárez, Paulina Palma-Bifani, Caroline V. Morley, Pascal Tremblin, Benjamin Charnay, Johanna M. Vos, Jason J. Wang, Jordan M. Stone, Mickaël Bonnefoy, Gaël Chauvin, Brittany E. Miles, Aarynn L. Carter, Anna Lueber, Christiane Helling, Ben J. Sutlieff, Markus Janson, Eileen C. Gonzales, Kielan K
The unprecedented medium-resolution (R λ ∼ 1500–3500) near- and mid-infrared (1–18 μm) spectrum provided by JWST for the young (140 ± 20 Myr) low-mass (12–20 M Jup) L–T transition (L7) companion VHS 1256 b gives access to a catalog of molecular absorptions. In this study, we present a comprehensive analysis of this data set utilizing a forward-modeling approach applying our Bayesian framework, ForMoSA
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Theoretical Analysis of the RX J0209.6−7427 X-Ray Spectrum during a Giant Outburst Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-24 Brent F. West, Peter A. Becker, Georgios Vasilopoulos
We model the spectral formation occurring in the binary X-ray pulsar (XRP) RX J0209.6−7427 during the 2019 super-Eddington outburst. Using a theoretical model previously developed by the authors, we are able to produce spectra that closely resemble the phase-averaged X-ray spectra observed using the Nuclear Spectroscopic Telescope Array and Insight-HXMT during low- and high-luminosity states of the
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High-resolution Spectroscopic Reconnaissance of a Temperate Sub-Neptune Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-24 Samuel H. C. Cabot, Nikku Madhusudhan, Savvas Constantinou, Diana Valencia, Johanna M. Vos, Thomas Masseron, Connor J. Cheverall
The study of temperate sub-Neptunes is the new frontier in exoplanetary science. A major development in the past year has been the first detection of carbon-bearing molecules in the atmosphere of a temperate sub-Neptune, K2-18 b, a possible Hycean world, with the James Webb Space Telescope (JWST). The JWST is poised to characterize the atmospheres of several other such planets, with important implications
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Stellar Black Holes Can “Stretch” Supermassive Black Hole Accretion Disks Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-24 Shuying Zhou, Mouyuan Sun, Tong Liu, Jian-Min Wang, Jun-Xian Wang, Yongquan Xue
Stellar black holes (sBHs) are widely believed to exist in the accretion disks of active galactic nuclei (AGNs). Previous studies often focus on the transient emission produced by embedded sBHs. Here, we explore the possible observational consequences of an AGN accretion disk that contains a population of accreting sBHs. Embedded accreting sBHs change the effective temperature distribution of the AGN
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Generation of Low-inclination, Neptune-crossing Trans-Neptunian Objects by Planet Nine Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-24 Konstantin Batygin, Alessandro Morbidelli, Michael E. Brown, David Nesvorný
The solar system’s distant reaches exhibit a wealth of anomalous dynamical structure, hinting at the presence of a yet-undetected, massive trans-Neptunian body—Planet Nine (P9). Previous analyses have shown how orbital evolution induced by this object can explain the origins of a broad assortment of exotic orbits, ranging from those characterized by high perihelia to those with extreme inclinations
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Expansion of Accreting Main-sequence Stars during Rapid Mass Transfer Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-24 Mike Y. M. Lau, Ryosuke Hirai, Ilya Mandel, Christopher A. Tout
Accreting main-sequence stars expand significantly when the mass accretion timescale is much shorter than their thermal timescales. This occurs during mass transfer from an evolved giant star onto a main-sequence companion in a binary system and is an important phase in the formation of compact binaries including X-ray binaries, cataclysmic variables, and gravitational-wave sources. In this study,
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Electron Densities of Transition Region Loops Derived from IRIS O iv Spectral Data Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-24 Shiyu Liang, Ziyuan Wang, Zhenghua Huang, Hengyuan Wei, Hui Fu, Ming Xiong, Lidong Xia
Loops are fundamental structures in the magnetized atmosphere of the Sun. Their physical properties are crucial for understanding the nature of the solar atmosphere. Transition region loops are relatively dynamic and their physical properties have not yet been fully understood. With spectral data of the line pair of O iv 1399.8 Å and 1401.2 Å ( Tmax=1.4×105 K) of 23 transition region loops obtained
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Tidal Disruption of Planetesimals from an Eccentric Debris Disk Following a White Dwarf Natal Kick Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-23 Tatsuya Akiba, Selah McIntyre, Ann-Marie Madigan
The surfaces of many white dwarfs are polluted by metals, implying a recent accretion event. The tidal disruption of planetesimals is a viable source of white dwarf pollution and offers a unique window into the composition of exoplanet systems. The question of how planetary material enters the tidal disruption radius of the white dwarf is currently unresolved. Using a series of N-body simulations,
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Negative-energy Waves in the Vertical Threads of a Solar Prominence Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-18 Jincheng Wang, Dong Li, Chuan Li, Yijun Hou, Zhike Xue, Zhe Xu, Liheng Yang, Qiaoling Li
Solar prominences, intricate structures on the Sun’s limb, have been a subject of fascination owing to their threadlike features and dynamic behaviors. Utilizing data from the New Vacuum Solar Telescope, Chinese Hα Solar Explorer, and Solar Dynamics Observatory, this study investigates the transverse swaying motions observed in the vertical threads of a solar prominence during its eruption onset on
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Simulating X-Ray Reverberation in the Ultraviolet-emitting Regions of Active Galactic Nuclei Accretion Disks with Three-dimensional Multifrequency Radiation Magnetohydrodynamic Simulations Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-17 Amy Secunda, Yan-Fei Jiang, 燕飞 姜 and Jenny E. Greene
Active galactic nuclei (AGN) light curves observed with different wave bands show that the variability in longer wavelength bands lags the variability in shorter wavelength bands. Measuring these lags, or reverberation mapping, is used to measure the radial temperature profile and extent of AGN disks, typically with a reprocessing model that assumes X-rays are the main driver of the variability in
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A JWST Survey of the Supernova Remnant Cassiopeia A Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-16 Dan Milisavljevic, Tea Temim, Ilse De Looze, Danielle Dickinson, J. Martin Laming, Robert Fesen, John C. Raymond, Richard G. Arendt, Jacco Vink, Bettina Posselt, George G. Pavlov, Ori D. Fox, Ethan Pinarski, Bhagya Subrayan, Judy Schmidt, William P. Blair, Armin Rest, Daniel Patnaude, Bon-Chul Koo, Jeonghee Rho, Salvatore Orlando, Hans-Thomas Janka, Moira Andrews, Michael J. Barlow, Adam Burrows, Roger
We present initial results from a James Webb Space Telescope (JWST) survey of the youngest Galactic core-collapse supernova remnant, Cassiopeia A (Cas A), made up of NIRCam and MIRI imaging mosaics that map emission from the main shell, interior, and surrounding circumstellar/interstellar material (CSM/ISM). We also present four exploratory positions of MIRI Medium Resolution Spectrograph integral
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Discovery of Thionylimide, HNSO, in Space: The first N-, S-, and O-bearing Interstellar Molecule Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-16 Miguel Sanz-Novo, Víctor M. Rivilla, Holger S. P. Müller, Izaskun Jiménez-Serra, Jesús Martín-Pintado, Laura Colzi, Shaoshan Zeng, Andrés Megías, Álvaro López-Gallifa, Antonio Martínez-Henares, Belén Tercero, Pablo de Vicente, David San Andrés, Sergio Martín, Miguel A. Requena-Torres
We present the first detection in space of thionylimide (HNSO) toward the Galactic center molecular cloud G + 0.693-0.027, thanks to the superb sensitivity of an ultradeep molecular line survey carried out with the Yebes 40 m and IRAM 30 m telescopes. This molecule is the first species detected in the interstellar medium containing, simultaneously, N, S, and O. We have identified numerous K a = 0,
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Tidal Disruption Encores Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-16 Taeho Ryu, Rosalba Perna, Matteo Cantiello
Nuclear star clusters (NSCs), made up of a dense concentration of stars and the compact objects they leave behind, are ubiquitous in the central regions of galaxies surrounding the central supermassive black hole (SMBH). Close interactions between stars and stellar-mass black holes (sBHs) lead to tidal disruption events (TDEs). We uncover an interesting new phenomenon: for a subset of these, the unbound
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An X-Ray Census of Active Galactic Nuclei in the Virgo and Fornax Clusters of Galaxies with SRG/eROSITA Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-15 Meicun Hou, Zhensong Hu, Zhiyuan Li
We present a uniform and sensitive X-ray census of active galactic nuclei (AGNs) in the two nearest galaxy clusters, Virgo and Fornax, utilizing the newly released X-ray source catalogs from the first all-sky scan of Spectrum-Roentgen-Gamma/eROSITA. A total of 50 and 10 X-ray sources are found positionally coincident with the nuclei of member galaxies in Virgo and Fornax, respectively, down to a 0
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Rotational Spectrum and First Interstellar Detection of 2-methoxyethanol Using ALMA Observations of NGC 6334I Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-12 Zachary T. P. Fried, Samer J. El-Abd, Brian M. Hays, Gabi Wenzel, Alex N. Byrne, Laurent Margulès, Roman A. Motiyenko, Steven T. Shipman, Maria P. Horne, Jes K. Jørgensen, Crystal L. Brogan, Todd R. Hunter, Anthony J. Remijan, Andrew Lipnicky, Ryan A. Loomis, Brett A. McGuire
We use both chirped-pulse Fourier transform and frequency-modulated absorption spectroscopy to study the rotational spectrum of 2-methoxyethanol (CH3OCH2CH2OH) in several frequency regions ranging from 8.7 to 500 GHz. The resulting rotational parameters permitted a search for this molecule in Atacama Large Millimeter/submillimeter Array (ALMA) observations toward the massive protocluster NGC 6334I
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Axial Flux Evolution of Small-scale Magnetic Flux Ropes from 0.06 to 10 au Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-11 Hameedullah Farooki, Jeongwoo Lee, Francesco Pecora, Haimin Wang, Hyomin Kim
Small-scale magnetic flux ropes (SMFRs) fill much of the solar wind, but their origin and evolution are debated. We apply our recently developed, improved Grad–Shafranov algorithm for the detection and reconstruction of SMFRs to data from Parker Solar Probe, Solar Orbiter, Wind, and Voyager 1 and 2 to detect events from 0.06 to 10 au. We observe that the axial flux density is the same for SMFRs of
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A Candidate Supermassive Black Hole in a Gravitationally Lensed Galaxy at Z ≈ 10 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-11 Orsolya E. Kovács, Ákos Bogdán, Priyamvada Natarajan, Norbert Werner, Mojegan Azadi, Marta Volonteri, Grant R. Tremblay, Urmila Chadayammuri, William R. Forman, Christine Jones, Ralph P. Kraft
While supermassive black holes (SMBHs) are widely observed in the nearby and distant Universe, their origin remains debated with two viable formation scenarios with light and heavy seeds. In the light seeding model, the seed of the first SMBHs form from the collapse of massive stars with masses of 10–100 M ⊙, while the heavy seeding model posits the formation of 104–5 M ⊙ seeds from direct collapse
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NICER, NuSTAR, and Insight-HXMT Views to Black Hole X-Ray Binary SLX 1746–331 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-11 Jing-Qiang Peng, Shu Zhang, Qing-Cang Shui, Shuang-Nan Zhang, Yu-Peng Chen, Ling-Da Kong, Zhuo-Li Yu, Long Ji, Peng-Ju Wang, Ming-Yu Ge, Jin-Lu Qu, Lian Tao, Zhi Chang, Jian Li, Zhao-sheng Li, Zhe Yan
We study the spectral and temporal properties of the black hole (BH) X-ray transient binary SLX 1746–331 during the 2023 outburst with NICER, NuSTAR, and Insight-HXMT observations. Through the joint fitting of the spectra from NICER, NuSTAR, and Insight-HXMT, the spin and inclination angles are measured for the first time as 0.85 ± 0.03 and 53° ± 0.°5, respectively. Accordingly, the mass of the compact
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Ultradeep Cover: An Exotic and Jetted Tidal Disruption Event Candidate Disguised as a Gamma-Ray Burst Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-11 R. A. J. Eyles-Ferris, C. J. Nixon, E. R. Coughlin, P. T. O’Brien
Gamma-ray bursts (GRBs) are traditionally classified as either short GRBs with durations ≲2 s that are powered by compact object mergers or long GRBs with durations ≳2 s that are powered by the deaths of massive stars. Recent results, however, have challenged this dichotomy and suggest that there exists a population of merger-driven long bursts. One such example, GRB 191019A, has a t 90 ≈ 64 s, but
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Cold Dark Matter and Self-interacting Dark Matter Interpretations of the Strong Gravitational Lensing Object JWST-ER1 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-11 Demao Kong, Daneng Yang, Hai-Bo Yu
van Dokkum et al. reported the discovery of JWST-ER1, a strong lensing object at redshift z ≈ 2, using data from the James Webb Space Telescope. The lens mass within the Einstein ring is 5.9 times higher than the expected stellar mass from a Chabrier initial mass function, indicating a high dark matter density. In this work, we show that a cold dark matter halo, influenced by gas-driven adiabatic contraction
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Vortex Fiber Nulling for Exoplanet Observations: First Direct Detection of M Dwarf Companions around HIP 21543, HIP 94666, and HIP 50319 Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-10 Daniel Echeverri, Jerry W. Xuan, John D. Monnier, Jacques-Robert Delorme, Jason J. Wang, Nemanja Jovanovic, Katelyn Horstman, Garreth Ruane, Bertrand Mennesson, Eugene Serabyn, Dimitri Mawet, J. Kent Wallace, Sofia Hillman, Ashley Baker, Randall Bartos, Benjamin Calvin, Sylvain Cetre, Greg Doppmann, Luke Finnerty, Michael P. Fitzgerald, Chih-Chun Hsu, Joshua Liberman, Ronald López, Maxwell Millar-Blanchaer
Vortex fiber nulling (VFN) is a technique for detecting and characterizing faint companions at small separations from their host star. A near-infrared (∼2.3 μm) VFN demonstrator mode was deployed on the Keck Planet Imager and Characterizer (KPIC) instrument at the Keck Observatory and presented earlier. In this Letter, we present the first VFN companion detections. Three targets, HIP 21543 Ab, HIP
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Discovery of the Longest-period Classical Cepheid in the Milky Way Astrophys. J. Lett. (IF 7.9) Pub Date : 2024-04-10 I. Soszyński, D. M. Skowron, A. Udalski, P. Pietrukowicz, M. Gromadzki, M. K. Szymański, J. Skowron, P. Mróz, R. Poleski, S. Kozłowski, P. Iwanek, M. Wrona, K. Ulaczyk, K. Rybicki, M. Mróz
We report the discovery of the classical Cepheid OGLE-GD-CEP-1884 (= GDS_J1535467-555656) with the longest pulsation period known in our Galaxy. The period of 78.14 days is nearly 10 days longer than that of the previous record-holding Cepheid, S Vulpeculae, and thus, OGLE-GD-CEP-1884 can be categorized as the first ultra-long-period Cepheid in the Milky Way. This star is present in the ASAS-SN and