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Supernova 1987A’s keyhole: A long-lived jet-pair in the final explosion phase of core-collapse supernovae Noam Soker (Technion, Israel) arXiv:2404.07455v1 Announce Type: new Abstract: I further study the manner by which a pair of opposite jets shape the `keyhole’ morphological structure of the core-collapse supernova (CCSN) SN 1997A, now the CCSN remnant (CCSNR) 1987A. By doing so, I strengthen the claim that the jittering-jet explosion mechanism (JJEM) accounts for most, likely all, CCSNe. The `keyhole’ structure comprises a northern low-intensity zone closed with a bright rim on its front and an elongated low-intensity nozzle in the south. This rim-nozzle asymmetry is observed in some cooling flowRead More →

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Emission-line galaxies at $zsim1$ from near-IR HST Slitless Spectroscopy: metallicities, star formation rates and redshift confirmations from VLT/FORS2 spectroscopy K. Boyett, A. J. Bunker, J Chevallard, A. J. Battisti, A. L. Henry, S. Wilkins, M. A. Malkan, J. Caruana, H. Atek, I. Baronchelli, J. Colbert, Jonathan. P. Gardner, M. Rafelski, C. Scarlata, H. I. Teplitz, X. Wang arXiv:2404.07497v1 Announce Type: new Abstract: We follow up emission line galaxies identified through the near-infrared slitless HST/WFC3 WISP survey with VLT/FORS2 optical spectroscopy. Over 4 WISP fields, we targetted 85 of 138 line emission objects at $0.4arXiv:2404.07497v1 Announce Type: new Abstract: We follow up emission line galaxies identifiedRead More →

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In: arXiv

X-ray polarimetric features of Gamma-ray Bursts across varied redshifts and hints for Axion-Like-Particles Qingxiang Zhang, Feng Huang, Zhongxiang Wang, Taotao Fang arXiv:2404.07555v1 Announce Type: new Abstract: Polarimetric features during the prompt phase of Gamma-ray Bursts (GRBs) have been essential for elucidating the debated emission mechanisms and gaining insight into the inner structure of GRBs. However, the potential impact of photon-Axion-Like-Particle (ALP) mixing in extragalactic magnetic fields, leading to significant modifications to the initial polarization state, has been overlooked in discussions concerning prompt phase constraints. In this work, we first examine the statistical characteristics of linear polarization degree ($Pi_{L}$) in GRBs, by utilizing data from polarimetricRead More →

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Orbital dynamics in the GG Tau A system: investigating its enigmatic disc Claudia Toci, Simone Ceppi, Nicol’as Cuello, Gaspard Duch^ene, Enrico Ragusa, Giuseppe Lodato, Francesca Farina, Franc{c}ois M’enard, Hossam Aly arXiv:2404.07565v1 Announce Type: new Abstract: GG Tau is one of the most studied multiple young stellar systems: GG Tau A is a hierarchical triple surrounded by a massive disc and its companion, GG Tau B, is also a binary. Despite numerous observational attempts, an understanding of the geometry of the GG Tau A system is still elusive. We provide new astrometric measures of the system and we run a set of hydrodynamical simulations with twoRead More →

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Evolution of rotating massive stars adopting a newer, self-consistent wind prescription at SMC metallicity Alex Camilo Gormaz-Matamala, Jorge Cuadra, Sylvia Ekstr"om, Georges Meynet, Michel Cur’e, Krzysztof Belczynski arXiv:2404.07570v1 Announce Type: new Abstract: We use Geneva-evolution-code to run evolutionary tracks for stellar masses ranging from $20$ to $85$ $M_odot$ at SMC metallicity ($Z=0.002$). We upgrade the recipe for stellar winds by adopting our self-consistent m-CAK prescription, which reduces the value of mass-loss rate by a factor between 2 and 6 depending on the mass range. The impact of our new winds is wide, and it can be divided between direct and indirect impact. For the mostRead More →

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CN and CCH derivatives of ethylene and ethane: Confirmation of the detection of CH$_3$CH$_2$CCH in TMC-1 J. Cernicharo, B. Tercero, M. Ag’undez, C. Cabezas, R. Fuentetaja, N. Marcelino, P. de Vicente arXiv:2404.07585v1 Announce Type: new Abstract: We present a study of CH$_3$CH$_2$CCH, CH$_3$CH$_2$CN, CH$_2$CHCCH, and CH$_2$CHCN in TMC-1 using the QUIJOTE$^1$ line survey. We confirm the presence of CH$_3$CH$_2$CCH in TMC-1, which was previously reported as tentative by our group. From a detailed study of the ethynyl and cyanide derivatives of CH$_2$CH$_2$ and CH$_3$CH$_3$ in TMC-1, we found that the CH$_2$CHCCH/CH$_2$CHCN and CH$_3$CH$_2$CCH/CH$_3$CH$_2$CN abundance ratios are 1.5$pm$0.1 and 4.8$pm$0.5, respectively. The derived CH$_2$CHCCH/CH$_3$CH$_2$CCH abundance ratioRead More →

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In: arXiv

Addition of the Local Volume sample of galaxies from the FAST HI survey Igor D. Karachentsev, Valentina E. Karachentseva, Serafim S. Kaisin, Chuan-Peng Zhang arXiv:2404.07636v1 Announce Type: new Abstract: We report the discovery of 20 new dwarf galaxies in the Local Volume identified as optical counterparts to the Five-hundred-meter Aperture Spherical radio Telescope (FAST) All Sky HI Survey (FASHI) sources. The galaxies have a median stellar mass of $7.8times 10^6~M_{odot}$ and a median HI mass of $1.0times 10^7~M_{odot}$. Most of them are field galaxies while three are probable members of M 101 and M 106 groups. We also found seven FASHI radio sources to beRead More →

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In: arXiv

Kinematics $&$ Star Formation in the Hub-Filament System G6.55-0.1 Saurav Sen (TIFR, Mumbai, India), Bhaswati Mookerjea (TIFR, Mumbai, India), Rolf Guesten (MPIfR, Bonn), Friedrich Wyrowski (MPIfR, Bonn), C. H Ishwara Chandra (NCRA-TIFR, Pune, India) arXiv:2404.07640v1 Announce Type: new Abstract: Hub-filament systems (HFSs) being the potential sites of formation of star clusters and high mass stars, provide a test bed for the current theories that attempt to explain star formation globally. It is thus important to study a large number of HFSs using both intensity and velocity information to constrain these objects better observationally. We present here a study of the hub-filament system associated with G6.55-0.1Read More →

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In: arXiv

Venus Cedric Gillmann, Giada N. Arney, Guillaume Avice, M. D. Dyar, Gregor J. Golabek, Anna J. P. Gulcher, Natasha M. Johnson, Maxence Lefevre, Thomas Widemann arXiv:2404.07669v1 Announce Type: new Abstract: After decades of relative neglect, interest in Venus surges anew in the planetary science community and the public. New missions are planned and selected, and will pave the way to the decade of Venus, as new observations allow us to uncover some of the many mysteries our closest Solar System neighbor still harbors. Building on the legacy of past works, here, we discuss the state of our understanding of Venus, from both observation and modeling.Read More →

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NASA is Building an Electrodynamic Shield to Deal with all that Dust on the Moon and Mars Exploration of the Moon or other dusty environments comes with challenges. The lunar surface is covered in material known as regolith and its a jaggy, glassy material. It can cause wear and tear on equipment and can pose a health risk to astronauts too. Astronauts travelling to Mars would experience dust saucing to everything, including solar panels leading to decrease in power. To combat the problems created by dust, NASA is working on an innovative electrodynamic dust shield to remove dust and protect surfaces from solar panels toRead More →

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Stellar winds of three sun-like stars detected for the first time An international research team led by a researcher from the University of Vienna has for the first time directly detected stellar winds from three sun-like stars by recording the X-ray emission from their astrospheres, and placed constraints on the mass loss rate of the stars via their stellar winds. phys.org Go to SourceRead More →

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Did An Ancient Icy Impactor Create the Martian Moons? The Martian moons Phobos and Deimos are oddballs. While other Solar System moons are round, Mars’ moons are misshapen and lumpy like potatoes. They’re more like asteroids or other small bodies than moons. Because of their odd shapes and unusual compositions, scientists are still puzzling over their origins. Two main hypotheses attempt to explain Phobos and Deimos. One says they’re captured asteroids, and the other says they are debris from an ancient impactor that collided with Mars. Earth’s moon was likely formed by an ancient collision when a planetesimal slammed into Earth, so there’s precedent forRead More →

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Juice aces Callisto flyby test Seven years from now, in April 2031, ESA’s Juice mission will fly past Jupiter’s moon Callisto, offering scientists a tantalizing glimpse at the mysterious, cratered alien world. phys.org Go to SourceRead More →

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Beautiful nebula, violent history: clash of stars solves stellar mystery When astronomers looked at a stellar pair at the heart of a stunning cloud of gas and dust, they were in for a surprise. Star pairs are typically very similar, like twins, but in HD 148937, one star appears younger and, unlike the other, is magnetic. New data from the European Southern Observatory (ESO) suggest there were originally three stars in the system, until two of them clashed and merged. This violent event created the surrounding cloud and forever altered the system’s fate. ESO News Feed Go to SourceRead More →

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NASA’s Next Solar Sail is About to Go to Space Everyone knows that solar energy is free and almost limitless here on Earth. The same is true for spacecraft operating in the inner Solar System. But in space, the Sun can do more than provide electrical energy; it also emits an unending stream of solar wind. Solar sails can harness that wind and provide propulsion for spacecraft. NASA is about to test a new solar sail design that can make solar sails even more effective. Solar pressure pervades the entire Solar System. It weakens with distance, but it’s present. It affects all spacecraft, including satellites.Read More →