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Wind shear and the role of eddy vapor transport in driving water convection on Jupiter Ramanakumar Sankar, Michael H Wong, Csaba Palotai, Shawn Brueshaber arXiv:2505.17213v1 Announce Type: new Abstract: Recent observations of convection in the jovian atmosphere have demonstrated that convection is strongly concentrated at specific locations on planet. For instance, observations of lightning show that the cyclonic features (e.g,. belts and folded filamentary regions – FFRs) show increased convective activity compared to anti-cyclonic regions. Meanwhile, the distribution of ammonia and water vapor show a large enrichment near the equator, which is also suggestive of strong upwelling and convective activity. Marrying these different observations isRead More →

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Quintessence: an analytical study, with theoretical and observational applications David Andriot arXiv:2410.17182v2 Announce Type: replace-cross Abstract: We focus on minimally coupled (multi)field quintessence models, of thawing type, and their realistic solutions. In a model-independent manner, we describe analytically these cosmological solutions throughout the universe history. Starting with a kination – radiation domination phase, we obtain an upper bound on the scalar potential to guarantee an early kination: $V(varphi) ll e^{-sqrt{6} varphi}$. Turning to the radiation – matter phase, we obtain analytic expressions for the scale factor $a(t)$ (not $t(a)$) and the scalar fields $varphi^i(t)$ (usually neglected). These allow us to evaluate analytically the freezing ofRead More →

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The Backup Program of the Dark Energy Spectroscopic Instrument’s Milky Way Survey Arjun Dey, Sergey E. Koposov, Joan R. Najita, Andrew P. Cooper, B. T. G"ansicke, Adam D. Myers, A. Raichoor, Daniel J. Eisenstein, E. F. Schlafly, C. Allende Prieto, Leandro Beraldo e Silva, Ting S. Li, M. Valluri, St’ephanie Juneau, Mika Lambert, S. Li, Guillaume F. Thomas, Wenting Wang, Alexander H. Riley, N. Kizhuprakkat, J. Aguilar, S. Ahlen, S. Bailey, D. Bianchi, D. Brooks, T. Claybaugh, A. Cuceu, A. de la Macorra, J. Della Costa, Biprateep Dey, P. Doel, A. Font-Ribera, J. E. Forero-Romero, E. Gazta~naga, S. Gontcho A Gontcho, G. Gutierrez, J. Guy,Read More →

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On the global Gaussian bending measure and its applications in stationary spacetimes Zhen Zhang, Rui Zhang arXiv:2408.02195v2 Announce Type: cross Abstract: Modified gravity theories have been suggested to address the limitations of general relativity, each exhibiting differences, particularly in their strong-field limits. Nonetheless, there lacks effective means to distinguish or test these theories through local strong-field measurements. In this work, we define a global Gaussian bending measure over singular spacetime regions, establish a corresponding global theory, and demonstrate its applications in a general stationary spacetime. The global theory is based on differential geometry, rather than on specific gravity theories, allowing it to depict various physicsRead More →

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Oort Cloud Formation and Evolution in Star Clusters Justine C. Obidowski, Jeremy J. Webb, Simon Portegies Zwart, Maxwell X. Cai arXiv:2505.17246v1 Announce Type: new Abstract: It is unknown if an Oort cloud reaches its maximum mass within its star’s birth cluster or millions of years later. Complicating the Oort cloud evolution process is the fact that comets can be stripped from orbit due to perturbations from passing stars. We explore how a star’s cluster escape time (t$_{ rm esc}$) and the time its Oort cloud reaches maximum mass (t$_{ rm max}$) affect the Oort cloud’s ability to survive via $N$-body simulations. In a 14 M$_odot$/pc$^3$Read More →

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The impact of compact object deformation on thin accretion disk properties Shokoufe Faraji arXiv:2505.17924v1 Announce Type: cross Abstract: We investigate the standard relativistic geometrically thin and optically thick accretion disk in the background of a deformed compact object. The main purpose of this work is to determine whether such a deformed object possesses its own observational fingerprint that can distinguish it from Schwarzschild and Kerr black holes. Our analysis reveals the properties of this relativistic accretion disk model and its dependence on the initial parameters.arXiv:2505.17924v1 Announce Type: cross Abstract: We investigate the standard relativistic geometrically thin and optically thick accretion disk in the background ofRead More →

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A Joint Analysis of Strong Lensing and Type Ia Supernovae to Determine the Hubble Constant L. R. Colac{c}o, R. F. L. Holanda, Z. C. Santana, R. Silva arXiv:2505.17262v1 Announce Type: new Abstract: We present a cosmological model-independent determination of the Hubble constant, $H_0$, by combining time-delay measurements from seven TDCOSMO systems, Einstein radius measurements, and Type Ia Supernovae data sourced from the Pantheon+ sample. For each lens of time-delay system, we calculate the angular diameter distance $D_{A_l}$ using the product $D^{textrm{Obs}}(z_l) cdot D_{A,Delta t}^{textrm{Obs}}(z_l, z_s)$, where $D^{textrm{Obs}}(z_l)$ is reconstructed via Gaussian Processes from 99 Einstein radius measurements, and $D_{A,Delta t}^{textrm{Obs}}(z_l,z_s)$ is the time-delay angular distance.Read More →

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Astronomers Conduct a Preliminary Search for Exoplanets Around Alpha Centauri An international team of researchers has announced the preliminary findings of Webb’s observations of the Alpha Centauri system. According to their analysis, Alpha Cen A may have a Jupiter-sized planet and a very bright zodiacal dust disk orbiting it. Universe Today Go to SourceRead More →

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How To Resolve Conflicts Over Lunar Resources Sometimes, space enthusiasts blind themselves with techno-optimism about all the potential cool technological things we can do and the benefits they can offer humanity. We conveniently ignore that there are trade-offs: if one group gets to utilize the water available on the lunar surface, that means another group doesn’t get to. Recognizing and attempting to come up with a plan to deal with those sorts of trade-offs is the intent of a new paper by Marissa Herron and Therese Jones of NASA’s Office of Technology, Policy, and Strategy, as well as Amanda Hernandez of BryceTech, a contractor basedRead More →

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Binary star system with millisecond pulsar and a helium star companion discovered A large team of astronomers and astrophysicists affiliated with several institutions in China has discovered a binary star system, where one of the stars is a millisecond pulsar and the other is made mostly of helium. In their paper published in the journal Science, the group describes how they discovered that a pulsar under study since 2020 had a companion star—one that was gravitationally bound to it. phys.org Go to SourceRead More →

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Hubble spies inclined spiral galaxy NGC 3511 The stately and inclined spiral galaxy NGC 3511 is the subject of this NASA/ESA Hubble Space Telescope image. The galaxy is located 43 million light-years away in the constellation Crater (The Cup). From Hubble’s vantage point in orbit around Earth, NGC 3511 is tilted by about 70 degrees, intermediate between face-on galaxies that display the full disk of the spiral and its arms, and edge-on galaxies that offer a side view, revealing only their dense, flattened disks. phys.org Go to SourceRead More →

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Pairs of stars that orbit each other exhibit unexpected magnetic activity A new study published in Nature Astronomy, led by Dr. Jie Yu, from the Australian National University, reveals that stars in close binary systems—pairs of stars orbiting each other at close range—can exhibit unexpectedly high levels of magnetic activity. phys.org Go to SourceRead More →

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Detecting the primordial black holes that could be today’s dark matter Besides particles like sterile neutrinos, axions and weakly interacting massive particles (WIMPs), a leading candidate for the cold dark matter of the universe are primordial black holes—black holes created from extremely dense conglomerations of subatomic particles in the first seconds after the Big Bang. phys.org Go to SourceRead More →

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DarkNESS: A skipper-CCD NanoSatellite for Dark Matter Searches Phoenix Alpine, Samriddhi Bhatia, Ana M. Botti, Brenda A. Cervantes-Vergara, Claudio R. Chavez, Fernando Chierchie, Alex Drlica-Wagner, Rouven Essig, Juan Estrada, Erez Etzion, Roni Harnik, Terry Kim, Michael Lembeck, Qi Lim, Bernard J. Rauscher, Nathan Saffold, Javier Tiffenberg, Sho Uemura, Hailin Xu arXiv:2505.16981v1 Announce Type: new Abstract: The Dark matter Nanosatellite Equipped with Skipper Sensors (DarkNESS) deploys a recently developed skipper-CCD architecture with sub-electron readout noise in low Earth orbit (LEO) to investigate potential signatures of dark matter (DM). The mission addresses two interaction channels: electron recoils from strongly interacting sub-GeV DM and X-rays produced through decayingRead More →

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In: arXiv

Effects of black hole environments on extreme mass-ratio hyperbolic encounters Ya-Ze Cheng, Yan Cao, Yong Tang arXiv:2411.03095v3 Announce Type: replace-cross Abstract: Extreme mass-ratio hyperbolic encounters (EMRHEs) around the supermassive black holes will be observable at the future gravitational-wave (GW) detectors in space, such as LISA and Taiji. Here we consider such EMRHEs in the presence of surrounding matter distribution including baryonic accretion disk and dark matter (DM) spike, and estimate their effects on the orbital evolution and GW waveforms. We find that large possible impacts come from the gravitational potential of accretion disk, while the influence of DM spike is small. We also illustrate thatRead More →

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Redshift leverage for the search of GRB neutrinos affected by quantum properties of spacetime Giovanni Amelino-Camelia, Giacomo D’Amico, Vittorio D’Esposito, Giuseppe Fabiano, Domenico Frattulillo, Giulia Gubitosi, Dafne Guetta, Alessandro Moia, Giacomo Rosati arXiv:2501.13840v2 Announce Type: replace-cross Abstract: Some previous studies based on IceCube neutrinos had found intriguing preliminary evidence that some of them might be GRB neutrinos with travel times affected by quantum properties of spacetime delaying them proportionally to their energy, an effect often labeled as “quantum-spacetime-induced in-vacuo dispersion”. Those previous studies looked for candidate GRB neutrinos in a fixed (neutrino-energy-independent) time window after the GRB onset and relied rather crucially on crude estimatesRead More →

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Predicting the cryogenic performance of superconducting detectors by their visual properties K. R. Ferguson, A. N. Bender, N. Whitehorn, P. S. Barry, T. W. Cecil, K. R. Dibert, E. S. Martsen arXiv:2501.02357v2 Announce Type: replace Abstract: The testing and quality assurance of cryogenic superconducting detectors is a time- and labor-intensive process. As experiments deploy increasingly larger arrays of detectors, new methods are needed for performing this testing quickly. Here, we propose a process for flagging under-performing detector wafers before they are ever tested cryogenically. Detectors are imaged under an optical microscope, and computer vision techniques are used to analyze the images, searching for visual defectsRead More →