abstract stringlengths 3 192k | title stringlengths 4 857 |
|---|---|
the relation of activity to rotation in m dwarfs is of high astrophysical interest because it provides observational evidence of the stellar dynamo, which is poorly understood for low-mass stars, especially in the fully convective regime. previous studies have shown that the relation of x-ray activity to rotation consi... | relation of x-ray activity and rotation in m dwarfs and predicted time-evolution of the x-ray luminosity |
we present an estimate of the occurrence rate of hot jupiters (7 r ⊕ ≤ rp≤ 2 r j, 0.8 ≤ pb≤ 10 days) around early-type m dwarfs based on stars observed by the transiting exoplanet survey satellite (tess) during its primary mission. we adopt stellar parameters from the tess input catalog and construct a sample of 60,819... | occurrence rate of hot jupiters around early-type m dwarfs based on transiting exoplanet survey satellite data |
numerous solar system atmospheres possess photochemically generated hazes, including the characteristic organic hazes of titan and pluto. haze particles substantially impact atmospheric temperature structures and may provide organic material to the surface of a world, potentially affecting its habitability. observation... | haze production rates in super-earth and mini-neptune atmosphere experiments |
we present high-angular-resolution imaging observations of 517 host stars of tess exoplanet candidates using the 'alopeke and zorro speckle cameras at gemini north and south. the sample consists mainly of bright f, g, k stars at distances of less than 500 pc. our speckle observations span angular resolutions of ~20 mas... | speckle observations of tess exoplanet host stars. ii. stellar companions at 1-1000 au and implications for small planet detection |
the esa-jaxa bepicolombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. many scientific instruments onboard t... | investigating mercury's environment with the two-spacecraft bepicolombo mission |
there are plenty of ways available for synthesis and analysis of planetary gear trains (pgts) of one dof. however, every method has its own shortcomings. in this paper a comparison is made between characteristic polynomial, eigenvalues and eigenvectors, hamming number method and modified path matrix (mpm) method. there... | comparison of tests for isomorphism in planetary gear trains |
meandering rivers are diagnostic landforms of hydrologically active planets, and their migration regulates the continental component of biogeochemical cycles that stabilize climate and allow for life on earth. the rise of river meanders on earth has been linked to riverbank stabilization driven by the palaeozoic evolut... | a tenfold slowdown in river meander migration driven by plant life |
the oxidation of fossil fuels produces billions of tons of anthropogenic carbon dioxide (co2) emissions from stationary and nonstationary sources per annum, contributing to global warming. the natural carbon cycle consumes a portion of co2 emissions from the atmosphere. in contrast, substantial co2 emissions accumulate... | recent advances in carbon dioxide geological storage, experimental procedures, influencing parameters, and future outlook |
the madden-julian oscillation (mjo) and the boreal summer intraseasonal oscillation (bsiso) are fundamental modes of variability in the tropical atmosphere on the intraseasonal time scale. a linear model, using a moist shallow water equation set on an equatorial beta plane, is developed to provide a unified treatment o... | a unified moisture mode theory for the madden-julian oscillation and the boreal summer intraseasonal oscillation |
aerosol-cloud interactions (aerosol indirect effects) play an important role in regional meteorological variations, which could further induce feedback on regional air quality. while the impact of aerosol-cloud interactions on meteorology and climate has been extensively studied, their feedback on air quality remains u... | enhanced pm2.5 pollution in china due to aerosol-cloud interactions |
this study evaluates the performance of urban schemes integrated in the weather research and forecasting model (wrf) using local climate zones (lcz) as land use classification. we applied two multi-layer urban schemes: 1) building effect parameterization (bep) and 2) building energy model coupled with bep (bep + bem), ... | highly resolved wrf-bep/bem simulations over barcelona urban area with lcz |
due to the very dense atmosphere, the first data on the surface of venus were obtained only by radar methods. then the information was supplemented by photos at the landing sites of spacecraft. the surface relief turned out to be diverse in shape, height difference and physical properties. the most common type of surfa... | features of volcanic structures on venus |
context. the new carmenes instrument comprises two high-resolution and high-stability spectrographs that are used to search for habitable planets around m dwarfs in the visible and near-infrared regime via the doppler technique.aims: characterising our target sample is important for constraining the physical properties... | the carmenes search for exoplanets around m dwarfs. photospheric parameters of target stars from high-resolution spectroscopy |
saturn's moon enceladus is erupting a plume of gas and ice grains from its south pole. linked directly to the moon's subsurface global ocean, plume material travels through cracks in the icy crust and is ejected into space. the subsurface ocean is believed to be in contact with the rocky core, with ongoing hydrothermal... | low-mass nitrogen-, oxygen-bearing, and aromatic compounds in enceladean ice grains |
the discovery of the first interstellar object passing through the solar system, 1i/2017 u1 (`oumuamua), provoked intense and continuing interest from the scientific community and the general public. the faintness of `oumuamua, together with the limited time window within which observations were possible, constrained t... | the natural history of `oumuamua |
we present the open-source radiative transfer code named helios, which is constructed for studying exoplanetary atmospheres. in its initial version, the model atmospheres of helios are one-dimensional and plane-parallel, and the equation of radiative transfer is solved in the two-stream approximation with nonisotropic ... | helios: an open-source, gpu-accelerated radiative transfer code for self-consistent exoplanetary atmospheres |
we analyse spatially resolved alma observations at 0.9, 1.3, and 3.1 mm for the 26 brightest protoplanetary discs in the lupus star-forming region. we characterize the discs multiwavelength brightness profiles by fitting the interferometric visibilities in a homogeneous way, obtaining effective disc sizes at the three ... | multiwavelength continuum sizes of protoplanetary discs: scaling relations and implications for grain growth and radial drift |
we present an overview and first results from a m-band spectroscopic survey of planet-forming disks performed with ishell on the infrared telescope facility, using two slits that provide resolving power r ≈ 60,000-92,000 (5-3.3 km s-1). ishell provides a nearly complete coverage at 4.52-5.24 μm in one shot, covering &g... | scanning disk rings and winds in co at 0.01-10 au: a high-resolution m-band spectroscopy survey with irtf-ishell |
we present an open-source and validated chemical kinetics code for studying hot exoplanetary atmospheres, which we name vulcan. it is constructed for gaseous chemistry from 500 to 2500 k, using a reduced c-h-o chemical network with about 300 reactions. it uses eddy diffusion to mimic atmospheric dynamics and excludes p... | vulcan: an open-source, validated chemical kinetics python code for exoplanetary atmospheres |
the first james webb space telescope observations of trappist-1 c showed a secondary eclipse depth of 421 ± 94 ppm at 15 μm, which is consistent with a bare rock surface or a thin, o2-dominated, low-co2 atmosphere. here we further explore potential atmospheres for trappist-1 c by comparing the observed secondary eclips... | potential atmospheric compositions of trappist-1 c constrained by jwst/miri observations at 15 μm |
we present a catalog of cool dwarf targets (v-j> 2.7, t eff ≲ 4000 k) and their stellar properties for the upcoming transiting exoplanet survey satellite (tess), for the purpose of determining which cool dwarfs should be observed using two minute observations. tess has the opportunity to search tens of thousands of ... | a catalog of cool dwarf targets for the transiting exoplanet survey satellite |
a new family classification, based on a catalog of proper elements with ∼384,000 numbered asteroids and on new methods is available. for the 45 dynamical families with >250 members identified in this classification, we present an attempt to obtain statistically significant ages: we succeeded in computing ages for 37... | asteroid family ages |
context. gas giants orbiting close to hot and massive early-type stars can reach dayside temperatures that are comparable to those of the coldest stars. these `ultra-hot jupiters' have atmospheres made of ions and atomic species from molecular dissociation and feature strong day-to-night temperature gradients. photomet... | the atmosphere and architecture of wasp-189 b probed by its cheops phase curve |
aims: to understand and compare the 3d atmospheric structure of hd 209458 b and hd 189733 b, focusing on the formation and distribution of cloud particles, as well as their feedback on the dynamics and thermal profile.methods: we coupled the 3d met office unified model (um), including detailed treatments of atmospheric... | simulating the cloudy atmospheres of hd 209458 b and hd 189733 b with the 3d met office unified model |
we report the discovery and characterization of a pair of sub-neptunes transiting the bright k-dwarf toi-1064 (tic 79748331), initially detected in the transiting exoplanet survey satellite (tess) photometry. to characterize the system, we performed and retrieved the characterising exoplanets satellite (cheops), tess, ... | a pair of sub-neptunes transiting the bright k-dwarf toi-1064 characterized with cheops |
the formation of a primordial crust is a critical step in the evolution of terrestrial planets but the timing of this process is poorly understood. the mineral zircon is a powerful tool for constraining crust formation because it can be accurately dated with the uranium-to-lead (u-pb) isotopic decay system and is resis... | evidence for extremely rapid magma ocean crystallization and crust formation on mars |
the familiar axisymmetric zones and belts that characterize jupiter’s weather system at lower latitudes give way to pervasive cyclonic activity at higher latitudes. two-dimensional turbulence in combination with the coriolis β-effect (that is, the large meridionally varying coriolis force on the giant planets of the so... | clusters of cyclones encircling jupiter’s poles |
in climate models, subgrid parameterizations of convection and clouds are one of the main causes of the biases in precipitation and atmospheric circulation simulations. in recent years, due to the rapid development of data science, machine learning (ml) parameterizations for convection and clouds have been demonstrated... | stable climate simulations using a realistic general circulation model with neural network parameterizations for atmospheric moist physics and radiation processes |
the global human settlement layer (ghsl) produces new global spatial information, evidence-based analytics describing the human presence on the planet that is based mainly on two quantitative factors: (i) the spatial distribution (density) of built-up structures and (ii) the spatial distribution (density) of resident p... | principles and applications of the global human settlement layer as baseline for the land use efficiency indicator—sdg 11.3.1 |
the newly detected trappist-1 system, with seven low-mass, roughly earth-sized planets transiting a nearby ultra-cool dwarf, is one of the most important exoplanet discoveries to date. the short baseline of the available discovery observations, however, means that the planetary masses (obtained through measurement of t... | updated masses for the trappist-1 planets |
the nearby exoplanet proxima centauri b will be a prime future target for characterization, despite questions about its retention of water. climate models with static oceans suggest that proxima b could harbor a small dayside surface ocean despite its weak instellation. we present the first climate simulations of proxi... | habitable climate scenarios for proxima centauri b with a dynamic ocean |
studies of planetary atmospheric composition, variability, and evolution require appropriate theoretical and numerical tools to estimate key atmospheric parameters, among which the mass-loss rate is often the most important. in evolutionary studies, it is common to use the energy-limited formula, which is attractive fo... | overcoming the limitations of the energy-limited approximation for planet atmospheric escape |
motivated by observed structure of madden-julian oscillation (mjo), a general theoretical model framework is advanced for understanding fundamental aspects of mjo dynamics. the model extends the matsuno-gill theory by incorporating (a) moisture feedback to precipitation, (b) a trio-interaction among equatorial waves, b... | a general theoretical framework for understanding essential dynamics of madden-julian oscillation |
the remote sounding of infrared emission from planetary atmospheres using limb-viewing geometry is a powerful technique for deriving vertical profiles of structure and composition on a global scale. compared with nadir viewing, limb geometry provides enhanced vertical resolution and greater sensitivity to atmospheric c... | two-dimensional radiative transfer for the retrieval of limb emission measurements in the martian atmosphere |
the next step on the path toward another earth is to find atmospheres similar to those of earth and venus—high-molecular-weight (secondary) atmospheres—on rocky exoplanets. many rocky exoplanets are born with thick (>10 kbar) h2-dominated atmospheres but subsequently lose their h2; this process has no known solar sy... | exoplanet secondary atmosphere loss and revival |
the signature of wind patterns caused by the interplay of rotation and energy redistribution in hot jupiters is detectable at high spectral resolution, yet no direct comparison has been attempted between predictions from general circulation models (gcms) and observed high-resolution spectra. we present the first such c... | the high-resolution transmission spectrum of hd 189733b interpreted with atmospheric doppler shifts from three-dimensional general circulation models |
coronal mass ejections (cmes) are the major space weather drivers, and an accurate modeling of their onset and propagation up to 1 au represents a key issue for more reliable space weather forecasts. in this paper we use the newly developed european heliospheric forecasting information asset (euhforia) heliospheric mod... | effect of the initial shape of coronal mass ejections on 3-d mhd simulations and geoeffectiveness predictions |
context. 51 eridani b is an exoplanet around a young (20 myr) nearby (29.4 pc) f0-type star, which was recently discovered by direct imaging. it is one of the closest direct imaging planets in angular and physical separation ( 0.5'', 13 au) and is well suited for spectroscopic analysis using integral field spectrograph... | spectral and atmospheric characterization of 51 eridani b using vlt/sphere |
we present new methodological features and physical ingredients included in the one-dimensional radiative transfer code helios, improving the hemispheric two-stream formalism. we conduct a thorough intercomparison survey with several established forward models, including cooltlusty and phoenix, and find satisfactory co... | self-luminous and irradiated exoplanetary atmospheres explored with helios |
we report the discovery of a new kepler transiting circumbinary planet (cbp). this latest addition to the still-small family of cbps defies the current trend of known short-period planets orbiting near the stability limit of binary stars. unlike the previous discoveries, the planet revolving around the eclipsing binary... | kepler-1647b: the largest and longest-period kepler transiting circumbinary planet |
quantum algorithms offer significant speed-ups over their classical counterparts for a variety of problems. the strongest arguments for this advantage are borne by algorithms for quantum search, quantum phase estimation, and hamiltonian simulation, which appear as subroutines for large families of composite quantum alg... | grand unification of quantum algorithms |
enabling effective and efficient machine learning (ml) over large-scale graph data (e.g., graphs with billions of edges) can have a great impact on both industrial and scientific applications. however, existing efforts to advance large-scale graph ml have been largely limited by the lack of a suitable public benchmark.... | ogb-lsc: a large-scale challenge for machine learning on graphs |
the shapes of asteroids reflect interplay between their interior properties and the processes responsible for their formation and evolution as they journey through the solar system. prior to the osiris-rex (origins, spectral interpretation, resource identification, and security-regolith explorer) mission, earth-based r... | shape of (101955) bennu indicative of a rubble pile with internal stiffness |
the hayabusa2 spacecraft arrived at the near-earth carbonaceous asteroid 162173 ryugu in 2018. we present hayabusa2 observations of ryugu’s shape, mass, and geomorphology. ryugu has an oblate “spinning top” shape, with a prominent circular equatorial ridge. its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indi... | hayabusa2 arrives at the carbonaceous asteroid 162173 ryugu—a spinning top-shaped rubble pile |
nasa's origins, spectral interpretation, resource identification and security-regolith explorer (osiris-rex) spacecraft recently arrived at the near-earth asteroid (101955) bennu, a primitive body that represents the objects that may have brought prebiotic molecules and volatiles such as water to earth1. bennu is a low... | the unexpected surface of asteroid (101955) bennu |
small, kilometre-sized near-earth asteroids are expected to have young and frequently refreshed surfaces for two reasons: collisional disruptions are frequent in the main asteroid belt where they originate, and thermal or tidal processes act on them once they become near-earth asteroids. here we present early measureme... | craters, boulders and regolith of (101955) bennu indicative of an old and dynamic surface |
generative ai systems across modalities, ranging from text, image, audio, and video, have broad social impacts, but there exists no official standard for means of evaluating those impacts and which impacts should be evaluated. we move toward a standard approach in evaluating a generative ai system for any modality, in ... | evaluating the social impact of generative ai systems in systems and society |
the chicxulub asteroid impact (mexico) and the eruption of the massive deccan volcanic province (india) are two proposed causes of the end-cretaceous mass extinction, which includes the demise of nonavian dinosaurs. despite widespread acceptance of the impact hypothesis, the lack of a high-resolution eruption timeline ... | u-pb geochronology of the deccan traps and relation to the end-cretaceous mass extinction |
the near-earth carbonaceous asteroid 162173 ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. the hayabusa2 spacecraft has obtained global multicolor images of ryugu. geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high bo... | the geomorphology, color, and thermal properties of ryugu: implications for parent-body processes |
recent advancements in artificial intelligence (ai) are fundamentally reshaping computing, with large language models (llms) now effectively being able to generate and interpret source code and natural language instructions. these emergent capabilities have sparked urgent questions in the computing education community ... | the robots are here: navigating the generative ai revolution in computing education |
we present the main improvements and new features in version 2.0 of the open-source c++ library firefly for the interpolation of rational functions. this includes algorithmic improvements, e.g. a hybrid algorithm for dense and sparse rational functions and an algorithm to identify and remove univariate factors. the new... | interpolation of dense and sparse rational functions and other improvements in firefly |
the near-earth asteroid 162173 ryugu, the target of the hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. we report reflectance spectra of ryugu’s surface acquired with the near-infrared spectrometer (nirs3) on hayabusa2, to provide direct measurements of the surface composition and geo... | the surface composition of asteroid 162173 ryugu from hayabusa2 near-infrared spectroscopy |
the pan-starrs data-processing system is responsible for the steps needed to downloaded, archive, and process all images obtained by the pan-starrs telescopes, including real-time detection of transient sources such as supernovae and moving objects including potentially hazardous asteroids. with a nightly data volume o... | the pan-starrs data-processing system |
applying probabilistic methods to infrequent but devastating natural events is intrinsically challenging. for tsunami analyses, a suite of geophysical assessments should be in principle evaluated because of the different causes generating tsunamis (earthquakes, landslides, volcanic activity, meteorological events, and ... | probabilistic tsunami hazard analysis: multiple sources and global applications |
the hayabusa2 spacecraft investigated the small asteroid ryugu, which has a rubble-pile structure. we describe an impact experiment on ryugu using hayabusa2’s small carry-on impactor. the impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central p... | an artificial impact on the asteroid (162173) ryugu formed a crater in the gravity-dominated regime |
early spectral data from the origins, spectral interpretation, resource identification, and security-regolith explorer (osiris-rex) mission reveal evidence for abundant hydrated minerals on the surface of near-earth asteroid (101955) bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spect... | evidence for widespread hydrated minerals on asteroid (101955) bennu |
remote observations of the asteroid (1) ceres from ground- and space-based telescopes have provided its approximate density and shape, leading to a range of models for the interior of ceres, from homogeneous to fully differentiated. a previously missing parameter that can place a strong constraint on the interior of ce... | a partially differentiated interior for (1) ceres deduced from its gravity field and shape |
the origin of earth’s water remains unknown. enstatite chondrite (ec) meteorites have similar isotopic composition to terrestrial rocks and thus may be representative of the material that formed earth. ecs are presumed to be devoid of water because they formed in the inner solar system. earth’s water is therefore gener... | earth’s water may have been inherited from material similar to enstatite chondrite meteorites |
graph neural networks (gnns) extend basic neural networks (nns) by using the graph structures based on the relational inductive bias (homophily assumption). though gnns are believed to outperform nns in real-world tasks, performance advantages of gnns over graph-agnostic nns seem not generally satisfactory. heterophily... | is heterophily a real nightmare for graph neural networks to do node classification? |
establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the formation and degradation mechanisms at work on their surfaces. using images and thermal data from nasa's origins, spectral interpretation, resource identification, and security-regolith explorer (o... | properties of rubble-pile asteroid (101955) bennu from osiris-rex imaging and thermal analysis |
presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the c-type asteroid ryugu by the hayabusa2 mission. on average ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. the abundanc... | on the origin and evolution of the asteroid ryugu: a comprehensive geochemical perspective |
the large synoptic survey telescope (lsst; ivezić et al. 2008) is a large-aperture, wide-field, ground-based survey system that will image the sky in six optical bands from 320 to 1050 nm, uniformly covering approximately 18000 deg2 of the sky over 800 times. the lsst is currently under construction on cerro pachón in ... | the lsst data management system |
primordial black holes (pbhs), formed out of large overdensities in the early universe, are a viable dark matter (dm) candidate over a broad range of masses. ultralight, asteroid-mass pbhs with masses around 1017 g are particularly interesting as current observations allow them to constitute the entire dm density. pbhs... | near future mev telescopes can discover asteroid-mass primordial black hole dark matter |
soil loss by runoff is a severe and continuous ecological problem in koga watershed. deforestation, improper cultivation and uncontrolled grazing have resulted in accelerated soil erosion. information on soil loss is essential to support agricultural productivity and natural resource management. thus, this study was ai... | soil loss estimation using gis and remote sensing techniques: a case of koga watershed, northwestern ethiopia |
the near-earth asteroid (162173) ryugu is thought to be a primitive carbonaceous object that contains hydrated minerals and organic molecules. we report sample collection from ryugu’s surface by the hayabusa2 spacecraft on 21 february 2019. touchdown images and global observations of surface colors are used to investig... | sample collection from asteroid (162173) ryugu by hayabusa2: implications for surface evolution |
the hayabusa2 spacecraft investigated the c-type (carbonaceous) asteroid (162173) ryugu. the mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. we present images of the second touchdown site, finding that ejecta from the impact cra... | pebbles and sand on asteroid (162173) ryugu: in situ observation and particles returned to earth |
microlensing of stars places significant constraints on subplanetary-mass compact objects, including primordial black holes, as dark matter candidates. as the lens' einstein radius in the source plane becomes comparable to the size of the light source, however, source amplification is strongly suppressed, making it cha... | updated constraints on asteroid-mass primordial black holes as dark matter |
light, asteroid-mass primordial black holes, with lifetimes in the range between hundreds to several millions times the age of the universe, are well-motivated candidates for the cosmological dark matter. using archival comptel data, we improve over current constraints on the allowed parameter space of primordial black... | direct detection of hawking radiation from asteroid-mass primordial black holes |
we present a quantitative test of end-cretaceous extinction scenarios and how these would have affected dinosaur habitats. combining climate and ecological modeling tools, we demonstrate a substantial detrimental effect on dinosaur habitats caused by an impact winter scenario triggered by the chicxulub asteroid. we wer... | asteroid impact, not volcanism, caused the end-cretaceous dinosaur extinction |
the hayabusa2 mission journeys to c-type near-earth asteroid (162173) ryugu (1999 ju3) to observe and explore the 900 m-sized object, as well as return samples collected from the surface layer. the haybusa2 spacecraft developed by japan aerospace exploration agency (jaxa) was successfully launched on december 3, 2014 b... | hayabusa2 mission overview |
primordial black holes are under intense scrutiny since the detection of gravitational waves from mergers of solar-mass black holes in 2015. more recently, the development of numerical tools and the precision observational data have rekindled the effort to constrain the black hole abundance in the lower mass range, tha... | primordial black hole constraints with hawking radiation-a review |
rock breakdown due to diurnal thermal cycling has been hypothesized to drive boulder degradation and regolith production on airless bodies. numerous studies have invoked its importance in driving landscape evolution, yet morphological features produced by thermal fracture processes have never been definitively observed... | in situ evidence of thermally induced rock breakdown widespread on bennu's surface |
when the osiris-rex spacecraft pressed its sample collection mechanism into the surface of bennu, it provided a direct test of the poorly understood near-subsurface physical properties of rubble-pile asteroids, which consist of rock fragments at rest in microgravity. here, we find that the forces measured by the spacec... | near-zero cohesion and loose packing of bennu's near subsurface revealed by spacecraft contact |
active fluids comprised of autonomous spinning units injecting energy and angular momentum at the microscopic level represent a promising platform for active materials design. the complexity of the accessible dynamic states is expected to dramatically increase in the case of chiral active units. here, we use shape anis... | reconfigurable emergent patterns in active chiral fluids |
c-type asteroids are among the most pristine objects in the solar system, but little is known about their interior structure and surface properties. telescopic thermal infrared observations have so far been interpreted in terms of a regolith-covered surface with low thermal conductivity and particle sizes in the centim... | low thermal conductivity boulder with high porosity identified on c-type asteroid (162173) ryugu |
to improve the autonomy and intelligence of asteroid landing control, a real-time optimal control approach is proposed using deep neural networks (dnn) to achieve precise and robust soft landings on asteroids with irregular gravitational fields. first, to reduce the time consumption of gravity calculation, dnns are use... | real-time optimal control for irregular asteroid landings using deep neural networks |
light primordial black holes may comprise a dominant fraction of the dark matter in our universe. this paper critically assesses whether planned and future gravitational wave detectors in the ultrahigh-frequency band could constrain the fraction of dark matter composed of subsolar primordial black holes. adopting the s... | hunt for light primordial black hole dark matter with ultrahigh-frequency gravitational waves |
we study the impact of stochastic noise on the generation of primordial black hole (pbh) seeds in ultra-slow-roll (usr) inflation with numerical simulations. we consider the non-linearity of the system by consistently taking into account the noise dependence on the inflaton perturbations, while evolving the perturbatio... | implications of stochastic effects for primordial black hole production in ultra-slow-roll inflation |
empirical standards are natural-language models of a scientific community's expectations for a specific kind of study (e.g. a questionnaire survey). the acm sigsoft paper and peer review quality initiative generated empirical standards for research methods commonly used in software engineering. these living documents, ... | empirical standards for software engineering research |
active asteroids are those that show evidence of ongoing mass loss. we report repeated instances of particle ejection from the surface of (101955) bennu, demonstrating that it is an active asteroid. the ejection events were imaged by the osiris-rex (origins, spectral interpretation, resource identification, and securit... | episodes of particle ejection from the surface of the active asteroid (101955) bennu |
we survey the prospective sensitivities of terrestrial and space-borne atom interferometers to gravitational waves generated by cosmological and astrophysical sources, and to ultralight dark matter. we discuss the backgrounds from gravitational gradient noise in terrestrial detectors, and also binary pulsar and asteroi... | prospective sensitivities of atom interferometers to gravitational waves and ultralight dark matter |
the hayabusa2 spacecraft collected samples from the surface of the carbonaceous near-earth asteroid (162173) ryugu and brought them to earth. the samples were expected to contain organic molecules, which record processes that occurred in the early solar system. we analyzed organic molecules extracted from the ryugu sur... | soluble organic molecules in samples of the carbonaceous asteroid (162173) ryugu |
we revise primordial black holes (pbhs) production in the axion-curvaton model, in light of recent developments in the computation of their abundance accounting for non-gaussianities (ngs) in the curvature perturbation up to all orders. we find that ngs intrinsically generated in such scenarios have a relevant impact o... | primordial black holes in the curvaton model: possible connections to pulsar timing arrays and dark matter |
the top-shaped morphology characteristic of asteroid (101955) bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior t... | the dynamic geophysical environment of (101955) bennu based on osiris-rex measurements |
in 2018, the japanese spacecraft hayabusa2, arrived at the small asteroid ryugu. the surface of this c-type asteroid is covered with numerous boulders whose size and shape distributions are investigated in this study. using a few hundred optical navigation camera (onc) images with a pixel scale of approximately 0.65 m,... | boulder size and shape distributions on asteroid ryugu |
orbital elements are presented for 70 of the 95 meteor showers considered ;established; by the international astronomical union. from 2010 october 21 until 2013 march 31, the low-light-video based cameras for allsky meteor surveillance project (cams) measured a total of 110,367 meteoroid trajectories and pre-atmospheri... | the established meteor showers as observed by cams |
in a reduction sequence of a graph, vertices are successively identified until the graph has one vertex. at each step, when identifying $u$ and $v$, each edge incident to exactly one of $u$ and $v$ is coloured red. bonnet, kim, thomassé and watrigant [j. acm 2022] defined the twin-width of a graph $g$ to be the minimum... | reduced bandwidth: a qualitative strengthening of twin-width in minor-closed classes (and beyond) |
aims: the radial velocity spectrometer (rvs) on board the esa satellite mission gaia has no calibration device. therefore, the radial velocity zero point needs to be calibrated with stars that are proved to be stable at a level of 300 m s-1 during the gaia observations.methods: we compiled a dataset of ~71 000 radial v... | gaia data release 2. the catalogue of radial velocity standard stars |
we give a deterministic $m^{1+o(1)}$ time algorithm that computes exact maximum flows and minimum-cost flows on directed graphs with $m$ edges and polynomially bounded integral demands, costs, and capacities. as a consequence, we obtain the first running time improvement for deterministic algorithms that compute maximu... | a deterministic almost-linear time algorithm for minimum-cost flow |
asteroid shapes and hydration levels can serve as tracers of their history and origin. for instance, the asteroids (162173) ryugu and (101955) bennu have an oblate spheroidal shape with a pronounced equator, but contain different surface hydration levels. here we show, through numerical simulations of large asteroid di... | collisional formation of top-shaped asteroids and implications for the origins of ryugu and bennu |
volatile and organic-rich c-type asteroids may have been one of the main sources of earth's water. our best insight into their chemistry is currently provided by carbonaceous chondritic meteorites, but the meteorite record is biased: only the strongest types survive atmospheric entry and are then modified by interactio... | a pristine record of outer solar system materials from asteroid ryugu's returned sample |
we investigate the generation of primordial black holes (pbhs) with the aid of gravitationally increased friction mechanism originated from the nonminimal field derivative coupling (nmdc) to gravity framework, with the quartic potential. applying the coupling parameter as a two-parted function of inflaton field and fin... | primordial black holes in nonminimal derivative coupling inflation with quartic potential and reheating consideration |
traditional online continual learning (ocl) research has primarily focused on mitigating catastrophic forgetting with fixed and limited storage allocation throughout an agent's lifetime. however, a broad range of real-world applications are primarily constrained by computational costs rather than storage limitations. i... | online continual learning without the storage constraint |
sugars are essential molecules for all terrestrial biota working in many biological processes. ribose is particularly essential as a building block of rna, which could have both stored information and catalyzed reactions in primitive life on earth. meteorites contain a number of organic compounds including key building... | extraterrestrial ribose and other sugars in primitive meteorites |
autonomous spacecraft relative navigation technology has been planned for and applied to many famous space missions. the development of on-board electronics systems has enabled the use of vision-based and lidar-based methods to achieve better performances. meanwhile, deep learning has reached great success in different... | deep learning-based spacecraft relative navigation methods: a survey |
we present the discovery of ps18kh, a tidal disruption event discovered at the center of sdss j075654.53+341543.6 (d ≃ 322 mpc) by the pan-starrs survey for transients. our data set includes pre-discovery survey data from pan-starrs, the all-sky automated survey for supernovae, and the asteroid terrestrial-impact last ... | ps18kh: a new tidal disruption event with a non-axisymmetric accretion disk |
carbonaceous asteroids, such as (101955) bennu, preserve material from the early solar system, including volatile compounds and organic molecules. we report spacecraft imaging and spectral data collected during and after retrieval of a sample from bennu’s surface. the sampling event mobilized rocks and dust into a debr... | spacecraft sample collection and subsurface excavation of asteroid (101955) bennu |
the near-earth asteroid (162173) ryugu is a 900-m-diameter dark object expected to contain primordial material from the solar nebula. the mobile asteroid surface scout (mascot) landed on ryugu’s surface on 3 october 2018. we present images from the mascot camera (mascam) taken during the descent and while on the surfac... | images from the surface of asteroid ryugu show rocks similar to carbonaceous chondrite meteorites |
the zwicky transient facility is a large optical survey in multiple filters producing hundreds of thousands of transient alerts per night. we describe here various machine learning (ml) implementations and plans to make the maximal use of the large data set by taking advantage of the temporal nature of the data, and fu... | machine learning for the zwicky transient facility |
the lack of pyrimidine diversity in meteorites remains a mystery since prebiotic chemical models and laboratory experiments have predicted that these compounds can also be produced from chemical precursors found in meteorites. here we report the detection of nucleobases in three carbonaceous meteorites using state-of-t... | identifying the wide diversity of extraterrestrial purine and pyrimidine nucleobases in carbonaceous meteorites |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.