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宇宙工学・惑星科学・宇宙物理の最新プレプリント。

astro-ph.SRastro-ph.EPastro-ph.GA

Coevolution of Dust Growth and Gravitational Instability in Massive Protostellar Disks

Ryota Yamamuro, Ryoki Matsukoba, Kei E. I. Tanaka, Eduard I. Vorobyov

Massive protostellar disks are expected to sustain high accretion rates through gravitational instability, while dust growth may modify their opacity, cooling efficiency, and stability. Conversely, the time-dependent and nonaxisymmetric structures produced by gravitational instability may regulate the local conditions for dust growth. However, the coupled evolution of dust growth and gravitational instability in massive protostellar disks has not yet been explored self-consistently. We present t…

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astro-ph.SRphysics.space-phstat.AP

Real-Time 24-hour Ahead Forecasting of Solar Energetic Particle Events with SEPNET-PRISM-R

Yian Yu, Yang Chen, Lulu Zhao, Kathryn Whitman, Ward Manchester, Tamas Gombosi

Solar energetic particle (SEP) events, operationally defined as proton flux exceeding 10 pfu in the >10 MeV channel, threaten spacecraft systems, astronaut safety, and high latitude aviation, yet continuous real-time forecasting with adequate lead time remains difficult. We present SEPNET-PRISM-R, a near-real-time system that issues hourly, 24 hour ahead probabilistic SEP forecasts. The model integrates multimodal solar data - including active region patches, flare features, coronal mass ejectio…

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astro-ph.SR

The Effect of Field Line Tracing Height on Wang-Sheeley-Arge Solar Wind Predictions at Earth

Satabdwa Majumdar, Martin A. Reiss, Pete Riley, Charles N. Arge

(Abridged abstract): A key component of the widely used Wang-Sheeley-Arge model is the tracing of magnetic field lines in the solar corona, as that largely determines the modeled open/closed field regions and in turn the predicted large-scale solar wind structure. We demonstrate that by slightly raising the height from which magnetic field lines are traced from the photosphere (R$_{su}$), we can improve the prediction of solar wind high-speed enhancements (HSEs). We find a higher R$_{su}$ produc…

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astro-ph.SR

Orbital Parameters for 65 Wide Binary Systems: no evidence for gravitational anomaly at low acceleration

L. Pasquini, R. Saglia, F. Patat, L. Berni, D. Bossini, L. Magrini, H. -G. Ludwig, M. T. Murphy et al.

We use a Monte Carlo analysis to study whether wide binaries can be represented by bound Newtonian orbits, and, if this is the case, whether the distribution of the orbital parameters agrees with expectations. The potential orbits are classified according to the $χ^2$ probability of representing star coordinates, parallaxes, velocity components and masses. We apply this analysis to 44 systems previously published, to which we add 26 wide binaries, consisting of twin low-mass (M) stars. We find o…

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astro-ph.HE

Hidden engines in tidal disruption events: multimessenger signatures in a lepto-hadronic framework

D. Kantzas, D. A. Langis, I. Liodakis, A. Paggi

Tidal disruption events (TDEs) provide a unique laboratory for studying transient accretion, outflows, particle acceleration, and the possible connection between stellar disruptions and high-energy neutrinos. Motivated by recent candidate TDE-neutrino associations and by the forthcoming sensitivity of multimessenger facilities, we investigate under which physical conditions TDEs can be detected in MeV, GeV, and TeV gamma rays, and in high-energy neutrinos. We develop a lepto-hadronic emission fr…

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gr-qcastro-ph.HE

On the Stability of Tolman Oppenheimer Volkoff Fireholes

Pablo Laguna, Octavio Guerrero, Kostas Kokkotas

We investigate the radial stability of singular Tolman--Oppenheimer--Volkoff fireholes with a radiation equation of state. These configurations contain a naked, negative point-mass singularity surrounded by a positive-density fluid, whose mass profile develops a Schwarzschild-like plateau before approaching an extended, self-similar atmosphere. Using the Prüfer phase method to identify the fundamental radial mode, we consider two outer boundary conditions: vanishing Lagrangian pressure perturbat…

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astro-ph.SRphysics.space-ph

Detection and Statistics of large-scale Sector Boundary Crossings in the Solar Wind: The SBCross Catalog

Stephan G. Heinemann, Manuela Temmer, Mathew Owens, Emilia Kilpua, Charles Farrugia, Daniel Price

Heliospheric sector boundary crossings (SBCs), composed of the Heliospheric Current Sheet (HCS), Heliospheric Plasma Sheet (HPS), and surrounding plasma halo, represent fundamental structures in the solar wind that influence interplanetary dynamics and space weather. We present the \textsc{SBCross} catalog, an automated, publicly available database containing 1,076 SBC events derived from in-situ observations spanning more than 30 years (1995--2026), covering Solar Cycles 23 and 24 alongside the…

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astro-ph.IMcs.LG

SIGNN++: Robust Graph Neural Star Identification on Earth

Jeongbin Sohn, Jina Lee, Max Yen, Dowan Gwon, Jeahn Han, Floyd Hepburn-Dickins, Brian Coltin, Ryan Soussan et al.

We present SIGNN++, a learning-based star identification (SID) framework for celestial navigation in GNSS-denied nighttime environments. Although researchers have developed learning-based SID methods to improve robustness to observation noise, prior evaluations have focused mainly on synthetic or non-terrestrial environments, leaving their reliability under real terrestrial conditions unclear. To address these limitations, SIGNN++ extends SIGNN, a graph neural network-based SID method, with thre…

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astro-ph.SRphysics.space-ph

Deriving Interplanetary Sector Boundary Crossings using Potential Field Source Surface Modeling

Stephan G. Heinemann, Manuela Temmer, Jens Pomoell, Mathew Owens, Emilia Kilpua, Matti ala-Lahti, Andreas Wagner

The Heliospheric Current Sheet (HCS) and associated interplanetary sector boundaries fundamentally structure the solar wind environment, modulating coronal mass ejection (CME) evolution and solar energetic particle transport. In this study, we evaluate the capability of a static Potential Field Source Surface (PFSS; $R_{ss}=2.5R_\odot$) coronal model to directly map interplanetary sector boundary crossings from the Sun to 1 au without dynamic heliospheric propagation models. We compare ballistic…

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astro-ph.EPastro-ph.IM

The T-matrix method for modeling the optical properties of grains in exoplanetary atmospheres

Giambattista Aresu, Giovanni La Mura, Giacomo Mulas, Cesare Cecchi-Pestellini, Maria Antonia Iatì, Shadi Rezaei, Antonino Petralia, Daniele Locci et al.

Observations of exoplanetary atmospheres have revealed a rather complex co-existence between the gaseous and condensed phases, ranging from atmospheres apparently covered in clouds to clear ones, across a myriad of intermediate regimes. The interaction between solids and stellar radiation is of fundamental importance when forward or retrieval models are compared to observations. The simplest approach is to assume spherical particles, whose scattering and absorption properties are readily compute…

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astro-ph.HEastro-ph.GA

Pulsar J1909+0749 and Supernova Remnant G42.1-0.2: A case of a pulsar that has exited the shell of its associated supernova remnant

R. Dokara, M. Kramer, A. Brunthaler, M. J. Keith, B. W. Stappers

(Abridged) The ATNF pulsar catalogue features only 63 pulsars that are possibly associated with a supernova remnant (SNR). Even rarer is the scenario in which the pulsar has escaped the physical extent of its corresponding SNR. We aim to identify the serendipitously discovered shell-type object G42.1-0.2 as a SNR. The known pulsar (PSR) J1909+0749 lies well outside the shell of SNR G42.1-0.2, but it has a cometary tail pointing towards the centre of the SNR; we propose that the SNR and the pulsa…

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astro-ph.HEhep-ph

Constraints on Dark Matter Annihilation from Starlight-Induced Inverse Compton Emission in Omega Centauri

Guan-Sen Wang, Xu Pan, Lei Feng

The search for the particle identity of dark matter (DM) remains one of the foremost challenges in modern physics. In this work, we derive new constraints on the DM annihilation cross section $\langleσv\rangle$ by considering the inverse Compton (IC) scattering of DM annihilation injected $e^+e^-$ off the starlight radiation field in Omega Centauri. As a likely remnant core of a dwarf galaxy, Omega Centauri provides a dense stellar environment that enhances the predict IC signal. Using multi-wav…

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astro-ph.HEastro-ph.SR

On the superbursts as photodisintegrators of ashes from the rp-process -- Numerical simulations of superbursts with MESA II

M. Nava-Callejas, S. Goriely, N. Chamel

Context: Superbursts are energetic explosions in the crusts of neutron stars in Low-Mass X-ray Binaries (LMXBs). At temperatures above 4 GK, photodisintegration of heavy rp-process ashes may play a major role alongside $^{12}$C fusion. Aims: We investigate how photodisintegration of rp-process ashes affects superburst properties and the initial $^{12}$C abundance required for ignition. Methods: We simulate superbursts with MESA v.24.08.1. Besides the canonical fuel of $20\%$ $^{12}$C and $80\%$…

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astro-ph.HEphysics.plasm-ph

Rapid Variability of Radiative Signatures from Driven Relativistic Reconnection

Clarissa Mora, Fabio Bacchini, Camille Granier, Daniel Groselj

Rapid variability in energetic flares is a distinctive feature of high-energy emission from many magnetically dominated astrophysical sources. We investigate the radiative variability of driven relativistic magnetic reconnection using Particle-in-Cell simulations of strongly magnetized flux tubes pushed to merge at driving speed $v_{\rm push}$. This setup captures the onset of reconnection and provides a controlled model for single reconnection-driven flares near compact objects, where magnetic…

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nucl-thastro-ph.HEcond-mat.str-el

Direct Urca process facilitated by non-Fermi-liquid quantum criticality

Hao-Fu Zhu, Guo-Zhu Liu

Conventional Fermi-liquid theories of dense nuclear matter predict that the direct Urca process requires a proton fraction above a threshold of $Y_p \approx 0.11$--$0.15$, which is rarely reached in low-mass neutron stars. Here we show that this stringent kinematic constraint is drastically relaxed by the non-Fermi liquid behavior arising from superfluid and superconducting quantum criticality in neutron stars. In the non-Fermi-liquid regimes, nucleons have a smooth momentum occupation without a…

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astro-ph.GAastro-ph.CO

Kinematically isolating intracluster light in AS1063: a distinct stellar population tracing the dark matter core

Callum Bellhouse, Steven Bamford, Nina Hatch, Tutku Kolcu, Johan Richard

We present a technique using integral-field spectroscopy to kinematically isolate intracluster light (ICL) from the brightest cluster galaxy (BCG), enabling insights into their contrasting stellar populations and the inner dark matter halo profile. Applying this technique to MUSE data of Abell S1063, we find that both components are old (~9 Gyr), but the ICL is more metal-poor than the BCG, implying distinct progenitor pathways. Within 100 kpc, the ICL comprises 55 per cent of the BCG+ICL stella…

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astro-ph.IM

An improvement to the spatial discretisation in the Astrophysical Weighted Particle Hydrodynamics method

Alex Massaro Achá, Isaac Alonso Asensio, Claudio Dalla Vecchia

The discretisation of space in the Astrophysical Weighted Particle Hydrodynamics method is attained through a partition-of-unity-based cubature rule. The node (particle) weights in such rules must in general be obtained using approximations, for which only one has been thus far proposed in the literature. In this work, new approximations for these weights are proposed, their properties are studied, and their impact on the accuracy of the cubature rule and the overall method is assessed. Approxim…

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astro-ph.SRastro-ph.EPastro-ph.GAastro-ph.IM

Phakoseismology: Asteroseismology of gravitationally microlensed stars

Marcus L. Marcussen, Mikkel N. Lund

Asteroseismology relies on disk-integrated photometry or radial velocities, in which geometric cancellation suppresses modes of high spherical degree ($l\geq4$). Observations are thus limited to deeply penetrating, low-degree modes, leaving the outer envelope inaccessible. We investigate whether a high-magnification microlensing event can temporarily lift this limitation by differentially magnifying the surface of an oscillating source star. We modelled the visibility of solar-like oscillations…

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astro-ph.GA

Understanding the formation of alpha-Fe bimodality in the Milky Way using constrained cosmological simulations of the Local Group

Anna Genina, Ewoud Wempe, Amina Helmi, Hanneke C. Woudenberg, Simon D. M. White, Robert J. J. Grand, Ruediger Pakmor, Guilhem Lavaux et al.

We use a novel suite of constrained cosmological simulations of the Local Group to investigate the formation of alpha--Fe bimodalities in stellar discs of Milky Way analogues. In agreement with past studies using the Auriga model, we show that in our simulations the high-alpha sequence forms in a merger-induced starburst, which further quenches star formation, allowing the new stellar populations to form at low [alpha/Fe]. Producing a bimodality that is prominent at large radii, with a significa…

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astro-ph.GA

VVV CL001: A strong candidate for the most ancient star cluster in the Galaxy

J. Olivares Carvajal, Á. Valenzuela Navarro, C. Salvo-Guajardo, C. Ordenes-Huanca, B. Acosta-Tripailao, C. Quezada, F. Gran, M. Zoccali et al.

Finding the oldest globular cluster of the Galaxy is important to constrain a lower limit on the age of the Galaxy and the Universe. VVV CL001 ([l,b]= [5.26,0.77]) is perhaps the most metal-poor ([Fe/H]~-2.2 dex) globular cluster in the Galactic bulge and a promising candidate to be the oldest globular cluster in the entire Milky Way. Due to its recent discovery and high extinction, its physical parameters, especially the distance and age, remain highly uncertain, yet they are essential to defin…

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astro-ph.GAastro-ph.SR

Constraining Solid HNCO and Its Environment in Open JWST Data with Laboratory Spectra

Ruslan Nakibov, Varvara Karteyeva, Katerina Borshcheva, Igor Petrashkevich, Mikhail Medvedev, Anton Vasyunin

The presence of HNCO in the gaseous phase is well known for the interstellar medium, but the molecule is not detected yet in the solid phase. We report the first laboratory-confirmed identification of solid HNCO at 2260 cm$^{-1}$ in open JWST data using laboratory infrared spectra. For that, we grew binary mixtures of HNCO with main constituents of interstellar ice using ISEAge setup at 10 K: HNCO:H$_2$O = 1:10, HNCO:CO = 1:10, HNCO:CO$_2$ = 1:10, HNCO:CH$_3$OH~=~1:10. We present transmission in…

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astro-ph.HEastro-ph.SR

The environments of type Ibn supernovae: evidence for a strong Wolf-Rayet star component

Timo Kravtsov, Hanindyo Kuncarayakti, Joseph P. Anderson

Characterisation of progenitor stars of supernovae (SNe) poses several challenges. Direct observations of progenitors are based on serendipitious archival observations and are only possible for nearby events. Indirect methods include inferring nickel mass from the light curves or oxygen masses from the SN's nebular phase, both of which are tools to constrain the progenitor's initial mass. Alternatively, environments of SNe have been used as a proxy for the progenitor's age and metallicity. The p…

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physics.space-phastro-ph.SReess.SP

A Catalog of Dispersive Ionospheric and Plasmaspheric Arcs from Cislunar and Lunar-surface GNSS Radio Occultations

Francesco Fiorina, Alex Minetto, Rebecca Ghidoni, Marco Guerra, Claudio Cesaroni, Luca Spogli, Andrea Nardin, Fabio Dovis et al.

This dataset is a catalog of 263 dispersive arcs induced by ionospheric and plasmaspheric occultation observed in GNSS signals recorded by the Lunar GNSS Receiver Experiment (LuGRE) payload during Blue Ghost Mission 1 (BGM1), in cislunar space and on the lunar surface. Occultation arcs are identified and classified as ingress, egress or tangent by combining independently GPS and Galileo dual-frequency observables and computing the rate of the total electron content (ROT) and ROT index (ROTI), an…

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astro-ph.HE

A bright X-ray flaring event from the intermediate supergiant fast X-ray transient IGR J00370+6122 observed with NuSTAR

L. Ducci, M. M. Serim, P. Romano, E. Bozzo, L. Ji, C. Malacaria

We present an analysis of a long NuSTAR observation of the intermediate supergiant fast X-ray transient (SFXT) IGR J00370+6122, obtained around the peak of its orbital modulation. The observation has a net exposure ~93 ks. During the observation, the source displayed a bright flaring event that was resolved into numerous short flares with durations of 10-1000 s. The 3-70 keV luminosity spanned a dynamic range of ~200, from ~1E34 to ~1.8E36 erg/s; the maximum was reached for only ~40 s in total.…

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astro-ph.GA

Single-Parameter Exponential Model Outperforms Standard Dark Matter and Modified Newtonian Frameworks in Predicting Galactic Rotation Curves

Mohammed Guhdar

The functional forms of galactic rotation curves provide a fundamental test for models of gravity and dark matter. In this work, we conduct a rigorous statistical comparison of five distinct models against the complete sample of 175 galaxies from the SPARC database. The models under consideration are: (1) a one-parameter empirical law, physically constrained by each galaxy's measured flat disc rotation velocity ($V_{\text{flat}}$); (2) a classical two-parameter Freeman disk; (3) a three-paramete…

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astro-ph.GA

The chemical evolution of the LMC from APOGEE abundances: a hybrid two-infall OMEGA+ analysis

Erik Gasteiger, Viola Hegedűs, Szabolcs Mészáros

The Large Magellanic Cloud (LMC) provides resolved stellar abundances and star-formation histories that can be used together to test models of dwarf-galaxy chemical evolution. We investigated if the non-monotonic APOGEE $[\mathrm{Mg}/\mathrm{Fe}]$-$[\mathrm{Fe}/\mathrm{H}]$ sequence can be explained by a hybrid history that combines a second gas-infall episode with a temporary increase in star-formation efficiency (SFE). We selected 4933 LMC red-giant-branch stars from APOGEE-2 DR17. We fitted a…

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astro-ph.HEastro-ph.SR

What Shapes the Ultraviolet Spectra of Type Ia Supernovae?

Snehasish Bhattacharjee, Yen-Chen Pan, Anirban Dutta, Shubham Gupta, Chia-Yu Cheng, Charles D. Kilpatrick, Matthew R. Siebert

Ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) exhibit significant diversity, but their physical origin remains poorly understood. We investigate UV spectra of SNe Ia observed with the Swift UltraViolet and Optical Telescope. Our expanded pre-maximum sample probes dependencies on decline rate, ejecta properties, and host environment. We recover the correlation between UV flux and decline rate near maximum in the near-UV (NUV), and find correlations at pre-maximum phases in both the…

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astro-ph.GA

Probing the Optical/UV Continuum Variability of Active Galactic Nuclei with the Damped Random Walk Model

Xiang-Wei Ning, Wen-Jie Hu, Zi-Han Yuan, Yi Tang, Yan-Song Ma, Yu-Meng Gua, Le-Yi Huang, Wei-Hao Bian et al.

Optical/UV continuum variability over baselines of up to 20 yr is investigated using the damped random walk (DRW) model for 1214 active galactic nuclei (AGNs) compiled from Y. Shen et al. and C. J. Burke et al. Among these, 115 AGNs with reliable DRW fitting and unbiased DRW parameters (timescale $τ_{2500}$ and amplitude $σ_{2500}$ at the rest-frame 2500~Å) are used to examine the relations between the variability and the accretion properties. We found a significant correlation of $τ_{2500}$ wit…

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astro-ph.EP

When the core ate the atmosphere

Vera Sparrman, Anders Johansen

The initial volatile element inventories in a planet's atmosphere, mantle, and core are established by delivery and transport during planetary growth. Conversely, the volatile abundances of Earth's planetary reservoirs record its accretion pathway. We model here volatile transport during planet formation for two different delivery scenarios, via pebble and planetesimal accretion, to predict the volatile inventories of proto-Earth at the end of its main accretion phase. We find that the distribut…

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astro-ph.GA

Cosmic-ray melt windows in interstellar ice make a four-carbon ketose but not the sugar pattern of G+0.693-0.027

S. Saito, M. Yajima, T. Kenmotsu, M. Wada, K. Kobayashi, H. Nakamura, G. Chiaki

Erythrulose (ERU), a four-carbon (C4) ketose, is reported towards the Galactic-centre cloud G+0.693-0.027 at a column density comparable to that of glycolaldehyde (GA), while the three-carbon (C3) sugars are not detected. We test whether melt windows opened in interstellar ice by cosmic-ray heavy ions can reproduce this pattern, with each rate fixed to a published value where available. A track model for eleven cosmic-ray nuclei determines the rate and duration of the liquid windows and the ener…

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