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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.GA

Concerns regarding recurrent fluorescence's impact on smaller diffuse ISM aromatics

Daniel Majaess, Cercis Morera-Boado, Tina A. Harriott, Cherif F. Matta

Recent research implied that recurrent fluorescence (RF) could bolster smaller aromatics against fragmentation in the diffuse ISM, yet that hypothesis is contested by timescales for unrelenting dissociative recombination (electrons), and unceasing dissociating photons. Specifically, neutral cyanonaphthalene can sustain $13.6$ eV photoionization, and the ensuing cation's excess energy is channeled through intramolecular vibrational redistribution (IVR), with RF providing the radiative stabilizati…

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astro-ph.GA

The Stellar Population of NGC 346 in the Small Magellanic Cloud with JWST

J. Jaspers, P. Kavanagh, G. De Marchi, C. Nally, O. Jones, N. Habel, P. Zeidler, M. Meixner et al.

NGC 346 is a massive star-forming region located at a distance of $\sim$62 kpc, in the Small Magellanic Cloud (SMC). Due to its low metallicity (Z $\sim$1/5 Z$_{\odot}$), it is an ideal environment to study star formation and stellar population analogues to those at Cosmic Noon. In this work, we produce a combined JWST NIRCam and MIRI photometric catalogue of NGC 346. We characterise different stellar populations in the region: the upper main sequence (UMS), red giant branch (RGB), and red clump…

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astro-ph.SR

3D simulations of magnetospheric accretion in T Tauri stars: I. Disk truncation, stellar torques, and application to observations

George Pantolmos, Claudio Zanni, Jérôme Bouvier

Young stars accrete material from their circumstellar disk through their magnetosphere while still contracting, two processes that impact their rotational evolution. We investigate stable and unstable accretion regimes (due to the interchange instability) and examine the associated stellar torques to assess the spin evolution of young stars. We perform 3D MHD simulations of disk accretion onto an inclined stellar dipole. We run 21 simulations with varying stellar stellar rotation rates, dipole f…

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astro-ph.EP

Triggered Fragmentation in Self-Gravitating Protoplanetary discs: Cooling, Mass Movement and Instability

Pratishtha Rawat, Farzana Meru, Rebecca Nealon

Previous three-dimensional hydrodynamical simulations of gravitationally unstable discs have shown that the formation of a single fragment can trigger the formation of subsequent fragments. This behaviour was attributed to changes in the surface mass density caused by the interaction between the first fragment and the disc material. This study reanalyses those simulations to see if the surface mass density was the sole driver. Our results reveal that both surface mass density and sound speed can…

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astro-ph.IMastro-ph.EP

Accurately simulating gain and clock-induced charge production in the EMCCD gain register

Kevin J. Ludwick

An electron-multiplying charge-coupled device (EMCCD) is capable of precise detections in low-signal environments, able to detect a single photon through electron multiplication. It has many applications, such as faint-target astronomy, quantum optics, molecule tracing, and others, and it will be used for faint companion detection in the Roman Telescope's coronagraph instrument. In an EMCCD, photons hit the pixels, and photo-electrons are created; these are multiplied via impact ionization as th…

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astro-ph.IM

Simulation tools for realistic high-order wavefront correction with the Roman Coronagraph

A. Lau, A. J. Riggs, S. F. Redmond, E. Cady, J. Krist, I. Laginja, D. Sirbu, L. Delaye et al.

The Roman Space Telescope Coronagraph Instrument (Roman CGI) will demonstrate high-contrast imaging from space using coronagraphic masks, deformable mirrors, and high-order wavefront sensing and control (HOWFSC). After the baseline technology demonstration, the Roman Coronagraph Community Participation Program (CPP) will pursue science and engineering studies that require realistic predictions of instrument behaviour, observing efficiency, and wavefront control performance. This paper describes…

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astro-ph.HE

The high entropy of the UHECR arrival direction distribution favors a light composition

Nimrod Strasman, Eli Waxman

We analyze the constraints on the composition of ultra-high-energy cosmic rays (UHECRs), and on the density and distribution of their sources, that may be inferred from their arrival-direction distribution, using a novel semi-analytical description of the propagation energy loss of atomic nuclei ($A>4$) with energy $>2\times10^{19}~\text{eV}$, that allows generating UHECR arrival maps faster than by using detailed propagation simulations and yields insights to the impact of propagation energy lo…

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nucl-exastro-ph.HEastro-ph.SRnucl-th

Revised $^{45}$V($p,γ$)$^{46}$Cr reaction rate and its impact on the production of $^{44}$Ti in core-collapse supernovae

R. S. Sidhu, Y. Luo, C. Sarma, M. Wiescher, X. Xu

The thermonuclear $^{45}$V($p,γ$)$^{46}$Cr reaction is the primary leakage pathway from the $^{44}$Ti--$^{45}$V quasi-equilibrium cluster during $α$-rich freeze-out in core-collapse supernovae (CCSN), governing the final abundance of the $γ$-ray-emitting isotope $^{44}$Ti. A recent high-resolution $γ$-ray study [C. Cousins \textit{et al.}, Phys. Rev. Lett. 136, 252701 (2026)] identified ten previously unknown low-spin proton-unbound states in $^{46}$Cr, enabling the first experimentally constrai…

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astro-ph.IM

The Roman Coronagraph Community Participation Program: Using the Zernike wavefront sensor for a full characterisation of the Roman Space Telescope and the Coronagraph Instrument

Arthur Vigan, Alexis Bidot, Vincent Chambouleyron, Garreth Ruane, Laurent Pueyo, Mamadou N'Diaye, Kjetil Dohlen

The Roman Space Telescope Coronagraph Instrument (CGI) will demonstrate a series of technologies and techniques to enable the direct detection of reflected-light planets with space-based observatories. Among the several available observing modes and coronagraphic devices embarked in CGI, there is the transmissive dual-path Zernike wavefront sensor (ZWFS) that could be used to directly measure optical aberrations in the system. The dual-path ZWFS is currently unsupported, but in this work we advo…

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astro-ph.HE

The initial evolution of SN 2011dh: The importance of inhomogeneities

Claes-Ingvar Bjornsson

SN 2011dh is rather unique in that it offered detailed observations of the initial phase in the radio as well as optical regimes. This makes possible a comparison between models used to deduce properties of the outer envelope of the supernova ejecta. It is shown that a consistent description suggests the forward shock to have started in the piston phase with constant velocity, and only later, around 50 days, transitioned to the standard model, which is independent of initial conditions. In addit…

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astro-ph.GAastro-ph.CO

eROSITA cosmology with galaxy groups: hot gas budget out to the virial radius

H. Khalil, A. Finoguenov, D. Eckert, R. Seppi, E. Tempel, L. Lovisari, F. Gastaldello

Non-gravitational processes that expel hot gas beyond the virial regions of groups and clusters of galaxies, known collectively as baryonic feedback, play a key role in reshaping the matter distribution of the Universe on Mpc scales. We use eROSITA observations of a complete sample of 25 galaxy groups selected from the first public release of the eROSITA-DE data (eRASS1) and identified with the Two Micron Redshift Survey optical group catalogue (2MRS). We extract and fit surface brightness (SBx)…

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astro-ph.SRastro-ph.EP

A Catalog of Homogeneously Derived Stellar Parameters for Spectroscopic Survey Stars

Stefan Y. Stefanov, Evelina Zaharieva, Djemma Ruseva, Milen Minev, Denitza Stoeva, Volker Perdelwitz, Lev Tal-Or, Jerusalem T. Teklu et al.

Uniformly derived stellar parameters are vital for exoplanet demographic studies because they directly influence the inferred planetary masses, radii, and bulk densities. This study presents a new homogeneous catalog of physical stellar parameters for 5533 single stars observed by the HARPS, HIRES, and CARMENES radial-velocity (RV) surveys. Stellar parameters are determined using a Bayesian framework with two independent sets of stellar evolutionary models: MIST and PARSEC, using published spect…

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physics.hist-phastro-ph.EP

Astrobiology and the Transformation of Scientific Epistemology

Kristina Šekrst

Astrobiology occupies an unusual position within the philosophy of science. Confronted with the n = 1 problem - having only a single example of life to study - it attempts to investigate life beyond Earth while relying entirely on Earth's biosphere as its reference point, a constraint that creates unique epistemic challenges. Unlike traditional sciences with clear predictive frameworks, astrobiology operates as what we might call a transient science: a discipline functioning without foundational…

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astro-ph.EP

Radar observations of Europa in 2011-2024: New insights into radar scattering properties

Tunhui Xie, Jean-Luc Margot, Sebastiano Padovan, Frank Ghigo, Will Armentrout, Joseph S. Jao, Jon D. Giorgini, Joseph Lazio et al.

Three of Jupiter's Galilean satellites - Europa, Ganymede, and Callisto - are of particular scientific interest due to their icy shells and suspected subsurface oceans. However, the radar properties of the icy satellites have not been measured since observations in 1987-1991. Because radio waves can penetrate pure ice to considerable depths, radar observations provide a powerful means of characterizing the subsurface properties of the icy shells of these satellites, offering key insights into pl…

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hep-phastro-ph.COastro-ph.HE

An axion constraint from the diffuse supernova neutrino background indicated by Super-Kamiokande

Kanji Mori, Tomoya Takiwaki, Kazunori Kohri, Masamitsu Mori

Recently, the Super-Kamiokande Collaboration reported an indication of the diffuse supernova neutrino background (DSNB) with a statistical significance of $2.6σ$. Motivated by this possible discovery, we investigate the impact of axion cooling on the DSNB flux on the basis of long-term neutrino-radiation hydrodynamic simulations. We compare the observed flux and our models and obtain a $1σ$ upper limit $|g_{ap}|<1.3\times10^{-9}$ on the axion-proton coupling constant, which is comparable to the…

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astro-ph.GA

$R_{\rm e}$, or not $R_{\rm e}$: Developing $R_5\equiv R_{-2}$ as a scale radius for galaxy sizes, masses, and mass-to-light ratios

Alister W. Graham

The effective half-light radius $R_{\rm e}$ marks an arbitrary 50-per-cent light boundary, and scaling relations involving such effective radii and their associated surface brightnesses, $μ_{\rm e}$, depend systematically on the adopted percentage. Here, a gradient-defined scale, $R_5\equiv R_{-2}$, is developed as an alternative. It is the projected radius where the logarithmic slope of the intensity profile is equal to $-2$, corresponding to a slope of the surface-brightness profile of $5.00\,…

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astro-ph.GA

$R_{\rm e}$, or not $R_{\rm e}$: Developing $R_5\equiv R_{-2}$ as a scale radius for galaxy sizes, masses, and mass-to-light ratios

Alister W. Graham

The effective half-light radius $R_{\rm e}$ marks an arbitrary 50-per-cent light boundary, and scaling relations involving such {\it effective} radii and their associated surface brightnesses, $μ_{\rm e}$, systematically (and undesirably) vary as the percentage changes. Here, the projected radius $R_5\equiv R_{-2}$, where the logarithmic slope of the surface-brightness and intensity profile equals $5.00\,\text{mag\,dex}^{-1}$ and $-2$, respectively, and where the luminosity contributed per logar…

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cs.LGastro-ph.IMphysics.data-an

Safe Domain Adaptation for Physics: Overcoming Nuisances, Label Shifts, and Simulation Priors

Ivan Kharuk

Domain adaptation is widely used to make neural networks trained on simulations applicable to experimental data. Its premise is that the two domains differ only in nuisances, and that the quantity of interest is distributed identically in both. In physics neither assumption holds: simulations can be wrong about the physics, and the distribution of the target quantity - an energy spectrum, a redshift distribution - is often the measurement itself. We study the consequences of such mismatches on a…

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astro-ph.EPmath.DSphysics.space-ph

A Semi-Analytical Theory for Improved Orbit Design of the GARATÉA-L

Luiz Arthur Gagg Filho, Sandro da Silva Fernandes

This work proposes a semi-analytical theory for improving orbit design of the GARATÉA-L Brazilian lunar mission. The dynamical model incorporates the lunar gravitational potential up to degree 12 and order 3 harmonics and a third-body perturbation model accounting for the eccentricity and inclination of the Earth's orbit with respect to the Moon. Through Hori's method, short- and medium-period terms are eliminated from the Hamiltonian to derive a first-order theory in mean orbital elements. It i…

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astro-ph.COastro-ph.HEastro-ph.IM

A stochastic forward model for the intergalactic dispersion-measure distribution of Fast Radio Bursts

Jéferson A. S. Fortunato, Valerio Marra, Wiliam S. Hipólito-Ricaldi, Amanda Weltman

Fast Radio Bursts probe ionised baryons through their observed dispersion measures. We present \turbofrb, a semi-analytic stochastic forward model for the intergalactic dispersion-measure distribution, $P({\rm DM}_{\rm IGM}\mid z)$, that resolves the diffuse IGM, halo, and filament contributions as explicit physical channels, with the halo and filament encounter rates coupled by a latent line-of-sight environmental variable. Only four effective parameters are calibrated against hydrodynamical ra…

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astro-ph.HE

Revisiting neutrino event epochs for the blazar PKS 0735+178 with TESS

Shubham Kishore, Alok C. Gupta, Debanjan Bose

We present here the results of the optical light curve variability analysis of the blazars PKS 0735+178, in weeks-scale flare state, observed in three sectors with the Transiting Exoplanet Survey Satellite (TESS). The TESS observations in this study coincide with a well-known neutrino emission phase detected with four different neutrino observatories at multiple epochs in a narrow time window. We segmented the rising and decaying parts of the flare and individually analyzed their flux distributi…

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astro-ph.HEastro-ph.IM

SST-1M: Recent results and prospects for observation of the Galactic Center region

Jakub Juryšek, for the SST-1M Collaboration

The Galactic Center is a crowded region containing powerful particle accelerators and objects producing non-thermal radiation, including the diffuse very-high-energy (VHE) gamma-ray component known as the `Ridge', whose hard spectrum suggests particle acceleration up to PeV energies. The relevant processes can be tested, and the source parameters can be constrained via Cherenkov telescope observations. Two Single-Mirror Small-Size Cherenkov Telescopes (SST-1M) are currently operated in stereosco…

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astro-ph.SR

Complex morphology and kinematics at the heart of the very low luminosity object IRAM 04191+1522

N. Otten, I. de Gregorio-Monsalvo, N. Huélamo, E. Artur de la Villarmois, G. Blazquez Calero, E. Whelan

The formation of the majority of brown dwarfs (BDs) remains uncertain. They may form in molecular cloud cores in a process akin to low mass star formation, or via fragmentation in circumstellar discs. Studying the youngest, most embedded sources is crucial for distinguishing these scenarios. We investigate molecular gas morphology and kinematics around one young & embedded very low luminosity object (VeLLO), IRAM 04191+1522, utilising archival ALMA observations of 13CO, C18O, and SO. We trace ga…

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astro-ph.EPphysics.space-ph

The PANSY Meteor Head-echo Orbit Catalogue: Continuous Antarctic Radar Observations of Southern Meteoroid Streams

Juha Vierinen, Jorge L. Chau, Koji Nishimura, Taishi Hashimoto, Nico Pfeffer, Daniel Kastinen, Devin R. Huyghebaert, Johan Kero et al.

Meteor head echoes from high-power, large-aperture radars provide pulse-resolved positions and velocities for individual micrometeoroids in a submillimeter-radius range that contribute significantly to the mass influx to Earth. We present the first meteor head-echo orbit catalogue from the Antarctic Syowa Mesosphere--Stratosphere--Troposphere/Incoherent Scatter radar (PANSY). The catalogue contains two million meteors and 50 million pulse-resolved measurements. The observed radiant distribution…

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astro-ph.COastro-ph.GA

Dianoga simulations of galaxy clusters and groups: Properties of the baryonic components

Stefano Borgani, Alice Damiano, Elena Rasia, Tiago Castro, Michela Esposito, Ilaria Marini, Giuseppe Murante, Milena Valentini et al.

We introduce the Dianoga set of cosmological simulations of galaxy clusters and groups, specifically aimed at studying the impact of the implementation of AGN feedback and star formation. Using the OpenGadget3 code, we carry out simulations of 28 regions centred on massive galaxy clusters, and of a cosmological box. This generates a sample of 293 halos with M_{200}> 1.5 x 10^{13} M_{\odot}. Parameters of AGN feedback in the reference implementation were minimally calibrated exclusively to match…

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astro-ph.HEastro-ph.IM

NMMA-Astro-COLIBRI: An Automated Light-Curve Supernovae Classification Service in the Multi-Survey Era

R. Weizmann Kiendrebeogo, Bernardo Cornejo Avila, Sofia Bisero, Maxime Cellier, Antoine Ciric, Ilja Jaroschewski, Henrik Rose, Alexandre Saint-Paul et al.

The surge in publicly available photometric alerts from wide-field surveys requires automated tools for real-time transient classification. We present NMMA--Astro-COLIBRI, an on-demand Bayesian classification service that couples the Nuclear-physics and Multi-Messenger Astrophysics (NMMA) inference framework to the Astro-COLIBRI real-time multi-messenger platform. After the detection of an optical transient, if photometry is available, it is quality-filtered. The filtered photometry is fitted by…

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astro-ph.HEastro-ph.GA

From Variability to SED Modeling: A Multiwavelength Study of the Neutrino Blazar TXS 0506+056

Shiyu Du, Hanxiao Xia, Jianghua Wu, Yue Fang

The blazar TXS 0506+056 is the first source that was reported to be associated with high-energy extragalactic neutrino events and is one of the major targets for multi-messenger studies. We carried out multi-wavelength optical monitoring of this object on 24 nights in the period from 2018 to 2023. The overall light curves exhibit a dimming trend superposed by some small-amplitude fluctuations, and intraday variability was detected on four nights. Bluer-when-brighter behaviors were observed on bo…

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astro-ph.HEgr-qc

Modelling mountains on accreting magnetized neutron stars

T. Brusco, B. Haskell, M. Razzano, M. Bejger, J. L. Zdunik

Continuous gravitational waves from accreting neutron stars in Low Mass X-ray Binaries are one of the main targets for current and next generation ground based detectors. In order to select the most promising astrophysical sources, however, reliable predictions for the signals are required, and it is therefore necessary to develop models that consistently account for the combined effects of magnetic stresses, accretion-induced heating, and the elastic response of the crust.}{We present a model f…

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astro-ph.SRastro-ph.GA

Modelling s-process chemical clocks: insights from high-precision Kepler data

G. Casali, M. Molero

We present Galactic chemical evolution (GCE) models for the chemical clocks [Zr/Ti] and [Ce/Ti], tracing first- and second-peak s-process nucleosynthesis, and compare them with a high-precision sample of 68 Kepler red giant stars with asteroseismic ages from individual-mode frequencies and high-resolution spectroscopy. Using a multi-zone GCE framework, we explore variations in metallicity-dependent asymptotic giant branch (AGB) nucleosynthetic yields, including proposed enhancements to high-meta…

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astro-ph.HE

Impact of Upstream Clumpiness on Supernova Remnant Forward Shock Evolution in Molecular Cloud Environments

Kenta Tatsumi, Tsuyoshi Inoue

Supernova remnants (SNRs) are widely considered to be the primary accelerators of Galactic cosmic rays. In recent years, detailed observations have significantly progressed for young SNRs interacting with molecular clouds, a prime example being RX J1713.7-3946. When molecular clouds are clumpy, their impact can affect not only radiation properties but also shock wave propagation. Therefore, a quantitative understanding linking observational quantities with the ambient medium structure is highly…

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