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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。

physics.comp-phastro-ph.IMmath.NA

Adding slow magnetoacoustic mode to the HLL-type multi-state approximate Riemann solution

Fan Zhang, Stefaan Poedts, Andrea Lani

Multi-state HLL-type approximate Riemann solutions of ideal magnetohydrodynamics (MHD) typically assume that the medium within the Riemann fan is incompressible, and thus the slow magnetoacoustic mode cannot be included in their space-time wave configurations for the approximated states. We propose a new strategy to design multi-state HLL-type approximate solutions, allowing for the medium within the Riemann fan to be compressible. In particular, for the complete seven-wave configuration of the…

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

Stellar age is not disk age

M. Kuffmeier, A. Winter, A. Kuznetsova, M. Vioque, A. Gupta

Disk fractions in star-forming clusters decline with stellar age, and are routinely read as the lifetime distribution of primordial protoplanetary disks. We argue that this reading is not warranted, because late infall can replenish or reform disks after collapse. To formalize this, we model the disk fraction as a superposition of primordial and environmentally replenished components, with region-to-region dispersion in the supply rate. Disk fractions cannot distinguish a long-lived disk from a…

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astro-ph.IMastro-ph.GA

IViS: Interferometric Visibility-domain inversion Software - A GPU-accelerated Python framework for joint deconvolution with ASKAP

A. Marchal, N. M. McClure-Griffiths, J. Dempsey, H. Nguyen, H. Dénes, J. Dickey, C. Lynn, Y. K. Ma et al.

Wide-field spectral-line imaging with modern radio interferometers remains challenging when the emission is extended, multiscale, and distributed over many overlapping pointings. Accurate reconstruction requires joint treatment of the calibrated visibilities, control of image-domain regularity, and recovery of missing short spacings from single-dish data. We present IViS (Interferometric Visibility-domain Inversion Software), a GPU-accelerated Python framework for visibility-domain joint deconvo…

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astro-ph.GA

How Small is Large Enough? Determining Minimal Cluster Sizes for Molecule Adsorption on Interstellar Amorphous Ice

Erik C. Neyts, Christopher King, Irina Grubova, Tobe Vorsselmans

Binding energies of molecules on ice mantles are important to understand the evolution of molecular complexity in molecular clouds. Binding energies are often computed using density functional theory (DFT) calculations, typically on either small amorphous ice clusters or crystalline slabs. Since these calculations require an accurate description of the electronic structure, hybrid functionals with dispersion corrections, basis set superposition error corrections and zero point energy corrections…

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astro-ph.GA

How Small is Large Enough? Determining Minimal Cluster Sizes for Molecule Adsorption on Interstellar Amorphous Ice

Erik C. Neyts, Christopher King, Irina Grubova, Tobe Vorsselmans

Binding energies of molecules on ice mantles are important to understand the evolution of molecular complexity in molecular clouds. They are often computed using density functional theory (DFT) calculations, typically on either small amorphous ice clusters or crystalline slabs. Since these calculations require an accurate description of the electronic structure, hybrid functionals with dispersion corrections, basis set superposition error corrections and zero point energy corrections are typical…

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astro-ph.EP

Saturns Are Not Large Neptunes: The effect of removing inflated giants from empirical mass-radius relations

Georgina Dransfield, Valentina Tardugno, Niamh K. O'Sullivan

Empirical mass-radius relations have long been used in exoplanetology to study planet demographics and to predict masses and radii for objects where only one of these is known. Inferred transitions between planet classes can also provide empirical evidence in support of theory. However, mass-radius relations fitted in two-dimensions can be complicated when additional factors influence the planetary parameters, as is the case with the radius inflation of giant planets. In this work, we present an…

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astro-ph.SRastro-ph.EP

The evolution of discs and the epoch of formation\newline of giant planets around solar type stars

Raffaele Gratton, Elisabetta Rigliaco

Disc evolution dictates the time for planet formation providing the raw material to build the planets' cores. Dynamical stellar masses derived from the kinematics of the gas in discs provide constraints on the ages of very young stars, offering a powerful approach to studying disc evolution and the epoch of giant-planet formation. We investigated a sample of 33 solar-type stars with bright protoplanetary discs and ages between 1 and 9\,Myr. We modeled the spectral energy distributions and ALMA d…

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astro-ph.SRastro-ph.EP

The evolution of discs and the epoch of formation of giant planets around solar type stars

Raffaele Gratton, Elisabetta Rigliaco

Disc evolution dictates the time for planet formation providing the raw material to build the planets' cores. Dynamical stellar masses derived from the kinematics of the gas in discs provide constraints on the ages of very young stars, offering a powerful approach to studying disc evolution and the epoch of giant-planet formation. We investigated a sample of 33 solar-type stars with bright protoplanetary discs and ages between 1 and 9\,Myr. We modeled the spectral energy distributions and ALMA d…

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astro-ph.IMphysics.optics

Optimal exposure time for satellite imaging? A trade-off between residual tip-tilt and registration accuracy

Florian Cheyssial, Laurent M. Mugnier, Cyril Petit

Adaptive-Optics assisted astronomical imaging and satellite imaging from the ground share many commonalities but have also specificities. In particular satellites are non-stationary objects in terms of both shape and flux, encouraging relatively short exposure times. Besides, very short exposures freeze the turbulence and preserve high spatial frequency information in speckles, but at the cost of a low image SNR, which complicates the post-processing. Conversely, long exposures lead to speckle-l…

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astro-ph.EPastro-ph.SR

Around the water snowline: I. Effects of dynamical and chemical interplay on mid-infrared water spectra of protoplanetary discs

Till Kaeufer, Sebastiaan Krijt, Edwin A. Bergin, Andrea Banzatti, Joe Williams

Protoplanetary discs' infrared water spectra (e.g. as observed by JWST) encode information about the underlying water distribution and physical conditions. In this work, we examine and quantify the imprint of various dynamical processes (operating alone or in unison) on water abundances and emerging spectra using a new 2D model called Molecular emission Affected by Gas, Pebble, and Ice Evolution (MAGPIE). This model combines diffusion and advection for water (and associated species) and dust gra…

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gr-qcastro-ph.HE

Impact of the Host Galaxy on the Search for Gravitational-Wave Microlensing by Compact Objects

Uddeepta Deka, Apratim Ganguly, Soham Bhattacharyya, Parameswaran Ajith

Gravitational-wave (GW) microlensing occurs when an intervening compact object causes diffraction of the GW, imprinting characteristic frequency-dependent modulations on the observed signal. Current searches for microlensing signatures in the detected GW events, including those used to constrain the fraction of dark matter in the form of compact objects, assume an isolated point mass lens (PML) model. However, astrophysical compact objects are typically embedded within larger structures, such as…

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astro-ph.GA

Pushing HST to the limit: Detection completeness and morphology robustness of faint galaxies in the EGS field

Limin Lai, Zhao-Yu Li, Chao Ma, Yang Anpin Li, Luis C. Ho, Mingyang Zhuang

Reliable catalogs at the faint limit are essential for statistical studies of galaxy evolution. However, detection and structural measurements of faint galaxies remain challenging. We evaluate detection completeness and structural parameter uncertainties of faint galaxies in the CANDELS/EGS field using mock images and observations from the HST and JWST. The framework is also applicable to large high-redshift surveys, including Euclid, the upcoming CSST, and the Nancy Grace Roman Space Telescope.…

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astro-ph.IM

Hardware-efficient neural networks for FPGA-based radio triggering of extensive air showers

Vesselin Dimitrov, Alperen Aksoy, Ilja Bekman, Markus Cristinziani, Eric-Teunis de Boone, Qader Dorosti, Chimezie Eguzo, Stefan Heidbrink et al.

We present a hardware-efficient hybrid trigger for FPGA-based radio detection of extensive air showers. The hybrid design consists of a lightweight denoiser that cleans raw ADC traces and a compact classifier that operates on the denoised output, enabling robust near-threshold pulse detection in high-interference environments. Both neural networks are trained quantization-aware. Signals are generated from detector-folded CoREAS/CORSIKA simulations and embedded into measured noise to form a reali…

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astro-ph.GAastro-ph.CO

The UV-to-FIR environments of nearby Type Ia supernovae with the DustPedia Galaxy Catalogue -- I. Local versus global host properties

Lisa Kelsey

The ongoing use of Type Ia Supernovae (SNe Ia) as standardisable candles relies on an additional correction for the relationship between their standardised brightnesses and host galaxy properties. Currently, this correction is built on host stellar mass, typically derived from optical-only SED fitting, which recent analyses suggest may not fully capture the underlying environmental properties. This relationship is stronger when considering the regions closest to the SNe, rather than the galaxies…

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astro-ph.GA

An ALMA Band 7 survey of SDSS/Herschel quasars in Stripe 82: II. The nature of FIR-bright quasars

Evanthia Hatziminaoglou, Hugo Messias, Duncan Farrah, Anna Feltre, Dennis Koopmans, Ismael Perez-Fournon, Rhimon Souza, Lingyu Wang et al.

We investigate the star formation properties and ultraviolet (UV)/optical spectral characteristics of 142 far-infrared (FIR)-bright quasars at redshifts 1 2 for FIR-blended multi-component systems, while reducing FIR luminosity uncertainties by ~18%. The revised host SFRs span 500 and 3000 solar masses per year (median 1080 solar masses per year), confirming these systems are extreme starbursts. The very shallow positive correlation between starburst and accretion luminosities suggests that SMBH…

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astro-ph.SR

Promise and pitfalls of plasma emission as an exo-space-weather tool

Ivey Davis

Significant observational effort has been spent on identifying stellar analogues to solar type II and III bursts, which are plasma emission that is produced when coronal mass ejections and fast electron beams, respectively, propagate through the corona and wind. The sensitivity of these bursts to ambient plasma and their association with energetic transient particle flux makes them powerful diagnostics of exo-solar space weather. However, analyses of stellar bursts often rely on the assumption t…

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astro-ph.GAgr-qc

Gravitational lensing of gravitational waves by galaxy clusters

Xikai Shan, Yi-Fan Wang, Shude Mao, Huan Yang, Miguel Zumalacárregui

Strongly lensed gravitational waves (GWs) are commonly searched for using population priors, including time-delay and magnification-ratio distributions, to suppress false alarms. Current LIGO, Virgo, and KAGRA (LVK) searches mainly adopt priors calibrated with galaxy-scale lenses; however, these may penalize the longer time delays produced by galaxy clusters, which could contribute 10%--20% of lensed events. Cluster member galaxies may also perturb the macro-lens potential and alter image magnif…

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astro-ph.GA

Supernova Kinetic Yield oN galactic Emission Tracers (SKYNET) I. Contribution of radiative supernova remnants to Galactic N + emission

Guillaume Vigoureux, Benjamin Godard, Antoine Gusdorf, Guillaume Pineau Des Forêts

Context. The radiative stage of a supernova remnant (SNR) constitutes approximately 90% of its lifetime. Yet, only a few tens of radiative supernova remnants (r-SNRs) have been observed in the Milky Way, while catalogs of young SNRs in their adiabatic stage contain $\sim$ 300 -400 confirmed sources. This deficit reflects the absence of unambiguous tracers for the radiative phase, and stands as a major obstacle to understanding the impact of SNRs on the energetic balance and the chemical state of…

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astro-ph.HE

Impact of Equation of State on Black Hole Accretion Flows and Radiative Properties

Yun-Ming Zhu, Indu K. Dihingia, Yosuke Mizuno, Ziri Younsi, Christian M. Fromm

Previous literature has documented that black hole shadow images are mainly shaped by spacetime geometry and plasma microphysics governing accretion flows. However, the influence of equations of state (EoS) remains under-explored. In this paper, we quantify how different plasma microphysics prescriptions, specifically the choice of EoS and electron-heating models, affect flow thermodynamics and the corresponding synthetic black-hole images. We perform three-dimensional general-relativistic magne…

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astro-ph.SR

Triple coronal hard X-ray source observed by STIX during a failed filament eruption

Tomasz Mrozek, Marek Stęślicki, Sylwester Kołomański, Krzysztof Barczynski

{Observations reveal hard X-ray sources in the solar corona with morphologies and locations distinct from typical solar flares. One expected mechanisms for hard X-ray (HXR) production in the solar corona is eruptions of various types. Failed eruptions are promising targets for detecting non-flare-related HXR sources because most of their energy is expected to be dissipated in the corona. } {We investigated the SOL2022-0 to determine the nature of coronal HXR sources associated with the event.} {…

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astro-ph.EP

The asymmetric limbs of HD 209458 b observed with JWST NIRCam F322W2/F444W

Cathal Maguire, Eva-Maria Ahrer, Charlotte Fairman, Hannah R. Wakeford, Duncan Christie, James Kirk, Elspeth K. Lee, Evert Nasedkin et al.

We present a reanalysis of JWST NIRCam F322W2/F444W transit observations of the hot Jupiter HD 209458 b to extract morning and evening transmission spectra. To determine whether asymmetries in the transit light curves arise from atmospheric structure, we refine the HD 209458 system parameters through a reanalysis of archival transit and radial velocity data. We then extract limb-resolved spectra using two independent light curve modelling frameworks, Harmonica and catwoman,which yield consistent…

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astro-ph.HEastro-ph.SR

Testing a Pre-Supernova Contribution to $^{44}$Ti in Cassiopeia A

Toshiki Sato, Joshua Issa, Falk Herwig, Yui Kuboike, J. Martin Laming, Kai Matsunaga, Ryo Sawada

The radioactive isotope $^{44}$Ti in Cassiopeia A has been used as a tracer of the innermost ejecta and explosion asymmetries in core-collapse supernova explosions. However, recent stellar-evolution models suggest substantial $^{44}$Ti may also be synthesized prior to explosion during oxygen-carbon (O-C) shell mergers, a process proposed for the Cas A progenitor. We investigate this pre-supernova contribution by combining NuSTAR measurements of the spatial and kinematic distribution of $^{44}$Ti…

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astro-ph.EP

H$_2$O emission as tracer of pebble drift: insights from coupling transport and thermochemical models

Marissa Vlasblom, Andrew D. Sellek, Ewine F. van Dishoeck

(Abridged) The composition of the inner regions of protoplanetary disks is known to change with time due to the delivery of icy grains. Cold H$_2$O emission seen with JWST-MIRI is often hypothesized to be a tracer of this pebble drift. However, it is unclear to what extent processes such as photodissociation or the co-delivery of dust may impede such detections. We aim to obtain an improved, 2D view of transport in disks, to better understand how these processes can be traced by H$_2$O emission…

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astro-ph.SRastro-ph.GA

The study of AF And. I. Hydrogen abundance constraints and dynamically-consistent wind model of the hot state

E. O. Dedov, A. E. Kostenkov, A. S. Vinokurov, A. N. Sarkisyan

This paper starts a series of works devoted to an in-depth study of luminous blue variable AF And in the M31 galaxy. Here we present the results of non-LTE modelling of the star in a hot state with CMFGEN code. In addition to the $β$-velocity law, widely used in the analysis of stellar atmospheres, we used a velocity distribution obtained from the balance of radial forces in the wind, including centrifugal forces for several models. Such a dynamically consistent approach reduces the parameter sp…

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astro-ph.HEastro-ph.SR

Population synthesis of low-mass binaries with wind-accreting neutron stars

Marina Afonina, Sergei Popov

We perform population synthesis modeling of neutron star binary systems containing a low-mass main-sequence companion underfilling its Roche lobe. About $10^5$ such systems are expected to exist in the Milky Way. In the majority of such systems, NSs are expected to start accreting the stellar wind matter within a few Gyr, resulting in the appearance of a dim X-ray source. The exact value of this fraction mainly depends on the efficiency of the propeller spin-down, properties of the stellar wind,…

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astro-ph.GA

Lower central dark matter densities in nearby galaxies than predicted by simulations

Yu Lei, Ling Zhu, Meng Yang, Giulia Despali, Zheng Zheng, Ran Li, Dandan Xu, Niankun Yu et al.

Baryonic feedback in hydrodynamical simulations is typically invoked to alleviate the core--cusp problem in dwarf galaxies. Yet baryonic processes also induce adiabatic contraction of dark matter, producing overly steep density profiles and excessively high dark matter fractions in the inner regions of massive galaxies. The dark matter distribution of galaxies across a wide stellar-mass range is therefore a critical test for such simulations, but a comprehensive benchmark has remained absent. He…

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astro-ph.EP

Discovery of radio emission from the exoplanet $β$ Pictoris b

Kevin N. Ortiz Ceballos, Edo Berger, Yvette Cendes

Planetary magnetic fields shape atmospheric escape, mediate interactions with stellar winds, and encode information about planetary interiors, yet they have not been directly measured for planets beyond the Solar System. A direct observable signature is auroral radio emission produced by the electron cyclotron maser instability, whose highest emitted frequency is set by the magnetic field strength at its source. Although auroral radio bursts are observed in Solar System planets and in some ultra…

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astro-ph.GA

Probing the All-sky Distribution of Soft X-ray Emission Associated with the Milky Way

Kazuki Ampuku, Ikuyuki Mitsuishi, Philip Kaaret, Kyoko Matsushita, Kotaro Fukushima, Lorella Angelini, Dimitra Koutroumpa, K. D. Kuntz et al.

We present an all-sky analysis of soft X-ray emission associated with the Milky Way using HaloSat and ROSAT data, extending our previous study of five Galactic-plane regions to 330 fields across the sky. We performed uniform spectral fitting with a model including an unabsorbed Local Hot Bubble and two additional absorbed thermal components, representing emission from warm-hot and hot plasma, while accounting for solar wind charge exchange and the cosmic X-ray background. The warm hot component…

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gr-qcastro-ph.HE

An Operative Viability Boundary for Relaxed Single-Particle Penrose Extraction in Kerr-Vaidya Spacetimes

Fabio Buffoli

We present a corrected numerical investigation of the Penrose process in the Kerr-Vaidya metric for a rotating black hole losing mass at constant rate. We fix two errors from an earlier version: an incorrect metric component g_r phi (verified by transformation from Boyer-Lindquist coordinates) and the omission of the Wald/Christodoulou area theorem in the split optimization. Using the standard single-particle treatment (energy and angular momentum conserved at the split, but not the escaping fra…

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