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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.IM

The EDD Radio Astronomy Backend Framework

Ewan D. Barr, Amit Bansod, Jan Behrend, Weiwei Chen, Niclas Esser, Yungpen Men, Tobias Winchen, Jason Wu et al.

Modern digital radio astronomy receivers produce increasingly wide-bandwidth, high bit-rate data streams that necessitate the development of flexible, scalable, and maintainable backend processing and recording systems. Historically, such backend instrumentation has been tightly coupled to telescope observing modes, limiting reuse between observatories and science cases. We present the Effelsberg Direct Digitisation (EDD) backend framework, a software-defined architecture for constructing real-t…

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astro-ph.IMastro-ph.EPq-bio.PE

A Framework for Evaluating Forward Contamination Risk for Bio-ISRU Microorganisms

Una Nattermann, Devon A. Stork, Tom Pedersen, Nathan D. Hicks, Jordan E. Mancuso, Keren Isaev, Max G. Schubert, Fatima R. Martin et al.

NASA planetary protection policy seeks to avoid inadvertent forward contamination of celestial bodies and backward contamination of Earth during space exploration. For Mars missions, it has historically focused on sterilization of landers and rovers. Current policy provides no framework for assessing the forward contamination risk of missions that deliberately include living organisms and must not be sterilized, such as a human crew, agriculture, or biotechnology for manufacturing and life suppo…

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astro-ph.SR

Statistical evidence for linear combination frequencies in γ Doradus stars being nonlinear resonant modes

Yanqi Mo, Weikai Zong, Xuan Wang, Jian-Ning Fu, Xiao-Yu Ma, Mingfeng Qin, Stéphane Charpinet

The quest for the origin of linear combination frequencies in pulsating stars is critical for mode identification and subsequent seismic modeling. Hybrid γ Doradus (Dor) stars provide a crucial testbed for such investigations due to their rich frequency content in both gravity (g) and pressure (p) modes. Here, we performed a comprehensive survey of 608 Kepler γ Dor stars, detecting 81,265 frequencies, and identifying 1,895 harmonics and 45,968 combinations involving two parent frequencies. Our r…

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astro-ph.GA

Nitrogen-Loud Quasars from the Dark Energy Spectroscopic Instrument. I. Sample Selection and Basic Properties

Shuo Zhai, Wei-Jian Guo, Yong-Jie Chen, Zhi-Qiang Chen, Haining Li, Jian-Min Wang, Gang Zhao

We present the largest sample to date of nitrogen-loud (N-loud) quasars with strong broad N IV] $\lambda1486$ and/or N III] $\lambda1750$ emission lines over the redshift range $1.6 < z < 4.3$, selected from the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. The final sample contains 1,993 N-loud quasars, corresponding to about 1.2% of the parent quasar sample. The $L_{1450}$ distribution of the N-loud quasars is broadly similar to that of the DESI parent sample, but their redshift…

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astro-ph.IMastro-ph.HE

Astrophysics in the Era of Artificial Intelligence powered by Large Language Models

A. R. Rao

In recent times there is considerable unease about the way Artificial Intelligence (AI) powered by large language models is used to do astrophysics, and, assuming that these AIs will get far better in future, several alarming situations are also discussed. In a ``white paper,'' Hogg argues that extreme cases like allowing AI to write all astrophysics papers or strictly controlling AI are not good choices and posits that it is difficult to adopt moderate policies. I examine the impact of AI on as…

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astro-ph.GA

SPURS: An Ultra-deep View Inside the Compact, Nitrogen-Enriched Nuclei of Little Red Dots

Mengtao Tang, Daniel P. Stark, Charlotte A. Mason, Zuyi Chen, Tucker Jones, Sarah Searle Grannis, Peter Senchyna, Lily Whitler et al.

We present the first ultra-deep rest-UV spectroscopy of four UV-bright Little Red Dots (LRDs), obtained from the SPURS Cycle 4 Large Program. The spectra reveal broad CIV (FWHM $\approx2700-2800$ km s$^{-1}$) in two LRDs, alongside narrow-line densities elevated above star-forming galaxies ($n_e\sim10^4-10^5$ cm$^{-3}$, reaching $10^6$ cm$^{-3}$ in the most extreme source) and nitrogen-enhancements in all four LRDs. We detect broad HeII emission (FWHM $\approx930$ km s$^{-1}$) in one LRD, and tw…

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astro-ph.HEastro-ph.SR

Evidence for the binary nature of the long-period radio transient ASKAP/DART J1832-0911

Csanád Horváth, Natasha Hurley-Walker, Ziteng Wang, Andrew Zic, Emil Lenc

Long-period transients are a class of periodic pulsed radio source repeating on the minute to hour timescale. Recently, an increasing number of them are being identified as binary systems, specifically white dwarfs with low-mass main-sequence companions. In this work we analyse the most luminous long-period transient discovered to date, ASKAP/DART J1832-0911, with two years of radio data, and propose that it, too, may be a white dwarf system, although in a far more compact orbit than the aforeme…

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astro-ph.SRastro-ph.GA

Uncovering the Origin of Slow Rotators among Intermediate-Mass Stars in the Star-Forming Cluster Trumpler 14

Khushboo K. Rao, Wen-Ping Chen, Hsiang-Yu Chen, Kristen Dage, Stella S. R. Offner

Intermediate-mass (about 1.5-8 M$_{\odot}$) stars exhibit a wide range of rotation rates and have gained attention for their roles in the extended main-sequence turnoffs (eMSTO) seen in some young and intermediate-age clusters (ages $< 2$ Gyr). Although rapid rotation is expected due to their radiative envelopes, the presence of slow rotators remains puzzling. In this study, we examine disk and X-ray signatures among the intermediate-mass members of the star-forming cluster Trumpler 14. Of the 1…

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astro-ph.SRastro-ph.HE

A prolonged plateau-to-tail transition in the Type II supernova SN2025abyc

Luhan Li, Bo Wang, Jujia Zhang, Zhengyang Zhang, Xinjie Luo, Shiyang Dong, Saien Xu, Zhengwei Liu et al.

We present optical photometric and spectroscopic observations of the Type II supernova SN2025abyc. During the optically thick phase between approximately 10 and 70 d after explosion, its light curves show strongly wavelength-dependent decline rates of approximately 2.7, 2.1, 0.9, and 0.8 mag/100d in the g, c, r, and o bands, respectively. At approximately 70 d, the light curves begin to depart from their nearly linear plateau evolution and gradually transition toward the radioactive tail. A Ferm…

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astro-ph.SRastro-ph.IM

Science operation, data handling, and ground support system of the SOLAR-C mission

Shin Toriumi, Mari Nishiyama, Keiichi Matsuzaki, Toshifumi Shimizu, Hideki Kato, Jun Matsumoto, Mizuho Uchiyama, Kota Miyoshi et al.

SOLAR-C is an international solar-observing satellite mission led by Japan Aerospace Exploration Agency (JAXA). It aims to elucidate mass and energy transport in solar atmospheres through extreme ultraviolet (EUV) spectroscopy. The mission carries the EUV High-throughput Spectroscopic Telescope (EUVST) and the Solar Spectral Irradiance Monitor (SoSpIM), enabling comprehensive observations across a wide temperature range (10^4 K to 10^7 K) with minimum temperature gaps and high spatial and tempor…

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astro-ph.SR

Classical Nova V1405 Cas Had $M_{\rm ejecta}$$>$$M_{\rm accreted}$ and so is Unlikely to be a Type Ia Supernova Progenitor

Bradley E. Schaefer

Nova 2021 Cassiopeia (V1405 Cas) was an ordinary J(175) neon nova with the white dwarf mass estimated to be $M_{\rm WD}$=0.60$\pm$0.10 $M_{\odot}$. I found an orbital period of $P$=0.1884 days, and have tracked 20 times of photometric minima from 2013--2025. I measure that $P$ increased from before to after the eruption with $P_{\rm pre}$=0.1883919$\pm$0.0000018 days and $P_{\rm post}$=0.1884043$\pm$0.0000018 days, for $ΔP$/$P$=66$_{-18}^{+21}$ parts-per-million. With correction for the angular…

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astro-ph.SR

Eclipse Properties and Superhump Evolution in the SU UMa-Type Dwarf Nova Z Cha

Qi-Bin Sun, Sheng-Bang Qian, Li-Ying Zhu, Qin-Mei Li, Wen-Ping Liao, Fu-Xing Li, Wen-xu Lin, Min-Yu Li et al.

The advent of large-scale time-domain surveys provides both opportunities and challenges for understanding accretion disk evolution in cataclysmic variables (CVs). Using high-cadence photometry from the Transiting Exoplanet Survey Satellite (TESS), we investigate the eclipsing SU UMa-type dwarf nova Z Cha. Leveraging eclipses as a natural probe, we examine the evolution of the accretion disk through variations in eclipse depth, O--C of eclipse minima, and positive superhump (PSH) amplitude. Duri…

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astro-ph.GA

Fast Dynamical Modelling of Milky Way Globular Clusters -- II. Impacts of Black Hole Prescriptions

Nolan Dickson, Vincent Hénault-Brunet, Fotios Fronimos Pouliasis, Mark Gieles, Daniel Marín Pina, Peter J. Smith

The populations of stellar-mass black holes (BHs) in globular clusters (GCs) play a key role in their dynamical evolution, however the mechanisms surrounding their formation and retention are uncertain. In this work, we extend the analysis of Paper I by fitting coupled rapid cluster evolution and multimass equilibrium models to a large sample of Milky Way GCs, under a variety of prescriptions for stellar evolution, BH formation and supernovae (SN) natal kicks. We explore the impacts of adopting…

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astro-ph.HE

IceCube neutrino point-source searches in the direction of the KM3NeT ultra-high-energy event

R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, J. M. Alameddine, S. Ali, N. M. Amin et al.

While still under construction, the KM3NeT Astroparticle Research with Cosmics in the Abyss (ARCA) detector recorded a $\sim$200 PeV neutrino on February 13th, 2023. This event is the highest-energy neutrino reported. IceCube, a cubic kilometer neutrino detector located at the geographic South Pole, has previously detected neutrinos up to approximately 10 PeV. We search for high-energy neutrinos from the location of the KM3NeT event using 15 years of IceCube data and considering three temporal h…

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astro-ph.IM

Towards High-Throughput Visible Photonic Lanterns for the EMARCOT Project

Abani Shankar Nayak, Julius Goehring, Marina Centenera-Merino, Pedro José Amado-González, David Pérez-Medialdea, Mabel Ruiz-Lopez, Francisco J. Pozuelos, Miguel Andrés Sánchez Carrasco et al.

Photonic EMARCOT is an innovative project involving Spanish, German and Australian research institutes that aims to integrate multiple Optical Tube Assemblies (OTAs) using photonic lanterns. The "Pathfinder" prototype, featuring seven OTAs with a 1.1-meter effective aperture, will feed a spectrograph at the Calar Alto Observatory, with first light expected in 2026. We report the fabrication and experimental evaluation of a custom 7x1 multi-mode photonic lantern (MMPL) developed for this framewor…

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astro-ph.GAastro-ph.CO

Impact of LSST systematics on stellar-stream density fluctuations for dark matter

Matthieu Pélissier, Peter S. Ferguson, Alex Drlica-Wagner, Marine Kuna, David Maurin, Christian Aganze, Johann Cohen-Tanugi, Yao-Yuan Mao et al.

The Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) is expected to significantly advance the study of Milky Way stellar streams. In particular, the deep, precise photometry from LSST should greatly increase the statistical sensitivity to density fluctuations in stellar streams, which can be used to probe the small-scale distribution of dark matter. However, current forecasts generally neglect the impact of observational systematics that will be imprinted on stream density meas…

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astro-ph.GA

Studying Outflows with Synthetic Absorption Line Spectra from High Resolution Simulations

Jake Magee, Evan Schneider, Kate H. R. Rubin, S. Alwin Mao, Cameron Hummels

Down-the-barrel absorption line spectra are a powerful probe of the properties of multiphase galactic outflows. In this work, we demonstrate a method to generate realistic synthetic spectra using high resolution ($Δx=5-20 \ \mathrm{pc}$), 20-kiloparsec-scale outflow simulations from the next generation of the CGOLS project. Aiming to mimic modern observational surveys of nearby star-forming galaxies, we generate a suite of UV absorption lines, from which we measure common observables such as equ…

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astro-ph.EPastro-ph.SR

Constraining Tidal Migration with the Hot Jupiter Population

Linhao Ma, Yubo Su, Samuel W. Yee, Caleb Lammers, Eliot Quataert, Joshua N. Winn

Hot Jupiters with orbital periods shorter than a few days have probably been affected by tidal orbital migration. We develop an analytical framework for constraining tidal migration from the present-day hot Jupiter period distribution, taking into account the uncertain rate and period distribution of hot Jupiters produced by mechanisms such as high-eccentricity migration or disk-driven migration. Assuming the tidal migration timescale is proportional to $P^{χ_τ}$, solutions with $χ_τ\simeq 3, 1.…

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astro-ph.HEastro-ph.GA

XRISM observations of the Perseus cluster along two arms: Chaotic ICM motions probed by resonant scattering

Annie Heinrich, Irina Zhuravleva, Congyao Zhang, Anna Ogorzalek, Ayşegül Tümer, François Mernier, Phillip C. Stancil, Elena Bellomi et al.

XRISM has mapped gas velocities across the core of the Perseus cluster, separating the kinematic effects of mergers and AGN feedback. The physical properties of these motions remain unclear: are they a superposition of bulk flows, predominantly random/turbulent motions, or a mixture of both? Without resolving this question, constraints on the nonthermal pressure fraction and heating rate remain uncertain, as both assume predominantly random motions. Unlike emission line broadening, resonant scat…

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astro-ph.SRastro-ph.HE

Frozen-composition effects on rotational failure of neutron-star crusts

Elia Giliberti

The elastic response of a neutron-star crust to rotational loading depends on whether weak interactions can restore chemical equilibrium during the deformation. We quantify this effect using unified equations of state and compare chemically equilibrated and frozen-composition responses within the same Newtonian hydro-elastic framework. Frozen composition increases the effective bulk modulus and redistributes the strain throughout the inner crust rather than producing a simple global rescaling. F…

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astro-ph.IM

Magnetising the quokka code with fast, second-order accurate, error-correcting schemes for magnetohydrodynamics on GPUs

Neco Kriel, Elizabeth Cole-Kodikara, Benjamin Wibking, Mark R. Krumholz, Chong-Chong He, Anish Sarkar, Pak Shing Li

We implement a second-order accurate constrained transport (CT) magnetohydrodynamics (MHD) module with first-order flux correction in the open-source, adaptive mesh refinement (AMR), GPU-accelerated code quokka, supporting both ideal and resistive (constant Ohmic) regimes. For computing and averaging the electromotive forces (EMFs) at cell edges, the basis of any CT-MHD method, we experiment with a wide range of recent, state-of-the-art schemes, together with different reconstruction schemes. Al…

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astro-ph.IM

Magnetising the quokka code with fast, second-order accurate, error-correcting schemes for magnetohydrodynamics on GPUs

Neco Kriel, Elizabeth Cole-Kodikara, Benjamin Wibking, Mark R. Krumholz, Chong-Chong He, Anish Sarkar, Pak Shing Li

We implement a second-order accurate constrained transport (CT) magnetohydrodynamics (MHD) module with first-order flux correction in the open-source, adaptive mesh refinement (AMR), GPU-accelerated code quokka, supporting both ideal and resistive (constant Ohmic) regimes. For computing and averaging the electromotive forces (EMFs) at cell edges, the basis of any CT-MHD method, we experiment with a wide range of recent, state-of-the-art schemes, together with different reconstruction schemes. Al…

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astro-ph.EPastro-ph.IM

Fast and Furious: Long-term orbit integrations with collocation integrator Lobbie

Dmitrii E. Vavilov, Siegfried Eggl, Sarah Greenstreet

Efficient and accurate numerical integration methods are fundamental to studying long-term solar system dynamics, where numerical errors can accumulate over billions of orbital periods. In this work, we investigate the performance of our modification of Lobbie, a Lobatto collocation integrator for long-term simulations of the Solar System. We compare Lobbie against the widely used WHFast symplectic integrator and the high-order adaptive collocation integrator IAS15 implementations in the Rebound…

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astro-ph.IMeess.SP

Instrument-Level Validation of Upper Sideband Syntonization Concept

Volodymyr Kudriashov, Manuel Martin-Neira

Upper Sideband Syntonization (USBS) is a two-way frequency-transfer concept proposed by the European Space Agency for distributed space radio interferometric systems. Previous investigations validated the concept primarily through frequency-stability and phase-transfer measurements. This work demonstrates the first end-to-end instrument-level validation of the USBS concept through coherent W-band cross-correlation measurements and image reconstruction. A P=2 USBS breadboard was integrated with a…

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astro-ph.GA

The THRILS Factor: Investigating the properties of Little Red Dots (LRDs) at 3<z<6 with JWST/NIRSpec

Ananya Ganapathy, Rebecca L. Larson, Erini Lambrides, Guillermo Barro, Taylor A. Hutchison, Pablo Arrabal Haro, Anthony J. Taylor, Dale Kocevski et al.

JWST has uncovered a class of objects called LRDs, whose nature is still widely debated. In this work, we present a comprehensive spectroscopic analysis of nine LRDs in the Extended Groth Strip (EGS) field studied as part of THRILS and C3PO, both JWST Cycle 3 programs. These targets, photometrically selected based on their compact red appearance, are observed with deep spectroscopic exposures ($\geq8$ hours), enabling robust detections of broad Balmer lines, He I emission, and other spectral fea…

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

UX Men: Detached Eclipsing Binary as a Benchmark Candidate

Ganesh N. Pawar, Krzysztof G. Hełminiak, Nicola J. Miller, Frédéric Marcadon, Ayush Moharana, Tilaksingh B. Pawar, Anish Kalsi, Maciej Konacki et al.

We present ultra-precise fundamental parameters for the detached eclipsing binary UX Men based on 31 TESS sectors ($\sim$882 d) and radial velocities from HARPS, FEROS, CORALIE, and UCLES. The light curves were detrended for spot-induced variability and modelled independently with JKTEBOP and ALLESFITTER, while radial velocities were extracted via TODCOR and fitted with a Keplerian orbit. Spectral disentangling yielded individual component spectra analysed with iSpec to determine $T_{\rm eff}$ a…

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astro-ph.HEhep-exhep-ph

Low-Mass Magnetic Monopoles in the Galaxy: Simulations and Comparison with Ultra-High-Energy Cosmic-Ray Data

Ala'a AL-Zetoun, Igor Ostrovskiy, Peiwen Mi, Daniele Perri

Origin and composition of ultra-high energy cosmic rays are still uncertain, particularly the rare events exceeding the Greisen-Zatsepin-Kuzmin cutoff and whose apparent arrival directions point to the Local Void. This work is an in-depth investigation of the possibility that such cosmic rays contain low-mass magnetic monopoles predicted in several recent theoretical models. Using a custom extension to CRPropa, a state-of-the-art code for modeling cosmic ray propagation, monopoles are tracked in…

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astro-ph.GA

A Novel Approach to 3D Dust Mapping of the Central Molecular Zone

Arianna Vasini, Mattia C. Sormani, Jason L. Sanders, Adam Ginsburg, Cara Battersby, Francisco Nogueras-Lara, Rainer Schödel, Eva Deliporanidou et al.

The 3D distribution of dust and gas in the Milky Way's Central Molecular Zone (CMZ) is key to understanding gas inflows toward the Galactic Centre (GC), the process of star formation in this extreme environment, and the propagation of energetic cosmic rays originating from Sgr A*. However, while recent efforts have combined datasets in a Bayesian framework to estimate the near/far positions of individual molecular clouds in the CMZ, conflicts between different methodologies still remain and we a…

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astro-ph.SRastro-ph.IM

Solar Flare Prediction Using a Hybrid Convolutional Neural Network and Transformer Model

Mason Cao, Junwei Zhao

Solar flares are intense bursts of electromagnetic radiation that occur when stored magnetic energy in the Sun's atmosphere is suddenly released. They are categorized into five classes -- from least to most powerful: A, B, C, M, and X -- with each successive class representing a ten-fold increase in energy output. The electromagnetic radiation emitted by the stronger classes (C, M, and X) is capable of causing significant disruptions to communication systems, satellites, and power grids on Earth…

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physics.opticsastro-ph.IMquant-ph

New Method for Path-length Equalization of Long Single-mode Fibers for Interferometry

M. Anderson, J. D. Monnier, K. Ozdowy, J. Woillez, G. Perrin

The ability to use single mode (SM) fibers for beam transport in optical interferometry offers practical advantages over conventional long vacuum pipes. One challenge facing fiber transport is maintaining constant differential path length in an environment where environmental thermal variations can lead to cm-level variations from day to night. We have fabricated three composite cables of length 470 m, each containing 4 copper wires and 3 SM fibers that operate at the astronomical H band (1500-1…

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