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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。

gr-qcastro-ph.HEastro-ph.IMstat.AP

Bayesian nonparametric estimation of correlated gravitational wave detector network noise using matrix-gamma process priors

Yixuan Liu, Renate Meyer, Nelson Christensen, Jeung Eun Lee, Jianan Liu, Patricio Maturana-Russel, Avi Vajpeyi

This paper addresses the important problem of estimating the noise spectral density of next-generation gravitational-wave detectors, such as LISA and the Einstein Telescope (ET), where cross-channel correlations must be accounted for to avoid biased parameter estimation of gravitational-wave signals. Unlike approaches that estimate test-mass and optical-metrology-system noise separately at the single-link level and then map them to the Time-Delay Interferometry (TDI) channels through known trans…

astro-ph.GAastro-ph.CO

An Enhanced Catalog of Gaia DR3 Galaxy Candidates with Spectroscopic and Machine-Learning Photometric Redshifts

Junghyun Hwang, Ho Seong Hwang

We present an updated galaxy catalog based on the Gaia Data Release 3 (DR3) Galaxy Candidates table, augmented with both spectroscopic and machine-learning based photometric redshift estimates. While the original catalog of Gaia DR3 galaxy candidates provides an unprecedented all-sky sample of extragalactic sources, its scientific utility for extragalactic and cosmological studies has been limited by the absence of redshift information and by its relatively low source purity. To address these li…

astro-ph.IM

Impact of microlens shape on the performance of Laser Guide Star wavefront sensors for ELT-class telescopes

Paul Rouquette, Benoit Neichel, Cédric Taisir Heritierc, Pierre Jouve, Anne Costille, Kjetil Dohlen, Thierry Fusco

Laser Guide Star (LGS) adaptive optics systems on extremely large telescopes (ELTs) rely on Shack-Hartmann wavefront sensors (SHWFS) equipped with large-format microlens arrays. Manufacturing imperfections in the microlens surface profile degrade spot quality and reduce centroiding accuracy, yet this effect is rarely quantified in the context of full AO system performance. This paper presents a comprehensive characterization of the impact of microlens shape on LGS wavefront sensing, using the MO…

astro-ph.IM

Towards an Extended VLTI: Turbulence Characterization for Kilometer-Scale Optical Links at Paranal

B. Neichel, T. Pichon, G. Bourdarot, D. Perez, E. Vera, V. Chambouleyron, T. Fuscod, C. -T. Heritier et al.

Future extensions of the VLTI aim to push infrared interferometry toward kilometer scale baselines, enabling angular resolutions of a few tens of micro-arcseconds. A first step would couple a new telescope on the VISTA platform to the existing VLTI infrastructure, creating a 1.4 km baseline at Paranal. Among the possible beam-transport solutions, direct free-space transmission with adaptive-optics (AO) pre-compensation, inspired by Free-Space Optical (FSO) communications, offers an attractive co…

astro-ph.IMastro-ph.COastro-ph.EPastro-ph.GAastro-ph.SR

HARMONI@ELT: instrument design, performance, and science capabilities

B. Neichel, J. Dunlop, S. Chittick, D. Le Mignant, M. Swinbank, A. de Lorenzo-Caceres, W. Taylor, M. Tecza et al.

HARMONI is the integral field spectrograph for the Extremely Large Telescope (ELT). Designed as the primary workhorse near-infrared spectrograph of the ELT, it will deliver spatially resolved spectroscopy at diffraction-limited angular resolution over the wavelength range 0.75 - 2.4 um, addressing science questions ranging from the characterization of exoplanet atmospheres to the internal kinematics of galaxies at the epoch of reionization. This paper presents the current status of the HARMONI p…

astro-ph.SRastro-ph.IM

Probing the Physics of the Solar Corona with High-Resolution Observations using SKA-Mid

Mark C. M. Cheung, John S. Morgan, Rohit Sharma, Sven Wedemeyer, Gregory Fleishman, Matthias Rempel

We examine the capability of the SKA-Mid telescope for probing solar coronal structure and evolution. Using radiative magnetohydrodynamics simulations of a solar flare, we synthesise radio emission in bands available to SKA-Mid. SKA-Mid observations would provide important constraints on plasma processes that are important to diverse astrophysical environments, including flares/eruptions, magnetic reconnection, particle acceleration, and gyro-emission processes. Observations with the AA4 configu…

physics.opticsastro-ph.IMphysics.ins-det

Addressing rotational motion on gravitational waves detectors

Chiara Di Fronzo, Jian Liu

The rotational components of Earth's seismic motion are one of the major contributions to limit the sensitivity of terrestrial gravitational-wave detectors at frequencies below 10 Hz. The fundamental challenges lie in understanding the angular degrees of freedom of seismic motion and how they can be accurately measured. These are both crucial steps for developing an adequate control system to suppress seismic motion and maintaining resonance in the detector cavities. This review shows why the ro…

astro-ph.SR

Observations of a Solar Jet Triggered by Reconnection between Super-penumbral Fibrils and a Mini-filament

Liheng Yang, Xiaoli Yan, Qingmin Zhang, Zhike Xue, Zhe Xu, Jincheng Wang, Fangyu Xu, Yian Zhou et al.

Coronal jets are highly dynamic phenomena in the solar atmosphere, yet their driving mechanisms remain an active topic of investigation. In this paper, we report a coronal jet triggered by the interaction between super-penumbral fibrils and a mini-filament, based on coordinated observations from the New Vacuum Solar Telescope (NVST), the Chinese H$α$ Solar Explorer (CHASE), and the Solar Dynamics Observatory (SDO). The fibrils were anchored between the negative-polarity region of a sunspot and a…

gr-qcastro-ph.HE

Dendro-GR at high mass ratios with high spins

William K. Black, David W. Neilsen, Eric W. Hirschmann, David F. Van Komen

The Laser Interferometer Space Antenna (LISA) launches in less than a decade; it will detect spinning high-mass-ratio binary black hole inspirals annually, alongside other third-generation gravitational wave detectors. High-mass-ratio systems occupy a regime where numerical-relativity simulations remain computationally expensive and technically demanding, especially with high spins at precessing orientations. This portion of parameter space thus remains undersampled, leading to significant bias…

astro-ph.SR

Three-dimensional Magnetic Field Structure of a Quiet-Sun Region Revealed by Sunrise III/SCIP

Masahito Kubo, Yukio Katsukawa, Yusuke Kawabata, Takayoshi Oba, Hirohisa Hara, Toshifumi Shimizu, Ryohtaroh T. Ishikawa, Takuma Matsumoto et al.

The balloon-borne stratospheric solar observatory Sunrise III successfully completed 6.5 days of observations in July 2024. One of its focal-plane instruments, the Sunrise Chromospheric Infrared spectroPolarimeter (SCIP), is a slit-scanning spectropolarimeter that simultaneously measures full Stokes profiles of multiple spectral lines in the 850 nm and 770 nm bands. SCIP obtained an unprecedented data set of a quiet-sun region near disk center, covering a $58'' \times 58''$ field of view. With a…

astro-ph.SR

Three-dimensional Magnetic Field Structure of a Quiet-Sun Region Revealed by Sunrise III/SCIP

Masahito Kubo, Yukio Katsukawa, Yusuke Kawabata, Takayoshi Oba, Hirohisa Hara, Toshifumi Shimizu, Ryohtaroh T. Ishikawa, Takuma Matsumoto et al.

The balloon-borne stratospheric solar observatory Sunrise III successfully completed 6.5 days of observations in July 2024. One of its focal-plane instruments, the Sunrise Chromospheric Infrared spectroPolarimeter (SCIP), is a slit-scanning spectropolarimeter that simultaneously measures full Stokes profiles of multiple spectral lines in the 850 nm and 770 nm bands. SCIP obtained an unprecedented data set of a quiet-sun region near disk center, covering a $58'' \times 58''$ field of view. With a…

astro-ph.GAastro-ph.SR

Stellar Population Astrophysics (SPA) with the TNG. Beyond the iron peak: Galactic evolution of molybdenum, ruthenium and zirconium through open clusters

Natalia Alvarez-Baena, Valentina D'Orazi, Christopher Sneden, Athanasios Psaltis, Frédéric Thévenin, Angela Bragaglia, Tamara Mishenina, Shilpa Bijavara Seshashayana et al.

Context: Open clusters serve as key laboratories for studying the chemical evolution of the Milky Way. In particular, leveraging these coeval groups of stars to study elements beyond the iron peak provides insights into heavy-element nucleosynthesis, whose origins remain uncertain. Aims: This work aims to determine the Mo, Ru, and Zr abundances for 81 stars across 30 open clusters. We compare these new chemical patterns with those of key reference elements (Y, Sr, Eu), which were previously deri…

astro-ph.EP

Dynamical evolution and surface accretion of DART impact ejecta in the (65803) Didymos system

Xiaoyu Fu, Nicolo Stronati, Stefania Soldini, Fabio Ferrari, Carmine Giordano, Paolo Panicucci, Alessandro Rossi, Adriano Campo Bagatin et al.

The DART spacecraft impacted Dimorphos, the small moonlet of Didymos binary system, on 26 September 2022. The impact ejected dust, fragments, and boulders into the near-binary environment. In November 2026, ESA's Hera mission is expected to arrive at the binary system to characterise both asteroids and investigate the post-impact consequences in detail. In this research, we aim to investigate the dynamical evolution of DART-generated impact ejecta and to quantify their surface accretion patterns…

astro-ph.SRastro-ph.GA

Ultracool and Brown Dwarf Candidates Identified via CatWISE-2MASS-Gaia DR3

Daniel Majaess, Dante Minniti, Matias Gomez, Roberto K. Saito, Maria G. Navarro

Ultracool and brown dwarf candidates ($d_{\odot}\lesssim 125$ pc, $|b|>8^{\circ}$) were identified via multiband and astrometric data from CatWISE ($W_1W_2$), 2MASS ($JHK_s$), and Gaia DR3 ($G$, $G_{RP}$, $π$, $μ_α$, $μ_δ$). $N\approx 11.8 \times 10^3$ candidates emerged once simultaneously constrained by color and absolute magnitude criteria (e.g., $G-W_2 \ge 1.75(G-J)-2.25$), whereby $\simeq 350$ sources are absent from the Gaia Ultracool Dwarf (UCD) catalog. Spectral types were approximated u…

astro-ph.GA

Automated Computer Vision Cluster Identification in the Fireworks Galaxy

Debby Tran, Benjamin F. Williams, Emily M. Levesque, Tobin M. Wainer, Emerson Bowles, Bo-Eun Choi, L. Clifton Johnson, Anil C. Seth et al.

We present the integrated photometry, radii, and spatial distribution of young ($\leq$ 25 Myr) star cluster candidates in NGC 6946. NGC 6946, also known as the Fireworks Galaxy, is a highly star-forming galaxy with numerous young massive clusters. We have developed a modified computer vision algorithm using photometry from images taken with Hubble Space Telescope (HST) Wide Field Camera 3 Ultraviolet channel (WFC3/UVIS) F275W and F336W filters to identify and outline candidate clusters. We descr…

astro-ph.GA

The evolution of galaxy dust scaling relations in the COLIBRE simulations

Aswin P. Vijayan, James W. Trayford, Joop Schaye, Sylvia Ploeckinger, Andrea Gebek, Nick Andreadis, Maarten Baes, Alejandro Benítez-Llambay et al.

We present dust scaling relations across cosmic time ($0 \le z \le 15$) for galaxies in the COLIBRE cosmological simulations. COLIBRE self-consistently tracks dust production, growth, destruction, and grain size evolution within a multiphase interstellar medium. Using volumes up to $(400\, {\rm cMpc})^3$ at three mass resolutions ($10^{5}-10^7$ M$_{\odot}$), we predict the dust mass function, cosmic dust mass density, and key dust scaling relations (dust-to-gas ratio, dust-to-metal ratio, grain…

astro-ph.HEastro-ph.IM

QuickGWecc: Fast Bayesian pipeline for searching eccentric binaries in pulsar timing array data

Lankeswar Dey, Bence Bécsy, Abhimanyu Susobhanan, Maria Charisi

Recent pulsar timing array (PTA) results have provided evidence for the presence of a nanohertz gravitational wave (GW) background, most likely originating from a population of supermassive black hole binaries (SMBHBs). The next major milestone is the detection of continuous GWs (CGWs) from an individual SMBHB and the identification of its electromagnetic counterpart. Typically, searches for CGWs in PTA data assume binaries in circular orbits. However, theoretical studies indicate that binaries…

astro-ph.SR

Long-Slit Spectroscopy Of Herbig-Haro Outflow System, Associated With IRAS 01166+6635

T. A. Movsessian, T. Yu. Magakian, A. V. Moiseev

We present long-slit spectroscopic observations of the outflow associated with an infrared source IRAS 01166+6635, conducted with the 6-m telescope of the Special Astrophysical Observatory using the SCORPIO-2 focal reducer. The structure of the flow as investigated in detail, its position-velocity diagrams are constructed. The electron densities of the several knots in the outflow were estimated, revealing a decrease in its density with increasing distance from the driving source.

astro-ph.SRastro-ph.IM

Automated Solar Radio Burst Detection Using Deep Learning on Augmented e-Callisto Data

Vincenzo Timmel, André Csillaghy, Christian Monstein

Solar radio bursts are signatures of energetic events associated with solar flares and coronal mass ejections and can interfere with terrestrial and space-based communication systems. Real-time automatic burst monitoring enables early warnings tens of minutes to hours before associated particles reach Earth and provides the basis for long-term statistical studies. The e-Callisto network is a worldwide system of solar radio spectrometers providing continuous observations, with its instruments col…

astro-ph.COastro-ph.GA

Anisotropic Secondary Bias of Dark Matter Haloes in a $Λ$CDM Universe

Qinglin Ma, Cheng Li

Secondary bias is the dependence of halo clustering on properties beyond halo mass. Using the $z=0$ TNG300-1-Dark simulation, we study anisotropic secondary bias (ASB): the variation of secondary bias with direction relative to the halo major axis. We first use ordinary, orientation-averaged secondary bias (OSB) as a baseline to compare three environmental manifestations: halo-environment alignment, outer matter anisotropy, and tidal anisotropy. Matching tidal anisotropy suppresses much of the O…

astro-ph.IMastro-ph.GAastro-ph.HEastro-ph.SR

The IMF package: a toolkit implementing mass functions and statistical tools to analyze them

Theo Richardson, Adam Ginsburg, Sergey Koposov

Mass functions are used in all areas of astrophysics. The stellar initial mass function (IMF), in particular, plays a central role in modeling stellar populations in galaxies. However, few dedicated tools for working directly with the IMF and its precursor functions are widely available. We present the $\texttt{imf}$ package, a Python library integrated into the wider scientific Python ecosystem that implements common and variant forms of mass functions, especially the IMF and its pre- and proto…

astro-ph.SR

Understanding the Travel-time Asymmetry of Acoustic Waves in Sunspots With Time-distance Helioseismology

Haiyu Li, Tobías Felipe, Elena Khomenko, Hui Tian, Paul Rajaguru, Yuhang Gao

Mapping the subsurface structure and flow field of sunspots has been a challenging task for helioseismology. In this work, we investigate the propagation of acoustic waves in a sunspot in NOAA active region 11312 using time-distance helioseismology. Travel times of waves traveling into and out of the sunspot are measured as functions of travel distance and azimuthal angle relative to the local radial direction. The same time-distance analysis is also applied to a simulated data based on a magnet…

astro-ph.IM

Advancing X-Ray Camera Front-End Electronics Architecture through the AXIS-TAP Technology Platform

Jill Juneau, Declan O'Neill, Peter Orel, Eric Miller, Sven Herrmann, Gregory Prigozhin, Robert Goeke, Elio Angile et al.

Advancing time-domain soft X-ray astronomy demands focal plane readout electronics capable of high-speed digitization with low noise while maintaining spectral fidelity across multiple detector channels. The Advanced X-ray Imaging Satellite (AXIS), a NASA Probe-class mission concept, provided the driving requirements and heritage for developing a generalized high-speed (>=5 fps) camera Front-End Electronics (FEE) architecture applicable to future soft X-ray missions. The FEE architecture defines…

astro-ph.HEastro-ph.GAhep-ex

High-energy neutrino emission from the Milky Way

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

The Milky Way hosts astrophysical objects that accelerate cosmic rays to energies beyond the reach of terrestrial particle accelerators. It remains a longstanding goal to locate the sites of these powerful Galactic engines and understand how cosmic rays propagate through the Galaxy, leading to the production of high-energy neutrinos. In this paper, we combine event morphologies characteristic of all three neutrino flavours and apply recent improvements in ice modelling, calibration and reconstru…

astro-ph.EP

Volcanic Satellites and Ion Escape in the Magnetospheres of Ultra-Cool and Brown Dwarf Stars

A. F. Lanza, A. V. Oza

Radio emissions at $\sim$ GHz frequencies of ultra-cool dwarf and brown dwarf stars suggest the presence of radiation belts not unlike Jupiter's. We investigate the possibility the inferred magnetospheric plasma at the primary star is sourced by an active planet or via ion escape modeled as a weak ionospheric outflow. We consider indirect methods to estimate the magnetospheric plasma mass flow from auroral radio emission and apply them to the ultra-cool dwarf LSR J1835+3259. We find that an iono…

astro-ph.IM

CNN-Based Reanalysis of Optical Turbulence at the Canary Islands Observatories (OCAN)

Airam Salas, Begoña García-Lorenzo, Julio A. Castro-Almazán, Gelys Trancho

Atmospheric optical turbulence, caused by refractive-index fluctuations driven by wind and temperature inhomogeneities, is the primary source of image degradation in ground-based telescopes. Its vertical distribution, described by the refractive-index structure constant (Cn2(h)), determines essential parameters such as seeing, isoplanatic angle, and coherence time, which characterize astronomical sites and are also crucial for the design and performance of high-resolution instruments. The Observ…

astro-ph.EP

Orbital Motion and History of Sungrazing Comet C/2026 A1 (MAPS)

Zdenek Sekanina, Malgorzata Krolikowska

We report results of our extensive computations of the orbital motion of comet C/2026 A1, including its integration back to the fourth century and parallel integration of 1000 virtual clones. We focus on this Kreutz sungrazer's apparent association with the daylight comets in AD 363, recorded by Ammianus Marcellinus. We show that the derived time of the previous perihelion is strongly affected by erratic outgassing-driven nongravitational forces and depends on the chosen set of observations. We…

astro-ph.GAastro-ph.SR

The influence of dust destruction on gas cooling

S. A. Drozdov, M. P. Yudkevich

The observed dust abundance in the early Universe significantly exceeds the predictions of models assuming its efficient destruction at supernova shock wave fronts. We investigate the effect of dust on gas cooling behind the shock wave front, taking into account both dust cooling and thermal sputtering of dust grains for various interstellar dust models. Isochoric cooling of a gas element is considered for various initial temperatures (from $3\cdot 10^{5}$ K to $3\cdot 10^{7}$ K) and metalliciti…

astro-ph.SRastro-ph.HE

A systematic assessment of the short-term X-ray behaviour of the $γ$ Cas analogues

Robbie Webbe, Yaël Nazé, N. A. Webb

Context. Overall, $γ$ Cas analogues represent a class of OBe stars displaying bright and hard X-ray emission. This emission was recently determined to be the result of accretion onto a companion white dwarf (WD), which might possibly be a magnetic WD. Aims. We present a systematic review of the properties of $γ$ Cas analogues on short-term (kilosecond, ks) scales to further investigate the nature of the X-ray source. In particular, the presence of periodicities could be associated with the rotat…

cs.CLastro-ph.COastro-ph.IMcs.HCgr-qc

AI's Capability in Assisting Scientific Research in Physics, Astrophysics, and Cosmology II: Project Planning and Proposal Evaluation

Jia Liu, Veena Krishnaraj, Kateryna Vovk, Kosuke Aizawa, Adrian E. Bayer, Linda Blot, Jessica Cowell, Suyog Garg et al.

We investigate how well large language models (LLMs) can assist scientific project planning and proposal evaluation. One-page project plans were independently generated for eight expert-conceived research projects in physics, astrophysics, and cosmology by human researchers and three contemporary LLMs (ChatGPT, Claude, and DeepSeek; mid-2025 models, used with their default tool access). The resulting 32 proposals were blindly evaluated by four human reviewers and two newer frontier LLMs (Claude…