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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.EP

Inversion Framework of Internal Mass Distribution Parameters of Asteroid Apophis from Dynamical Observations

Yiting Li, Chenyang Huang, Yang Yu, Shengping Gong, He Zhang

The detection of the internal mass distribution of asteroids is of great significance for understanding their origin, evolution, and mission planning for exploration. Previous approaches rely on indirect density estimates or close-range spacecraft gravity inversion, which have limited applicability. This paper presents a proof-of-concept framework to infer the internal mass properties of asteroid (99942) Apophis during its close Earth flyby in 2029 using dynamical observations collected during t…

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astro-ph.SRastro-ph.GAastro-ph.HE

On the Origin of a Dusty Circumstellar Medium around Red Supergiants

Das Sujit, Arkaprabha Sarangi, Sutirtha Sengupta

Red supergiant (RSG) stars are widely recognized as significant sources of dust, enriching the interstellar medium. However, the physical conditions that regulate dust nucleation in their winds remain poorly constrained. We investigate the formation of molecules and dust in RSG and explore how enhanced mass loss can produce a dense, dust-rich circumstellar medium (CSM) before core collapse. We couple time-dependent mass loss with non-equilibrium chemistry to model the formation of molecules and…

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astro-ph.GA

Deep VISTA observations of the Magellanic Clouds (VMCDeep)

M. -R. L. Cioni, A. O. Omkumar, N. J. G. Cross, F. Cusano, F. Dresbach, F. Ficara, F. Niederhofer, J. M. Oliveira et al.

The central regions of galaxies challenge observers with a high density of stars, gas and dust. The LMC hosts a dense stellar bar whereas the SMC hosts a dense core, which have eluded even the most sensitive large-scale wide-field surveys of individual stars from the ground and from space. This work describes deep imaging observations obtained with VISTA of the inner regions of the Clouds. They were obtained to resolve stars fainter than the red clump, that due to crowding were missed in previou…

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astro-ph.IM

JWST telemetry combined with active coronagraphy: raw contrast predictions for exoplanet imaging with the Habitable Worlds Observatory

Raphaël Pourcelot, Laurent A. Pueyo, Emiel H. Por, Marshall D. Perrin, Iva Laginja, Bryony Nickson, Sarah Steiger, Rémi Soummer et al.

We provide a quantification of the technological gap between the James Webb Space Telescope (JWST) and the Habitable Worlds Observatory (HWO) for the goal of exo-Earth imaging around Sun-like stars at the $10^{-10}$ raw contrast level. We use JWST's in-flight telemetry of the primary segmented mirror to simulate a JWST-like telescope equipped with a modern coronagraph instrument, inspired by the Roman Space Telescope (RST) Coronagraphic Instrument (CGI), featuring an Apodized Pupil Lyot Coronagr…

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physics.space-phastro-ph.EPastro-ph.SRphysics.plasm-ph

Solar Magnetic Configuration Control over Radiation Belt Electrons

Ahmad Lalti, Jonathan Rae, Clare Watt, Stephanie Yardley, Savvas Raptis

Earth is surrounded by two highly dynamic concentric belts of particle radiation. The outer radiation belt exhibits coherent variability at solar-cycle, seasonal, and 27-day (Carrington) timescales. While the solar-cycle and Carrington variations have been attributed to the recurrence of coronal hole solar wind, the seasonal variation has long been explained by local geometric effects that modulate the solar wind-magnetosphere coupling. Here, we challenge this paradigm by showing that the period…

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astro-ph.IM

Correction of the influence of rolling shutter detectors on determining the velocity of meteors from video recordings

Lukáš Shrbený, Jiří Borovička, Pavel Spurný, Jan Mánek, Jan Fuchs

Modern video cameras use either global or rolling shutter to create individual video frames. In case of global shutter, the whole frames are exposed and read out at the same time. In case of rolling shutter, the exposure and readout proceed sequentially line by line. Such cameras are now commonly used for meteor observations. It is then necessary to perform a correction for this type of image reading in order to correctly and accurately determine the velocity of recorded meteors. We provide here…

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astro-ph.SR

Probing magnetic fields in stars: A 2D oscillation framework including rotation and magnetism

Antoine Fort, Rhita-Maria Ouazzani, Lucas Barrault, Louis Manchon, Ludovic Petitdemange

Understanding the role of internal magnetic fields in stars remains a major challenge for the description of angular momentum transport and stellar evolution. It is therefore essential to probe these magnetic fields within the star, and asteroseismology provides a powerful means to do so. In this work, we present a new implementation of the 2D oscillation code ( ), which incorporates the effects of both stellar rotation and magnetic fields. Adaptive Code of Oscillations towards Realistic modelin…

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astro-ph.IMphysics.ins-det

Development, Configuration and Performance Characterization of a Scalable BETA ASIC-Based Readout System for Multi-Channel SiPM Detectors

Giulio Lucchetta, Keerthana Rajan Lathika, Benjamin Nobre Hauptmann, Philipp Azzarello, Oscar Blanch, Juan Boix, Laia Cardiel, Arturo Castaño Gallardo et al.

We present the design, configuration, and performance characterization of a scalable readout system based on the BETA application-specific integrated circuit (ASIC), developed to meet stringent requirements on noise, linearity, dynamic range, and power consumption for multi-channel silicon photomultiplier (SiPM) detectors in spaceborne instrumentation. The readout electronics consists of modular interface boards (FIBs) hosting multiple BETA ASICs and controlled by a field-programmable gate array…

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astro-ph.SR

Search for magnetic fields in seven slowly rotating A stars

Pablo de Frutos Rull, Coralie Neiner, Jonathan Labadie-Bartz, Frédéric Royer, Richard Monier, Keegan Thomson-Paressant

A small fraction of A-type stars host strong fossil magnetic fields. Identifying them relies on indirect indicators such as chemical peculiarities, slow rotation, and rotational modulation, which are also shared by non-magnetic stars. Assessing their reliability is essential for future surveys. We magnetically characterise seven slowly rotating, chemically peculiar A-type stars selected through two complementary strategies. Three were selected from abundance analysis combined with potential intr…

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astro-ph.IMastro-ph.EP

The PLACID active coronagraphic imager instrument: commissioning status

Ruben Tandon, Lucas Marquis, Liurong Lin, Derya Öztürk Çetni, Axel Potier, Audrey Baur, Iljadin Manurung, Matthias Brändli et al.

The world's first adaptive stellar coronagraph, the Programmable Liquid-crystal Active Coronagraphic Imager for the 4-m DAG telescope (PLACID) uses a spatial light modulator operating from H- to Ks-band to dynamically adjust the focal-plane phase mask entirely in software. Positioned between the TROIA XAO system and the DIRAC infrared detector, PLACID was installed on the Nasmyth platform of the Turkish 4-m DAG telescope in 2025, followed by optical alignment and successful preliminary acceptanc…

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astro-ph.IM

Design and implementation of an SLM-driven coherent differential imaging scheme

L. Lin, L. Marquis, R. Tandon, J. Kühn

Direct imaging of exoplanets from the ground remains fundamentally limited by fast-evolving post-adaptive optics (AO) residual wavefront errors, and by quasi-static speckles arising from non-common path aberrations (NCPAs) downstream of the AO wavefront sensor. To first order, both sources of contrast degradation remain coherent with the stellar light, and recent studies have shown that coherent differential imaging (CDI) techniques can address their quasi-static and slowly evolving components.…

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physics.comp-phastro-ph.IMhep-ex

Editorial: Promoting Green Computing in High Energy Physics and Astrophysics

Vasiliki A. Mitsou, Andreas Redelbach, Eleni Vardoulaki

This research topic aims to explore and promote strategies for green computing in high-energy physics and astrophysics. The primary objectives include assessing current energy consumption patterns, identifying opportunities for resource optimization, and fostering cross-disciplinary collaborations to enhance sustainability. Key questions to be addressed include: What are the current energy demands in these fields? How can existing technologies be leveraged for more efficient resource usage? What…

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astro-ph.GA

A High Velocity SiO Jet from S255N SMA3

P. D. Klaassen, M. Reiter, Y. Zhang, K. E. I Tanaka, A. E. Guzman

We present ALMA Band 6 observations of the compact source SMA3 in the S255IR region, analysing both SiO (J = 5-4, 6-5) and CS (J = 5-4) emission to characterise the structure and kinematics of its outflow. The data reveal a highly collimated bipolar jet traced by SiO, reaching line-of-sight velocities of up to $\pm$60 km s$^{-1}$ and de-projected velocities of $\pm$~80 km s$^{-1}$, with a collimation ratio of ~4.7 over a spatial extent of ~5800 au. The inferred dynamical age is 343 yr. Position-…

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astro-ph.IMastro-ph.CO

The Canadian Galactic Emission Mapper: A New 8-10 GHz Telescope to Map the Polarization of the Northern Sky

Joshua MacEachern, Mandana Amiri, Charles L. Bennett, Guinevere Berg, Mark Halpern, Gary Hinshaw, Gordon Lacy, Thomas J. Rennie et al.

The Canadian Galactic Emission Mapper (CGEM) radio telescope is mapping polarized Galactic foregrounds from 8-10 GHz to aid in the search for B-modes in the Cosmic Microwave Background (CMB). Here we describe the design and early on-sky characterization of the CGEM optics. CGEM employs an on-axis, hat feed optical design that is a body of revolution (BOR) and exhibits excellent intrinsic polarization purity. We describe how we have optimized the optics with a novel framework that can directly mi…

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astro-ph.SR

On the theoretical instability strips of γ-Doradus stars including the effect of the metallicity and rotation

L. Fellay, M. -A. Dupret

Recent space missions such as Kepler have provided large-scale observations of the γ-Doradus instability strips (IS), which can be used to constrain models and explore their limitations. One persistent limitation is the prediction of the blue edge of the γ- Doradus IS, where a significant number of γ-Doradus stars are observed. Despite these observational advances, no systematic study has been undertaken to explore the effects of different physical processes on the γ-Doradus. Our aim is to syste…

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astro-ph.GA

Dissecting ultra-diffuse galaxies in the field

A. Vanzanella, K. Malek, Junais, E. Bernaud, A. Gargiulo, H. Thuruthipilly, K. Lisiecki, A. Pollo et al.

Context. Ultra-diffuse galaxies (UDGs) in the field are faint, diffuse systems that remain poorly represented in the literature due to the need for spectroscopic confirmation and the difficulty of obtaining high S/N emission line measurements. Aims. We present a spectroscopic study of 17 blue UDG candidates in the field using optical emission lines to confirm their diffuse nature and properties. Methods. We derived spectroscopic redshifts($z_{\rm spec}$) for our field UDG candidates. We then com…

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astro-ph.IMphysics.optics

Broadband heterodyne interferometry with a chirped femtosecond laser in the H-band

Félix Gudin, Nicolas Forget

Infrared heterodyne interferometry offers a scalable alternative to direct interferometry for long-baseline telescope arrays. However, at near-infrared wavelengths, its sensitivity is limited by the electronic detection bandwidth and shot noise from the optical reference. Parallel detection via spectral multiplexing has long been identified as a potential means to increase the signal-to-noise ratio of heterodyne interferometers. We propose a new heterodyne detection architecture based on highly…

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astro-ph.SR

Extremely Low Mass Ratio Contact Binaries. III. Photometric and Spectroscopic Investigations of Eleven Systems

Youmo Lai, Kai Li, Raul Michel Murillo, Difu Guo, Liheng Wang, Xiang Gao, Han-ning Zhang, Xing Gao et al.

We present photometric and spectroscopic investigations of 11 totally eclipsing contact binaries with mass ratios below 0.15, classifying them as extremely low mass ratio contact binaries. The ground-based multiband light curves were modeled with PHysics Of Eclipsing BinariEs to derive the photometric parameters of these systems. The TESS light curves of J011323 and J002747 show pronounced asymmetries and continuous variations. Markov Chain Monte Carlo modeling suggests that these variations are…

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astro-ph.SR

CoBiToM project. III. Physical characterisation of the potential merger candidates AL Lep, ASAS J082243+1927.0, and ZZ PsA

Sofia Palafouta, Kosmas D. Gazeas, Pasi Hakala, Stanislaw Zola, Athanasios Kafkas, Maria Garro

Contact binaries (CBs) are key systems for investigating the late evolutionary stages that may lead to stellar coalescence. Systems with an extremely low mass ratio and high fill-out factor are of particular interest as potential merger candidates and possible progenitors of luminous red novae. A combined photometric and spectroscopic study of the CB systems AL Lep, ASAS J082243+1927.0, and ZZ PsA is presented. The aim is to derive self-consistent orbital and physical parameters, assess their ev…

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astro-ph.HEgr-qc

Spherical Accretion onto Konoplya Zhidenko Black Holes: Sonic Point Analysis and Fluid Dynamics

M H Waheed, M Z A Moughal

We investigate the spherical accretion onto a static Konoplya Zhidenko black hole and examine how the deformation of the spacetime affects the dynamics of the accreting matter. By applying the conservation laws of particle number and energy-momentum, we formulate the accretion problem and derive the corresponding Hamiltonian describing the fluid motion. The critical points and sonic transitions are then analyzed for ultra stiff, ultra relativistic, radiation, and sub relativistic fluids. We stud…

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astro-ph.SR

A decade of radial-velocity monitoring of rho Leo: moment analysis and periodic variability

V. A. Checha, A. Aret, I. Kolka, T. Liimets, V. Mitrokhina, A. Kasikov, T. Eenmäe, S. P. D. Borthakur et al.

We investigate the origin of long-term spectroscopic and photometric variability in the blue supergiant rho Leo, with particular emphasis on distinguishing between intrinsic pulsations and variability induced by a possible companion. Our analysis is based on an 11.5-year spectroscopic time series obtained at Tartu Observatory, complemented by high-cadence, high-resolution spectroscopy from the Hertzsprung SONG telescope and space-based photometry from TESS. We studied line-profile variability us…

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gr-qcastro-ph.HE

Devoured by a Hairy Gargantua: Probing Massive Scalar Charges with Non-minimal Curvature Coupling with Extreme-Mass-Ratio Inspirals

Leif Lui, Adrian Ka-Wai Chung, Alejandro Torres-Orjuela

Ultralight scalar fields nonminimally coupled to curvature can endow rotating black holes with stationary hair and alter nearby orbits. Using recently constructed hairy black-hole spacetimes, we model the transition to plunge of an extreme-mass-ratio inspiral. For scalar masses $μM=0.01$ and $0.1$ and dimensionless curvature coupling $ζ=10^{-3},10^{-4}$, we find $\mathcal{O}(10)$ rad of gravitational-wave dephasing relative to general relativity over $\mathcal{O}(10^3)$ orbits. A multimode Fishe…

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astro-ph.HE

The Geometry of Ultra-Fast Outflows Probed by Soft X-ray Variability in PDS 456

Riki Sato, Kouichi Hagino, Toshiya Iwata, Ehud Behar, Valentina Braito, Chris Done, Misaki Mizumoto, James N. Reeves et al.

Constraining the location and geometry of ultra-fast outflows (UFOs) is essential for identifying where they are launched and how they are accelerated. We investigate the soft X-ray variability of the luminous quasar PDS 456 using simultaneous March 2024 observations with XRISM/Xtend and NuSTAR. A model-independent comparison between the flare and quiescent phases reveals spectral variability around 1 keV in the rest frame, while the hard X-ray spectral shape remains nearly unchanged. Broadband…

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gr-qcastro-ph.HEhep-th

Dynamical friction on black holes in scalar field environment

Adith Praveen, Dawood Kothawala

Astrophysical black holes exist within non-vacuum environments, and their motion through these environments generically result in a force on these black holes through processes such as dynamical friction and Bondi accretion. We explore these forces numerically for black holes moving through a complex scalar field of mass $m$ with constant acceleration $a$, while also revisiting the constant velocity case considered in the existing literature. The former is modeled by the C-metric, while we use P…

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astro-ph.EP

Cooling-regulated gas accretion onto gap-opening planets

Ayumu Kuwahara, Michiel Lambrechts, Minghao Zhang, Ruobing Dong, Hideko Nomura

Gas accretion onto forming planets controls the final masses of giant planets and provides observable signatures of ongoing formation. How this process depends on the cooling properties of these newly attracted gas remains poorly constrained. We present long-term, three-dimensional global hydrodynamical simulations to quantify gas accretion onto gap-opening planets in the mass range between 1 and 3 Jupiter masses. We systematically vary the cooling time, $β$, from near-isothermal ($β=10^{-2}$ in…

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astro-ph.HEgr-qcnucl-th

Hyperon bulk viscosity effects in neutron-star inspirals

Elena M. Kantor, Mikhail E. Gusakov, Kirill Y. Kraav

The paper revisits the role of hyperon bulk viscosity during neutron-star inspiral. We find that hyperon bulk viscosity exerts only a minor influence on the gravitational-wave phase, causing a phase shift of $\sim 10^{-3}\,\rm rad$. This shift is too small to be detected by existing gravitational-wave observatories, and it seems unlikely that next-generation detectors will be able to isolate this effect from other factors. However, our analysis indicates that hyperon bulk viscosity can significa…

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astro-ph.HEastro-ph.GA

From Inspiral to Expansion: The Wake-Driven Torque on Binary Black Holes in Gaseous Medium

Jixuan Yang, Lile Wang, Xinyu Li, Rixin Li

Binary black holes (BBHs) in gaseous medium, such as active galactic nucleus (AGN) disks, are important gravitational-wave sources, yet the gas-driven torque that governs their orbital evolution remains to be fully understood. Most existing studies of BBHs in gas often approximate the net torque as the sum of independent dynamical friction (DF) forces exerted on each black hole by its own wake, neglecting the mutual gravitational coupling between the two wakes. We perform three-dimensional hydro…

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astro-ph.HE

Rapid Variability and Broadband Spectral Modeling in the Flaring Activity of BL Lacertae

Xin Chang, Dingrong Xiong, Chenxu Liu, Rui Xue, Tingfeng Yi, Jia Zhang, Yu Pan, Xingzhu Zou et al.

We report a multi-wavelength study of two flaring episodes of the blazar BL Lacertae during MJD 60500-60800 (9 July 2024 - 5 May 2025). The source reached a daily-averaged $γ$-ray flux of $(1.03 \pm 0.05) \times 10^{-5} \, \mathrm{ph \, cm^{-2} \, s^{-1}}$ ($E > 100$ MeV) on MJD 60588 (5 October 2024). Using orbit-binned data from the Large Area Telescope (LAT) onboard the \textit{Fermi Gamma-ray Space Telescope}, we identify a minimum flux halving timescale of $τ= 1.33 \pm 0.29$ hr. This constr…

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astro-ph.GA

Dense Cores in the Vicinity of an HII Region

Ruofei Zhang, Xing Lu, Jingwen Wu, Sihan Jiao, Hauyu Baobab Liu, Guang-Xing Li, Roberto Galván-Madrid, Aiyuan Yang et al.

Massive stars strongly influence their surroundings through radiative and mechanical feedback, but its effects on dense gas structures at sub-pc scales remain poorly constrained. We investigate how feedback from a newly formed massive star affects dense cores in the filamentary molecular cloud IRAS 18530+0215. We analyze ALMA Band 6 observations of 1.3 mm dust continuum and DCN, N$_2$D$^+$, and $^{13}$CS line emission, together with VLA K-band continuum and NH$_3$ observations. Dense cores are i…

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astro-ph.EP

Modeling Carbon-Based Planets with MAGRATHEA

Robert Royer, David R. Rice, Jason H. Steffen

A planet's interior structure not only influences its habitability, but it also provides information about the planet's formation and history. In the quest to characterize the variety of planetary discoveries, the most common practice is to rely on our understanding of the Earth's differentiated interior structure, with an iron core and silicate mantle as a starting point. However, recent work by arXiv:2408.07761 [astro-ph.EP] shows that these assumptions may not be true for all planetary system…

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