研究動向

astro-ph.IMphysics.data-an2026年8月21日

NestyNet. III. Symbolic Regression from Analytic Neural Surrogates

Rodrigo Ibata, Wassim Tenachi, Foivos Diakogiannis, Neil Ibata, Anirudh Shankar

Many physical laws are simple only after the right representation, decomposition or internal coordinate has been found, but discovering that structure from data is combinatorially hard. This task is symbolic regression (SR), the search for closed-form expressions that fit data without assuming a fixed model class. Here we present NestyNet-SR. A neural surrogate with analytic derivatives is used to detect separability, recursively reducing multivariate problems to simpler neural atoms. These atom…

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astro-ph.GA2026年8月21日

The superclumps of the local Milky Way. Supercloud fragmentation and the sites of star formation

Lilly A. Kormann, João Alves, Emily L. Hunt

Using a Gaia-based 3D dust map of the solar neighborhood, we analyze the internal structure of the seven local superclouds. We identify quasi-periodic density enhancements along their spines, which we term "superclumps" and show that 73% of the known star-forming regions in the dust map volume can be associated with them. Across the six superclouds with more than one recovered superclump, the spacings are characteristic per cloud: $\sim$150-250 pc for the Split, Malpolon Cloud and Vela Ridge Clo…

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astro-ph.GAastro-ph.SR2026年8月21日

Gas-phase and Surface Chemistry in the Massive Star-Forming Region RCW\,120

K. V. Plakitina, M. S. Kirsanova, D. S. Wiebe, O. V. Kochina

We analysed broadband emission spectra of a dense molecular clump in RCW 120, obtained with the APEX telescope in the 200--260 GHz range, in order to investigate molecular formation pathways in regions of massive star formation at an early evolutionary stage. We examined the correlations between the molecular column densities derived under the LTE assumption. An excess of methanol was found in the southern part of the dense clump relative to its northern part, while the abundances of other molec…

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astro-ph.IM2026年8月21日

NAIR-APREXIS: Enabling photonics-based instruments for long-baseline interferometry and integral-field spectroscopy

L. Labadie, R. J. Harris, K. Madhav, A. Dinkelaker, K. Barjot, A. Benoît, N. J. Scott, N. Anugu et al.

The NAIR project -- Novel Astronomical Instrumentation based on photonic light Reformatting -- aims at advancing photonic technologies for infrared long-baseline interferometry and precision spectroscopy. The rapid development of astrophotonics over the past decade has opened new pathways for astronomical instrumentation with unprecedented capabilities. We present results from NAIR that demonstrate the potential of the ultrafast-laser inscription (ULI) technique for fabricating remapping devices…

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astro-ph.HEastro-ph.SR2026年8月21日

Nucleosynthesis in the Accretion-induced Collapse of magnetised, Rotating White Dwarfs

Laurenz Thümmler, Takami Kuroda, Masaru Shibata

Accretion-induced collapse (AIC) of a rotating oxygen-neon-magnesium white dwarf (WD) is an alternative channel of neutron-star formation, in which a mass-accreting star near the Chandrasekhar mass collapses instead of being disrupted thermonuclearly. If the progenitor WD is sufficiently magnetised, it can drive magnetorotational outflows analogous to those of magnetorotational supernovae and may serve as a site for rapid neutron-capture ($r$-process) nucleosynthesis. We post-process tracer part…

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nucl-thastro-ph.HEastro-ph.SR2026年8月21日

Neutron star matter with hyperons: Bayesian comparison of nucleonic and SU(6)/SU(3) hyperonic models

Athira S., Vishal Parmar, Monika Sinha, Ignazio Bombaci

We investigate neutron star matter with hyperons within a density-dependent relativistic mean-field framework using Bayesian inference, considering three composition scenarios: purely nucleonic matter, hyperonic matter under SU(6) flavor symmetry, and hyperonic matter under SU(3) symmetry with free vector-sector parameters. The analysis incorporates constraints from empirical nuclear matter properties, theoretical inputs at low densities, and multimessenger observations of neutron stars. We find…

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physics.ins-detastro-ph.IMhep-ex2026年8月21日

Ion Irradiation of GridPix Detector at Bonn Isochronous Cyclotron

Vladislavs Plesanovs, Hemanth Manikantan, Dennis Sauerland, Paolo Soffitta, Carlo Lefevre, Ettore Del Monte, Jochen Kaminski, Reinhard Beck et al.

The potential successor of the IXPE --- the EXPO or Enhanced X-ray Polarimetry Observatory will have a new X-ray polarimeter based on GridPix technology. To certify this detector for operation within the expected radiation environment conditions, the irradiation tests were performed at the Bonn Isochronous Cyclotron at HISKPabbreviation\footnote{ stands for Helmholtz-Institut für Strahlen- und Kernphysik or Helmholz Institute for Radiation and Nuclear Physics}, University of Bonn. Two beam modes…

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astro-ph.EPastro-ph.SR2026年8月21日

The impact of tidal locking on Earth-like planetary dynamos

J. P. Hidalgo, D. R. G Schleicher

We investigate how tidal locking affects the planetary dynamo and the magnetospheres of Earth-like planets orbiting the habitable zones of M dwarfs. We couple an empirical stellar wind model with two distinct planetary dynamo paradigms, direct rotational scaling and energy-flux scaling, using a Constant Time Lag (CTL) model to simulate continuous tidal spin-down until synchronization. We model two hypothetical planets based on a highly dissipative Modern Earth and a less dissipative, rapidly rot…

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astro-ph.HEhep-phnucl-th2026年8月21日

Hyperonic compact stars with vector portal dark matter

Prafulla K. Panda, Deepak Kumar, Hiranmaya Mishra, Sudhanwa Patra

The appearance of hyperons in the core of neutron stars generally softens the equation of state (EOS), posing a longstanding challenge to the existence of observed two-solar-mass compact stars. We investigate whether repulsive interactions mediated by a dark-sector vector portal can provide an additional source of high-density pressure and thereby modify the structure of hyperonic compact stars. The baryonic sector is described within the modified quark-meson coupling (MQMC) model, in which the…

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astro-ph.GAastro-ph.CO2026年8月21日

Ultra-Deep imaging of the starless galaxy candidate Cloud-9

Ignacio Trujillo, Ignacio Ruiz Cejudo, Sergio Guerra Arencibia, Mireia Montes

We report the non-detection of stellar light associated with the dark galaxy candidate Cloud-9. Ultra-deep imaging obtained with HiPERCAM at the Gran Telescopio Canarias (GTC) reaches surface-brightness limits of 31.4 and 31.0 mag/arcsec$^2$ in g and r, respectively, approximately ten times deeper than previous deep imaging of the region. No stellar emission is detected within the central 1'$\times$1' ($\sim$1.3$\times$1.3 kpc) region of Cloud-9. Assuming an old, metal-poor stellar population, t…

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astro-ph.SR2026年8月21日

The DIRECD coronal mass ejection direction catalog: three-dimensional propagation inferred from coronal dimmings

Shantanu Jain, Tatiana Podladchikova, Karin Dissauer, Astrid Veronig, Amaia Razquin

Coronal mass ejections (CMEs) are among the primary drivers of space weather disturbances at Earth, yet their early propagation in the low corona remains poorly constrained owing to occultation and projection effects inherent to coronagraph observations. Coronal dimmings offer an alternative diagnostic to infer CME propagation direction directly from the low corona. We present the DIRECD CME Direction Catalog, a unified dataset of three-dimensional CME propagation directions derived via the DIRE…

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astro-ph.IMastro-ph.HE2026年8月21日

EXPO: a quantum leap in fast, wide-band X-ray polarimetry for astrophysics

Paolo Soffitta, Sebastien Guillot, Ian Hutchinson, Fabio Muleri, Mark Pearce, Andrea Santangelo, Daniele Spiga, Ivan Agudo et al.

The Enhanced X-ray Polarimetry Observatory (EXPO) is a mission concept proposed to ESA as an M8 candidate, with a prospective launch in 2041. Building on the scientific success of IXPE, EXPO is designed to overcome its two main limitations, the narrow 2-8 keV energy band and the very slow repointing time, and to enable new scientific capabilities. A wide energy band and fast repointing are essential for investigating the hard X-ray emission of magnetars and black-hole binaries, particle accelera…

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astro-ph.HEphysics.atom-ph2026年8月21日

Excitation and Recombination Data for Nd I-V with Applications to Kilonovae

N. Ferguson, L. P. Mulholland, M. McCann, C. P. Ballance, M. G. O'Mullane

Neodymium (Nd), a key r-process element, significantly influences the opacity and emergent spectra of kilonovae resulting from neutron star mergers. We present new atomic data for the first five ionization stages of Neodymium, with emphasis on recombination rate coefficients and electron-impact excitation relevant to non-local thermodynamic equilibrium (non-LTE) modelling. Using the relativistic atomic structure code {\sc autostructure}, we compute energy levels, radiative and dielectronic recom…

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astro-ph.HE2026年8月21日

Pulse profiles of accreting neutron stars - A review of analysis methods, observations, and theoretical models

Katja Pottschmidt, Peter Kretschmar, Ekaterina Sokolova-Lapa, Elena Ambrosi, Ralf Ballhausen, Peter A. Becker, Katrin Berger, McKinley C. Brumback et al.

X-ray pulsars are highly magnetized ($B\sim 10^{12}$ G) neutron stars accreting from a donor star. Their characteristic X-ray emission arises from accreted material decelerated from relativistic velocities near the magnetic poles of the neutron star. As our line of sight onto the magnetic poles changes with the rotation of the neutron star, the X-rays are periodically modulated, resulting in X-ray pulsations. The shape of the pulse profiles depends on the physics of the interaction between the b…

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astro-ph.HE2026年8月21日

GRB 220101A: a most energetic $10^{54}$ erg long GRB triggered by two supernovae 3.5 seconds apart

R. Ruffini, Y. Aimuratov, L. M. Becerra, Chris L. Fryer, Liang Li, G. J. Mathews, M. T. Mirtorabi, R. Moradi et al.

GRB 220101A is a long GRB, with a total energy exceeding $10^{54}$ erg with a redshift $z = 4.61$ and one of the largest ever high-quality multi-wavelength observational coverage, from a large number of space-based and ground-based telescopes. We interpret this source in a doubly Binary driven peta nova (BdP-N) model. The progenitor is composed of a massive CO core of $\sim 10\,M_\odot$, highly magnetized with $B \sim 10^{6}$ G, associated to a neutron star (NS) and a white dwarf (WD) with orbit…

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astro-ph.IMastro-ph.EP2026年8月21日

Chang'e 7 Lunar Lander Optical Camera-Telescope: Optical Astronomy from the Moon

Quentin Andrew Parker, Partha Sarathi Pal, Junhao Chen, Meng Su, SeyedAbdolreza Sadjadi, Andreas Ritter, Andy C. T. Kong, Zhengjie Tian et al.

We report the design and manufacture of a new, lightweight, wide-field, optical camera-telescope on board the Chang'e 7 lunar mission (launched in August 2026 and due for lunar touchdown in late November 2026). The camera is capable of static, panchromatic imagery within a $420-696~nm$ optical wavelength range. The camera was designed and built under the small lunar astronomy observation station program of the Chinese National Space Agency (CNSA) as a collaboration between the International Luna…

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astro-ph.GA2026年8月21日

Pandora cluster Lensing, AGN, and Transient Exploration (PLATE) from JWST Multi-Epoch Imaging. I. Discovery of a type II supernova candidate in a spiral galaxy at $z=0.7$

Yuxuan Pang, Xin Wang, Ping Chen, Subo Dong, Hang Zhou, Shengzhe Wang, Qianqiao Zhou, Xunda Sun et al.

We report the discovery and multi-wavelength analysis of a $z\sim0.7$ transient PLATE-23a in the Abell 2744 field, as the first results of the Pandora Lensing, AGN, and Transient Exploration (PLATE) project. Using multi-epoch JWST NIRCam imaging spanning from 2022 to 2025, we detect PLATE-23a in 12 filters. Difference-imaging analysis reveals its rising and declining phases. The host galaxy of PLATE-23a is a barred spiral at $z=0.688$ with a stellar mass of $\sim 10^{10.4}M_{\odot}$ and a star f…

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astro-ph.IMastro-ph.GA2026年8月21日

Radio Galaxies detection and characterization using deep learning techniques

Sanjay Khatik, Rohit Sharma, Pankaj Jain

Future radio telescopes will generate data volumes that are increasingly difficult to analyse using traditional statistical methods, motivating the adoption of machine-learning techniques. In this work, we present YOLO-Chars (YOLO-based Detection and Characterisation of Radio Sources), a two-stage deep-learning framework for the automated detection and characterisation of radio galaxies in survey images. The framework is developed and evaluated using the Square Kilometre Array Science Data Chall…

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astro-ph.SR2026年8月21日

BSN: Light Curve Modeling and Orbital Period Analysis of the Contact Binaries OV Leo and V339 Leo

Razieh Aliakbari, Atila Poro, Raul Michel, Sabrina Baudart

We present a combined photometric and orbital period analysis of the contact binary systems OV Leo and V339 Leo using ground-based observations together with TESS photometry. The light curves were modeled with the BSN software through a Markov Chain Monte Carlo approach, providing physical estimates of the system parameters and their uncertainties. OV Leo is analyzed photometrically for the first time, while V339 Leo is reexamined using new observations and an updated modeling methodology. The l…

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astro-ph.HEgr-qc2026年8月21日

A Dark Matter Masquerade: Degeneracies in Black Hole and Accretion Inference from X-ray Reflection Measurements and Prospects for Compact Dark Matter Halo Constraints

Leif Lui, Zijian Zhang, Alejandro Torres-Orjuela

X-ray reflection spectroscopy is an established probe of black hole (BH) spin and accretion geometry, and many studies have examined its systematic uncertainties. In this work, we explore a possible environmental effect associated with compact dark matter (DM) halos. We adopt numerical BH-DM spacetimes and perform general-relativistic ray-tracing calculations to generate broadened Fe\, K$α$ line profiles. For the configurations studied here, compact DM halos shift the lines toward lower observed…

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astro-ph.HE2026年8月21日

Effects of Ambient Medium Profiles on the Evolution of Relativistic Magnetized Jets

Xufan Hu, Yosuke Mizuno

Relativistic radio-galaxy jets are conventionally divided into two morphological classes: FR~I and FR~II. Among them, FR~I jets have relatively low radio luminosities and edge-darkened morphologies, indicating they undergo substantial deceleration and disruption on sub-kiloparsec to kiloparsec scales, often developing a turbulent and plume-like morphology. Here, we investigate the evolution of relativistic magnetized jets in stratified ambient media using 2D and 3D relativistic magnetohydrodynam…

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astro-ph.EPastro-ph.IM2026年8月21日

Microwave Remote Sensing of Giant Planet Atmospheres: Considerations for Saturn and Uranus Orbiter Missions

Alex Akins, Mark Hofstadter

Microwave radiometer instruments are uniquely capable of studying volatile element abundances and heat/mass transport within the deep atmospheres of giant planets. The results of the Juno MWR experiment have challenged long-held assumptions regarding Jupiter's troposphere, and the inclusion of such an instrument on future missions to Saturn or the ice giants would similarly re-write our understanding of giant planet atmospheres. We present a high-level summary of the capabilities of microwave ra…

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astro-ph.IMastro-ph.GAcs.AIcs.LG2026年8月21日

Amplifying the imaging power of digital sky surveys with space telescopes data and generative AI

Sai Teja Erukude, Lior Shamir

While Digital sky surveys provide excellent throughput of image data and can cover a large footprint, their imaging power is normally inferior to that of space-based telescopes. Space-based telescopes, on the other hand, provide excellent imaging power and can image the deep Universe, but cannot provide the same throughput as advanced ground-based sky surveys. Here, we utilize generative AI to elevate the quality of galaxy images taken by ground-based telescopes to the level of details enabled b…

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astro-ph.EPastro-ph.IMeess.SYmath.OC2026年8月21日

Physics-Informed Bayesian Optimization Warm-Starts for Sequential Convex Programming in Asteroid Surface Hopping

Baran Ekşi, Tufan Kumbasar

Surface hopping is an attractive mobility mode for small-body exploration, but designing fuel-optimal hops on asteroid 433~Eros requires solving a nonconvex optimal control problem with an irregular polyhedral gravity field, thrust--mass coupling, and collision-avoidance constraints. We show that a physics-informed Bayesian Optimization (BO) warm-start---a Gaussian-process search over a single Bézier control point that requires no offline training---provides a more reliable initialization for Se…

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astro-ph.EP2026年8月21日

Accounting for Transit Timing Detectability: Biases in Planetary Radius and Orbital Period

Skylar D'Angiolillo, Daniel Fabrycky, Mariah G. MacDonald

Transit Timing Variations (TTVs) are deviations from the time an observer would expect to see an exoplanet transit its host star. In multi-planetary systems, significant TTVs may indicate the presence of another body in the system gravitationally interacting with the transiting exoplanet. T. Holczer et al. (2016) catalogs 2599 Kepler Objects of Interest (KOIs) and provides a statistical analysis of their TTVs for candidates that have transited at least seven times. However, this conservative lim…

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gr-qcastro-ph.IM2026年8月21日

Bayesian P-spline recovery of stochastic gravitational-wave backgrounds in LISA

Nazeela Aimen, Patricio Maturana-Russel, Avi Vajpeyi, Nelson Christensen, Renate Meyer

The detection of a stochastic gravitational-wave background (SGWB) is a primary science objective for the Laser Interferometer Space Antenna (LISA). However, extracting these signals is difficult because both the signal and the instrumental noise are stochastic and overlapping in the millihertz band. In this work, we present a Bayesian framework for the joint estimation of LISA noise and SGWB signals. Our approach models the LISA instrumental noise using flexible log-penalized splines, employing…

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astro-ph.SR2026年8月21日

Statistical Analysis of Minifilament Eruptions Using Full-disk H$α$ Blue-wing Observations at Big Bear Solar Observatory

Artin Khaleghi, Qin Li, Nengyi Huang, Jeongwoo Lee, Haimin Wang

This paper presents a comprehensive statistical analysis of minifilament eruptions (MFEs) using high-cadence full-disk H$α$ blue-wing observations from Big Bear Solar Observatory. Despite the recognized importance of MFEs for coronal dynamics and solar wind structuring, previous efforts were often limited by small sample sizes or restricted fields of view, leaving open questions about their global occurrence and characteristic properties. We developed an algorithm incorporating intensity thresho…

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astro-ph.GA2026年8月21日

Mapping the z>=5 SiIV Column Density Distribution onto the Galaxy Stellar Mass Function Using the Cumulative Absorption Cross Section

Kristian Finlator, Sam Patterson, Nora Nava, Ayanah Cason, Samir Kušmić, Ezra Huscher, Farhanul Hasan

Efforts to constrain directly the activity in low-mass galaxies confront sensitivity limits even in the JWST era. Metal absorbers offer a complementary probe and are easier to detect, but leveraging them requires a known relationship between absorber strength and host mass. To this end, many studies assume a simple monotonic relationship between absorber strength and host mass. This ansatz ignores evidence that galaxies at fixed luminosity host absorbers spanning a variety of strengths. We addre…

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cs.PLastro-ph.IMastro-ph.SRcs.CEcs.DC2026年8月21日

Portability of Fortran's 'do concurrent' on GPUs II

Ronald M. Caplan, Miko M. Stulajter, Jon A. Linker, Jeff Larkin, Nikolaos Tselepidis, Harald Servat, Shiquan Su, Giacomo Capodaglio et al.

There continues to be growing interest in using standard language constructs for parallel and accelerated HPC computing, avoiding the need for (sometimes vendor-specific) external APIs. For Fortran applications, language features such as 'do concurrent' loops open the door for compilers to implement multi-threaded, GPU-accelerated, and even distributed multi-node code with only the standard language. Here, we explore the current status of using 'do concurrent' for GPU-accelerated Fortran applica…

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astro-ph.EP2026年8月21日

JWST Spatial-Spectral Mapping of Green Comet C/2022 E3 (ZTF)

Stefanie N. Milam, Nathan X. Roth, Geronimo L. Villanueva, Dominique Bockelee-Morvan, Jacques Crovisier, David E. Harker, Michael S. P. Kelley, Kiernan D. Foster et al.

We report a survey of molecular emission from cometary volatiles using the James Webb Space Telescope (JWST) toward Oort cloud comet C/2022 E3 (ZTF) carried out on UT 2023 February 28 and March 1 at a heliocentric distance (rH) of 1.33 au. These measurements of H2O, HCN, CH3OH, C2H6, CH4, CO, CO2, 13CO2, and OCS sampled post-perihelion molecular chemistry in C/2022 E3. A suite of near to mid-infrared OH (prompt emission) transitions were also detected. This work presents nucleus-centered spectra…

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