研究動向

astro-ph.GA2026年8月3日

The TNG50-SKIRT Atlas: Spatially resolved synthetic galaxies from the ultraviolet to the submillimetre (DR2)

Maarten Baes, Paul Vauterin, Abdurro'uf, Nick Andreadis, Thiago Bueno-Dalpiaz, Sena Bokona Tulu, Peter Camps, Abdissa Tassama Emana et al.

We present the second data release (DR2) of the TNG50-SKIRT Atlas (TSA), a library of synthetic, spatially resolved galaxy observables. The atlas is constructed by post-processing a stellar-mass-complete ($10^{9.8}~{\text{M}}_\odot < M_\star < 10^{12}~{\text{M}}_\odot$) sample of 1154 $z=0$ galaxies from the TNG50 cosmological hydrodynamical simulation with the Monte Carlo radiative transfer code SKIRT. Compared to the first release, TSA DR2 extends the wavelength coverage from the ultraviolet t…

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astro-ph.GA2026年8月3日

Projection Effects in Merger Dating for Illustris TNG Shell Galaxies

Tuğba Erol, Mustafa Kürşad Yıldız, Ivana Ebrová, Michal Bílek

Stellar shells are low-surface-brightness structures that typically appear as concentric arcs. They are observed in many giant elliptical and lenticular galaxies, as well as in some spiral and dwarf galaxies. They presumably result from minor and intermediate close-to-radial mergers of galaxies. An essential factor in determining the merger time are the distances of shells from the centre of the galaxy. Consequently, estimates of the merger time can be significantly affected if some shells remai…

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physics.ins-detastro-ph.IMhep-ex2026年8月3日

Spectroscopic study of argon electroluminescence light with a wavelength-sensitive particle detector

R. Santorelli, V. Pesudo Fortes, G. Vera Díaz, C. K. Guérard, R. López Manzano, L. Luzzi, J. Martínez Morales, L. Romero et al.

We present a spectroscopic study of argon electroluminescence (EL) light in a gaseous time projection chamber (TPC). Using a compact detector equipped with photomultiplier tubes with different spectral sensitivities, we measure the light emission in two nominal wavelength regions, approximately [110, 160] nm and [160, 650] nm, at different gas pressures. In addition to the well-known 128 nm emission of the second continuum, significant emission is observed in the [160, 650] nm band, with a promp…

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astro-ph.SR2026年8月3日

Alfvénic Motions in a Stratified Open Flux Tube: Transition from Propagating to Locally Standing Motions and Implications for the Kelvin-Helmholtz Instability

Mingzhe Guo, Bo Li, Yuhang Gao, Yao Chen

Standing transverse waves in closed coronal structures have been widely studied as a possible route to energy dissipation, with resonant absorption transferring kink wave energy to localized Alfvénic motions and the Kelvin-Helmholtz instability (KHI) accelerating the formation of small dissipative scales. However, it remains unclear whether the same mechanism applies to the open corona, given the long-standing consensus that the KHI tends to be prohibited for propagating Alfvénic waves. Within t…

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astro-ph.GA2026年8月3日

NEXUS: Spectral Variability of Little Red Dots and Blue Active Galactic Nuclei at $2 \lesssim z \lesssim 6$

Zachary Stone, Yue Shen, Ming-Yang Zhuang, Junyao Li, Zhiwei Pan, Jenny E. Greene, Feige Wang

We present spectral measurements for 17 Little Red Dots (LRDs) and 14 blue broad-line active galactic nuclei (AGNs) at $2\lesssim z \lesssim 6$ using multi-epoch JWST NIRSpec MSA spectra from the NEXUS program, sampling rest-frame timescales of $\sim 1-3$ months. Overall, the LRD population shows significantly enhanced Balmer decrement compared with both blue JWST AGNs at similar redshifts and 56 low-redshift broad-line AGNs matched in H$\rmα$ luminosity. The rest-optical continua of LRDs show l…

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astro-ph.HEastro-ph.COastro-ph.IM2026年8月3日

Parameter Estimation Horizon of Core-Collapse Supernovae with a Network of Gravitational-Wave Detectors

Almat Akhmetali, Y. Sultan Abylkairov, Solange Nunes, José Antonio Font, Michele Zanolin, Ernazar Abdikamalov

Core-collapse supernovae are among the most promising yet still undetected sources of gravitational waves. A future detection would provide a direct view of the physical processes occurring deep inside a collapsing star. In this work, we investigate how networks of current and future gravitational-wave detectors can constrain the properties of rapidly rotating core-collapse supernovae using their characteristic core-bounce and early post-bounce signals. Using deep-learning techniques, we estimat…

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astro-ph.GA2026年8月3日

Evolution of superthin galaxies under Milgromian dynamics

Zhe-Qi Huang, Hao Chen, Xin-Lei Ge, Cheng-Qun Pang

This work investigates the long-term evolution of the vertical structure of superthin galaxies within the framework of Milgromian dynamics (MOND). By constructing an observationally constrained model of UGC 7321, we test whether its disc can maintain an extremely flattened structure in a MOND gravitational field. We also construct models with different values of the MOND depth index $D_{\rm M}$ to study how the global MOND depth affects disc evolution. We perform three-dimensional hydrodynamical…

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astro-ph.SR2026年8月3日

Deformation of the CME and CME-driven shock due to interaction with the ambient solar wind: I. Modelling with Cone Model

A. Niemela, A. Valentino, J. Magdalenic

Context. The near-Earth environment is continuously impacted by the solar wind and the transients embedded in it. The largest eruptions of plasma and magnetic field at the Sun are Coronal Mass Ejections (CMEs), which, upon reaching Earth, can induce geomagnetic storms and disrupt our technologically advanced societies. Aims. We aim to improve our understanding of how CMEs and CME-driven shock waves interact with the ambient solar wind, and how the resulting deformations in time and space affect…

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astro-ph.GA2026年8月3日

Spatially resolved thermal dust emission in the L1157 outflow reveals grain-driven molecular enrichment

Siyi Feng, Hauyu Baobab Liu, Yang Lu, Qiancheng Yang, Sheng-Yuan Liu, Paola Caselli, Zhi-Yu Zhang, Shuting Lin et al.

Protostellar outflow shocks reshape local dust properties and molecular chemistry. The L1157 outflow is an archetypal chemically rich shocked region, but the thermal dust associated with its successive shocks has remained unresolved because molecular-line contamination obscures the broadband continuum. We obtained new James Clerk Maxwell Telescope (825--906 $μ$m) spectral-line observations and Submillimeter Array (1.1--1.4 mm) continuum observations toward L1157 B0-B1-B2, probing spatial scales…

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astro-ph.IM2026年8月3日

Hard X-Ray Focal-Plane Compton Spectro-Polarimeter: Detector Development and Sensitivity Evaluation

Abhay Kumar, Tanmoy Chattopadhyay, Santosh V. Vadawale, N. P. S. Mithun

The scientific potential of X-ray polarimetry has long been recognized, yet the challenges of measuring polarization have left it largely unexplored, mainly in the hard X-ray regime. With the advent of hard X-ray focusing optics, sensitive focal-plane Compton polarimeters are now feasible. An early example is CXPOL (Compton X-ray Polarimeter), developed at Physical Research Laboratory (PRL), India, which demonstrated 20 - 80 keV polarimetric capabilities using a plastic scatterer and a CsI(Tl) a…

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astro-ph.IMastro-ph.SR2026年8月3日

In orbit background for hard X-ray CubeSat polarimeters: case study of the CUSP mission in low-earth orbit

Abhay Kumar, Giovanni Lombardi, Riccardo Campana, Giovanni De Cesare, Sergio Fabiani, Ettore Del Monte, Andrea Alimenti, Enrico Costa et al.

The CUbesat Solar Polarimeter (CUSP) project aims to measure the linear polarization of solar flares in the 25 - 100 keV hard X-ray band using a Compton scattering polarimeter. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop innovative CubeSat technologies and missions. As part of CUSPs Phase B study, initiated in December 2024 and closed on July 2nd, 2026, estimating the in orbit background to optimize the signal-to-background ratio was one o…

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astro-ph.GAastro-ph.SR2026年8月3日

Dust Seeding Molecules in a Massive Protostar -- Detection of TiO in Orion Source I

Ziwei E. Zhang, Nami Sakai, Marcelino Agundez, Linda Podio, Claudio Codella, Tomoya Hirota, Adam Ginsburg, Brett McGuire et al.

We report the first detection of TiO in star-forming regions based on Atacama Large Millimeter/submillimeter Array observations of Orion Source I, a well-characterized massive protostar. Multiple rotational transitions are identified, with emission spatially resolved within $\sim 50$ au, showing a compact distribution with a velocity structure consistent with the base of a rotating outflow. The spatial and velocity distributions of TiO are consistent with those of AlO, with both species being ke…

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hep-phastro-ph.HEhep-ex2026年8月3日

Search for active-sterile neutrino transitions using Pierre Auger Observatory data

The Pierre Auger Collaboration, A. Abdul Halim, P. Abreu, M. Aglietta, M. Ahmed, I. Allekotte, K. Almeida Cheminant, R. Aloisio et al.

We investigate the sensitivity of the Pierre Auger Observatory to physics beyond the Standard Model arising from magnetic-moment-induced transitions between active and heavy sterile neutrinos. Such dipole portal interactions can enhance neutrino-nucleon cross sections above a kinematic threshold set by the sterile neutrino mass, leading to observable modifications of neutrino detection rates at ultrahigh energies (UHE). We estimate the impact of these interactions on both down-going and Earth-sk…

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astro-ph.IMastro-ph.EPastro-ph.SR2026年8月3日

MiraSOL: a DMD-based spectrograph for resolved solar spectroscopy

Christian Robles, Suvrath Mahadevan, Lawrence Ramsey

We present the science motivation, preliminary design requirements, device laboratory testing and a prototype for an new experimental platform for solar observations, MiraSOL. MiraSOL will use digital micromirror technology to actively select regions on the solar disk for spectroscopic observation to determine the spatially dependent radial velocity signatures of stellar variability, and can create transits on the solar disk to probe the effects of stellar contamination on exoplanet transmission…

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astro-ph.HE2026年8月3日

Spectral decoherence without depolarization in curvature radiation

A. G. Tevzadze, N. L. Shatashvili

Context: Fast radio bursts often exhibit strong linear polarization together with pronounced spectral structure. Yet in coherent curvature radiation, spectral decoherence and depolarization are not necessarily simultaneous. Aims: We investigate spectral and polarization coherence in curvature radiation from extended ultrarelativistic sources. Methods: Using the coherency matrix formalism together with an asymptotic phase expansion for a uniformly emitting extended source, we derive the spectral…

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astro-ph.HEgr-qc2026年8月3日

Signatures of Lorentz violation in bright ring for Sgr A* images by radiation ineffective accretion flows

Cuiyu Zhao, Songbai Chen, Jiliang Jing

We have investigated effects of Lorentz violation (LV) on bright ring in Sgr A* images illuminated by the 230 GHz thermal synchrotron emission from radiation ineffective accretion flows around a rotating LV black hole within the low-energy Hořava gravity framework. Our results reveal that the LV parameter reduces the bright ring diameter yet increases its width, luminosity, azimuthal asymmetry and orientation angle. Higher spin parameter strengthens the LV-induced effects on bright ring properti…

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astro-ph.SRastro-ph.IM2026年8月3日

Cross-Calibration of Chandrayaan-2 XSM with INSPIRESat-1 DAXSS and GOES-16 XRS

N. P. S. Mithun, Santosh V. Vadawale, Asif M. Mandayapuram, M. Shanmugam, Soumya Kohli, Mehul R. Pandya, Anil Bhardwaj, Robert Sewell et al.

X-ray spectroscopic observations of the solar corona and flares provide crucial diagnostics of plasma properties and are essential for understanding the physical processes responsible for coronal heating and solar eruptive activity. The Chandrayaan-2 Solar X-ray Monitor (XSM) provides disk-integrated spectra of the Sun in the 1--15~keV soft X-ray band, enabling modeling of the thermal X-ray emission from the corona across quiet phases to intense solar flares. XSM has been operational for about s…

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astro-ph.HEastro-ph.EPastro-ph.SR2026年8月3日

Probing strange quark matter objects with future space-based gravitational wave detectors DECIGO and BBO

Abdusattar Kurban, Xia Zhou, Na Wang, Yong-Feng Huang, Wenming Yan, Jianping Yuan, Ali Esamdin, Rai Yuen et al.

The Strange Quark Matter (SQM) hypothesis posits that objects composed of SQM could exist across a wide mass range, from strange planets (SPs) to strange stars (SSs). It has been proposed that gravitational waves (GWs) emitted by inspiraling SS-SP systems may be detectable by ground-based GW observatories such as advanced LIGO and the Einstein Telescope. Nevertheless, such a system may undergo an extended period of orbital evolution in a close configuration before entering the inspiraling phase.…

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astro-ph.IM2026年8月3日

Design and modeling of an oblique incidence dichroic mirror for a high contrast imaging system

Joanna Rosenbluth, Ramya Anche, Kyle Van Gorkom, Nikoli Cooper, William Melby, Daewook Kim, Ewan Douglas

The proposed Habitable Worlds Observatory (HWO) aims to detect and characterize Earth-like planets around Sun-like stars from the ultraviolet to the infrared using high-contrast imaging. A dichroic mirror is a natural choice for splitting light between multiple wavelength channels in such a system, but the coating must introduce minimal polarization aberrations and chromatic wavefront errors (WFE) to avoid limiting contrast. We present the design of a long-pass dichroic mirror operated at a $7^\…

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astro-ph.IM2026年8月3日

Towards optimal photometric calibration of digital astronomical plates with deep learning

Mingyang Ma, Haibo Yuan, Lin Yang, Kai Xiao, Bowen Huang, Shiyin Shen, Zhengjun Shang, Yong Yu et al.

Photometric calibration of digitized photographic plates is commonly modeled with separable magnitude-, color-, and position-dependent terms, but this separability can break down when image quality varies across the field in a magnitude-dependent way, leaving coupled spatial systematics in the residuals. We introduce a deep-learning calibration framework, the Multi-Feature Fused Network (MFF-Net), which takes instrumental magnitude, color, and pixel coordinates as input and learns a single nonli…

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physics.plasm-phastro-ph.GAastro-ph.HE2026年8月3日

Sub-sonic compressible magnetohydrodynamic turbulence I. Alfvénic and fast-magnetosonic injection, amplitude dependence, and compressibility effects

Eleonora Puzzoni, Silvio Sergio Cerri, Dimitri Laveder, Thierry Passot, Pierre-Louis Sulem

We investigate how sub-sonic compressible magnetohydrodynamic (MHD) turbulence properties that are relevant for cosmic-ray (CR) transport in the Galaxy are affected by the nature and amplitude of initial fluctuations, and by the plasma compressibility $β$. We perform 3D simulations of decaying compressible ideal-MHD turbulence at $1024^3$ resolution with the PLUTO code. The level of density fluctuations in fully developed turbulence is insensitive to whether this state is reached starting from A…

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astro-ph.HE2026年8月3日

Propagation Diagnostics of Supernova Remnant Environments around Young Repeating FRBs. I. Hydrodynamic Evolution of the Source-Local Dispersion Measure

Xiang-Er Fang, Zhen-Yin Zhao, Yi-Qing Lin, Hao-Tian Lan, Fa-Yin Wang

Repeating fast radio bursts may reside in young supernova remnant (SNR) environments whose evolving plasma contributes to the observed dispersion measure (DM). We use two-dimensional axisymmetric hydrodynamic simulations to study the interaction between a continuous anisotropic wind from a young neutron star and homologously expanding supernova ejecta. We follow the evolution to approximately 160 yr and calculate the source-local DM along different viewing directions, using a passive tracer to s…

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astro-ph.GA2026年8月2日

The physical mechanism for two rapid changing-look AGNs: SDSS J0225+0030 and SDSS J1723+5504

Shuang-Liang Li, Xinwu Cao, Wei-Min Gu

SDSS J0225+0030 and SDSS J1723+5504 are two turn-on changing-look active galactic nuclei (CL AGNs) with transition timescales shorter than one year. Such short timescales pose a challenge for the current physical models of CL AGNs. We investigate this issue by exploring two possible mechanisms in this work. First, we consider the effect of a large-scale magnetic field on the viscous timescale, which can increase the radial velocity of the accretion disk. However, it is found that the timescale g…

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astro-ph.HE2026年8月2日

Deciphering the "Green Monster" in Cassiopeia A: Puncturing and sculpting a heterogeneous circumstellar shell

S. Orlando, H. -T. Janka, D. Milisavljevic, I. De Looze, T. Temim, R. Fesen, B. -C. Koo, M. Miceli et al.

JWST observations of Cassiopeia A have revealed the "Green Monster" (GM), a pockmarked region of shocked circumstellar medium (CSM) characterized by circular holes surrounded by bright rings. The origin of these structures remains debated, with proposed mechanisms including post-shock sculpting by ejecta fingers and pre-shock puncturing by fast-moving knots (FMKs). We investigate the physical viability of the FMK-driven scenario using three-dimensional hydrodynamic simulations of FMKs interactin…

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astro-ph.HE2026年8月2日

The PSR J0435+3233 Triple System

Z. L. Yang, J. L. Han, Y. Yan, Bin Liu, Y. L. Guo, M. K. Yang, Bo Wang, W. M. Gu et al.

The detailed evolution of triple star systems is complicated and poorly known. Based on the optical/infrared and gamma-ray archived data, we identified that the pulsar, PSR~J0435+3233, is a gamma-ray pulsar in a hierarchical triple system, with a helium white dwarf (WD) as a close inner binary companion and a Sun-like star as the distant tertiary. PSR~J0435+3233 and the WD companion are in a circular orbit with a period of $P_{\rm orb1} = 8$~days and an eccentricity of $e=0.00016$.The tertiary i…

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astro-ph.HE2026年8月2日

Simulations of Electromagnetic Cascades in the Intergalactic Medium with Plasma Instabilities: the grplinst Code

Rafael Alves Batista, Andrey Saveliev

Electromagnetic cascades initiated by TeV gamma rays from distant blazars provide one of the cleanest indirect probes of the intergalactic medium and, in particular, of intergalactic magnetic fields. However, their interpretation is not completely clear because of an open theoretical question: the extent to which the electron-positron beams generated in the cascade can lose energy through collective plasma processes. If this occurs before inverse Compton scattering produces secondary gamma rays,…

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astro-ph.COastro-ph.GAastro-ph.IM2026年8月2日

AGN Reverberation Mapping with LITMUS: Fundamental Limits on lag Recovery Rates

Hugh McDougall, Tamara M. Davis, Benjamin J. S. Pope, Paul Martini, Zhefu Yu, Chris Lidman, Geraint F. Lewis

Reverberation mapping of active galactic nuclei provides one of the most direct probes of the geometry and kinematics of the broad-line region by measuring time delays between continuum and line variability. Modern RM surveys frequently suffer difficulties with lag measurements due to poor signal to noise and aliasing, whereby multimodal lag posterior distributions arise due to seasonal gaps in our data. These challenge the reliability of commonly used fitting tools such as JAVELIN, which can re…

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astro-ph.EP2026年8月2日

CHEOPS photometry from 2024 reveals a reversal in the transit-timing variations of AU Mic c

Z. Garai, Gy. M. Szabó, D. Gandolfi, A. Brandeker, A. Bonfanti, N. Billot, W. Benz, A. Heitzmann et al.

We present new CHEOPS transit observations of AU Mic b and AU Mic c obtained between June and September 2024, extending the baseline of transit-timing measurements of this young planetary system. For AU Mic b, the timing signal is well established, with a semi-amplitude (10 $\pm$ 3 min) and a characteristic modulation timescale (1168 $\pm$ 20 d) consistent with previous determinations. By contrast, the new CHEOPS data show that the large transit-timing deviation of AU Mic c reported previously w…

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astro-ph.EPastro-ph.IM2026年8月2日

Orbital Periods and Equilibrium Temperatures from Single TESS Transits with a Physics-Informed Neural Network

Muhammad Hassan Javed

Planets with orbital periods longer than a TESS sector produce a single transit, and no periodogram method can measure their period: with one transit, every trial period longer than the observing baseline fits the data identically. We show this is not a sensitivity limit but a structural one -- across 16 confirmed single-transit planets, Box Least Squares returns a power spectrum that is numerically constant over 95% of its search grid, and widening that grid from 27 to 200 days changes the medi…

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astro-ph.GA2026年8月2日

Identification and Study of Irregular Radio Sources with SKA Continuum Surveys

Tapan K. Sasmal, Xuelei Chen, Baoqiang Lao, Soumen Kumar Bera, Yougang Wang, Soumen Mondal, Taotao Fang, Renyue Cen et al.

Radio galaxies show a wide range of morphologies, from regular double-lobed systems to more complex and distorted radio structures. In this chapter, we focus on irregular radio morphologies, defined as sources in which the radio jets and lobes deviate from a straight and symmetric structure. Bent-tail radio galaxies and winged radio galaxies are two important examples of such sources. Bent-tail radio galaxies show curved jets or lobes, mainly shaped by the interaction between radio plasma and th…

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