研究動向

astro-ph.HE2026年9月18日

Little Red Dots As Super-Eddington Fountain Flows

Nicholas Kaaz, Eliot Quataert, Taya Govreen-Segal, Hanpu Liu

Little red dots (LRDs) may be powered by supermassive black holes (SMBHs) accreting above the Eddington limit. Spectroscopy of LRDs often shows absorption troughs blueshifted by $\sim100-300\,{\rm km\,s^{-1}}$, implying a slow wind. This is puzzling: super-Eddington disks drive much faster winds, $\gtrsim10^3-10^4\,{\rm km\,s^{-1}}$. We argue that LRDs are super-Eddington SMBHs viewed off-axis and engulfed in a slow wind that covers most sight-lines; the fast wind escapes near the poles. Trapped…

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astro-ph.GA2026年9月18日

Free-Free Radio Emission from Little Red Dots as a Probe of Ionized Gas

Takumi S. Tanaka, Kohei Inayoshi, Zu Yan, Tomokazu Kiyota, Yuichi Harikane, John D. Silverman

Recent studies have hypothesized that little red dots (LRDs) are rapidly accreting black holes surrounded by dense gaseous environments. Both neutral and ionized gas play a key role in explaining many of the puzzling spectral features of LRDs, including the emission line profiles in the optical-infrared bands, although the physical conditions required for these gas components remain poorly constrained. We propose that free-free emission provides a robust, independent probe of ionized gas in LRDs…

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astro-ph.GA2026年9月18日

A near-IR survey of luminous asymptotic giant branch stars in the satellites and stellar halo of M31

Jess M. Howell, Annette M. N. Ferguson, Olivia C. Jones, Mike. J. Irwin, Maria-Rosa L. Cioni, Geraint F. Lewis, Nicolas. F. Martin, Alan. W. McConnachie et al.

We investigate the dwarf spheroidal (dSph) satellites and stellar halo of M31 using near-infrared imaging from the Wide-Field Camera on the UKIRT 3.8 m telescope. Our homogeneous analysis covers the stellar extents of 12 dSphs, as well as their surrounding halo field populations. We identify carbon-rich (C) and oxygen-rich (M) thermally-pulsing AGB stars (TP-AGBs) using colour-magnitude and colour-colour diagrams, which also allows for effective contaminant rejection. TP-AGB stars are detected i…

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astro-ph.HEastro-ph.IM2026年9月18日

Systematic Effects of Hydrogen and Helium Atmosphere Mismatch on Radius Inference in PSR~J0740+6620-like Synthetic NICER Data

Isiah M. Holt, M. Coleman Miller, Alexander J. Dittmann, Frederick K. Lamb

Constraints on neutron star radii provide insight into the properties of the cold, dense matter in their interiors. Previous studies using synthetic Neutron star Interior Composition Explorer (NICER) pulse waveform data have demonstrated that radius inferences derived therefrom are robust against several classes of modeling systematics. Here we explore the consequences of assuming the wrong atmospheric composition, using synthetic data based on the $\sim 2.1~M_\odot$ pulsar PSR~J0740$+$6620. We…

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astro-ph.HE2026年9月18日

A systematic search for long GRBs without supernovae: global properties and rate of events

Yu-Han Yang, Eleonora Troja, Nicolas Monsalves, Massine El Kabir, Narjes Shahamat Dehsorkh, Hira Waseem

Some long duration gamma-ray bursts (LGRBs) are not associated with bright supernovae (SNe), indicating that their explosion mechanism differs from the traditional collapsar channel. SN-less LGRBs are rare, thus it remains unclear whether they are sporadic outliers or a substantial component of the GRB population. In this work, we use two decades of Swift observations to conduct a systematic search for nearby ($z\lesssim$0.35) LGRBs without a confirmed SN association. Our analysis reveals a hete…

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astro-ph.EP2026年9月18日

Fragmentation Dynamics of Pristine Interstellar Comets: An Exploratory Multi-Physics Simulation Study

Behrooz Karamiqucham

We present an exploratory numerical model for the thermal evolution and fragmentation of pristine interstellar comets during a first passage through the inner Solar System, and we apply it across a grid of perihelion distances (q=0.25--1.5~AU) and tensile strengths (σ_t=50--500~Pa). The model follows a single nucleus (M_0=2\times10^{12}~kg, R_0\approx1060~m, dust/ice =1, ice composition 35\% CO, 30\% CO_2, 15\% CH_4, 20\% H_2O) along a continuous hyperbolic trajectory, solving heat conduction in…

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astro-ph.EP2026年9月18日

Fragmentation Dynamics of Pristine Interstellar Comets: An Exploratory Multi-Physics Simulation Study

Behrooz Karamiqucham

We present an exploratory numerical model for the thermal evolution and fragmentation of pristine interstellar comets on a first passage through the inner Solar System, applied over a grid of perihelion distances ($q=0.25$--$1.5$~AU) and tensile strengths ($σ_t=50$--$500$~Pa). A single nucleus ($M_0=2\times10^{12}$~kg, $R_0\approx1.06$~km, dust/ice $=1$, ices 35\% CO, 30\% CO$_2$, 15\% CH$_4$, 20\% H$_2$O) follows a hyperbolic trajectory from an initially 30~K state, with heat conduction, energy…

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physics.space-phastro-ph.SR2026年9月18日

Microphysical Diversity in Two Very Closely Spaced Magnetic Switchbacks Observed by Parker Solar Probe

Dipali Vadher, Ankush Bhaskar, Smitha Thampi, Kamlesh Pathak

Parker Solar Probe observations near the Sun reveal frequent, sudden reversals of the magnetic field known as switchbacks (SBs). Despite their ubiquity, the internal plasma structure and associated heating within SBs remain poorly understood. We present a case study of two closely spaced SBs (referred in text as SB_1 and SB_2) observed on 24 January 2020 using high-cadence magnetic and plasma measurements. Magnetic fluctuations are decomposed into components parallel and perpendicular to the mea…

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astro-ph.EP2026年9月18日

The JWST Sub-Jupiters Survey: Direct Imaging Discovery of a Giant Planet and a Debris Disk Around the Young M-dwarf RX J0534.0-0221

Rodrigo Ferrer-Chavez, Jason J. Wang, Kevin Wagner, Kellen Lawson, Aarynn L. Carter, Beth Biller, Raphael Bendahan-West, Patrick McCreery et al.

We present the discovery of RX J0534.0-0221 b, a giant planet orbiting an M-dwarf star in the $β$ Pictoris moving group. RX J0534 was originally observed with JWST/NIRCam in the F444W and F200W filters. Observations in F444W reveal a point source at signal-to-noise ratio $\sim17.5$ at $\sim0.41$ arcsec ($\sim14$ au) from the host star, with no detection of the source in F200W. A follow-up observation with LBTI/LMIRCam in $L'$ band re-detects the source 16 months after the JWST epoch, providing e…

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astro-ph.HE2026年9月18日

Low Frequency Radio Imaging Study of PSR J1818-1607

A. Yadav, M. P. Surnis, B. C. Joshi, M. Bagchi

We report on the low-frequency radio observations of magnetar PSR J1818$-$1607 carried out with the upgraded Giant Metrewave Radio Telescope at band 3 (300$-$500 MHz) and band 4 (550-750 MHz). We have identified the continuum source associated with the magnetar and report variations in flux density and its spectral index. The flux density timeseries for the magnetar reveals the presence of two potential radio flaring episodes with varying spectral properties. We discuss the implications of the s…

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astro-ph.GA2026年9月18日

Local constraints on alcohol--thioalcohol analogs in G35.2N

Xuefang Xu, Shanghuo Li, Qian Gou, Chunguo Duan, Laurent Pagani, Di Li, Jun Kang, Jiaxin Du et al.

The chemistry of sulfur-bearing complex organic molecules in dense star-forming environments remains uncertain, partly because the dominant sulfur reservoirs in dense gas and ices are poorly identified. Alcohol--thioalcohol pairs allow direct comparisons of structurally related O- and S-bearing molecules. We present ALMA Band 6 observations of CH$_3$OH/CH$_3$SH and C$_2$H$_5$OH/C$_2$H$_5$SH toward three spectral-extraction positions (MM3-pos, MM4-pos, and MM5-pos) in the MM3--MM5 region of G35.2…

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astro-ph.EPastro-ph.SR2026年9月18日

Water Cloud and Chemical Modulations in the Coldest Brown Dwarf

Brittany E. Miles, James Mang, Caroline V. Morley, Andrew J. I. Skemer, Melanie Rowland, Brianna Lacy, Genaro Suarez, Channon Visscher et al.

We present high signal-to-noise, medium resolution (R ~ 1000), time-series JWST/NIRSpec spectra of WISE 0855 (265K), the coldest known brown dwarf. Medium resolution, time-series spectroscopy gives us the power to disentangle the effects of chemistry, temperature, and condensates on this cool world. Our observations span 11 hours with a 15 minute cadence covering 2.87 - 5.27 $μ$m. The strongest time variable spectroscopic feature is carbon monoxide gas absorption producing modulations with a pea…

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astro-ph.IM2026年9月18日

All-Fiber Broadband Wavelength-Division Multiplexing using Heterogeneous Photonic Lanterns

Abani Shankar Nayak, Julius Goehring, Martin M. Roth, Kalaga Madhav

This work presents an all-fiber broadband wavelength-division multiplexing architecture using 1x7 heterogeneous photonic lanterns (PLs), specifically PL-(6+1) and PL-(4+3). By combining mismatched single-mode cores, namely SM450 and SMF28, without rigid geometric constraints, these devices break system degeneracy and enable passive, wavelength-selective spatial routing. Experimental characterization reveals distinct dual-regime performance across a wide spectral range. In the visible band (350-7…

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astro-ph.IM2026年9月18日

Offline vs Real-Time Validation and Performance Assessment of Heimdall Detection Pipeline for Fast Radio Bursts

Valentina Cesare, Giovanni Naldi, Francesco Fiori, Andrea Geminardi, Adrian De Barro, Alessio Magro, Hayley Camilleri

Data rates from current radio telescopes are of $\sim$O(10)PB/y and we expect a growth of an order of magnitude for future radio telescopes, e.g. SKA. Coping with these data flows requires a paradigm change in data management: building pipelines with intense I/O between their modules (offline mode) is becoming unsustainable, leading to a transition to a real-time paradigm, where data are moved to RAM, e.g.,through PSRDADA ring buffers. Our objective is to obtain a compact pipeline to efficiently…

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gr-qchep-thmath-phphysics.space-ph2026年9月18日

Gravity from Invariant Weyl-Integrable space-time (IWIST)

José Edgar Madriz Aguilar, A. Bernal, M. Montes, J. Zamarripa

In this paper we propose a geometrically motivated formulation of gravity in an invariant Weyl--Integrable space-time (IWIST), in which the background geometry is not imposed a priori but is dynamically determined through the Palatini variational principle. For a scalar field non-minimally coupled to gravity action, the resulting compatibility condition defines a Weyl--Integrable geometry which is preserved by a local Weyl transformation of the metric and the geo\-me\-tri\-cal scalar field. We c…

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astro-ph.EP2026年9月18日

Coupled Orbital and Interior Evolution of Sub-Neptunes

Ritika Sethi, Sarah Millholland, Tim Hallatt

Recent observations have yielded the first measurements of young exoplanet demographics. Close-in sub-Neptune occurrence rates appear to rise from young ($10-100$ Myr) to intermediate (100 Myr $-$ 1 Gyr) ages and then decline sharply in the old ($\gtrsim 1$ Gyr) Kepler field population. In this paper, we test whether these observations can be explained by the effects of planetary cooling, atmospheric mass loss, and tidal orbital migration, which we model through a fully coupled evolution framewo…

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physics.atom-phastro-ph.IM2026年9月18日

Integration of the NIST Spectroscopic Plate Archive into the Harvard Plate Stacks

Jacob Ward, Thom Burns, Lisa Bravata, Gillian Nave, Adam Foster

For many decades, the National Institute of Standards and Technology (NIST) Atomic Spectroscopy Group housed a growing collection of thousands of photographic glass plate negatives. With the closure of the NIST Atomic Spectroscopy Group in March 2025, the irreplaceable collection needed a new home. Staff from NIST were contacted by staff from the Harvard Plate Stacks at the Center for Astrophysics | Harvard & Smithsonian (CfA). The Harvard Plate Stacks is the largest collection of astronomical g…

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astro-ph.EP2026年9月18日

Formation of Ryugu's parent planetesimal beyond the CO$_{2}$ snow line from small pebbles: insights from thermal evolution modeling

Sota Arakawa, Hidenori Genda, Noriyuki Kawasaki, Wataru Fujiya, Yosei Iwasaki, Shigeru Wakita

Astronomical observations of planet-forming circumstellar disks indicate that planetesimals form from 0.1-mm- to 1-cm-sized dust aggregates, commonly called ``pebbles.'' When such pebbles accrete beyond the water snow line, the resulting icy planetesimals undergo water--rock differentiation and develop porous pebble-pile cores whose voids are saturated with liquid water. Circulation of this water enhances heat transport in the core, suppressing the temperature rise caused by the decay of radionu…

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astro-ph.GA2026年9月18日

Intracluster light in the infall region of simulated protoclusters of galaxies

S. V. Werner, M. Jauzac, M. Montes, D. Rennehan, G. Mahler, A. Niemiec, Y. Jiménez-Teja

Intracluster light (ICL) is a diffuse stellar component in galaxy clusters, made of stars following the potential of the cluster. Despite its potential to unveil the accretion history of clusters, the ICL in protoclusters remains poorly understood in simulations and observations. We analyse protoclusters in TNG-Cluster and Manhattan Suite simulations to investigate when ICL forms, its host progenitors, and environments where it forms. We find a considerable amount of ICL in the infall region of…

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physics.ins-detastro-ph.COastro-ph.IMhep-exhep-ph2026年9月18日

Mineral Detection of Neutrinos and Dark Matter 2026 Proceedings

Alexey Elykov, Patrick Stengel, Natsue Abe, Daniel Ang, Lorenzo Apollonio, Levente Balogh, Laura Baudis, Chinmay Bharathulwar et al.

The fourth "Mineral Detection of Neutrinos and Dark Matter" (MDvDM'26) meeting was held April 14-17, 2026 in Karlsruhe, Germany, hosted by the Institute for Astroparticle Physics (IAP) at Karlsruhe Institute of Technology (KIT). These proceedings detail the contributions that were presented during MDvDM'26, illustrating the unprecedented progress in theoretical, computational and experimental studies towards the realization of the concept of mineral detectors. Mineral detectors represent an emer…

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astro-ph.GA2026年9月18日

Interstellar disparity: N- vs O-bearing molecules: A multidisciplinary perspective across interstellar environments

Mathilde Bouvier, Joan Enrique-Romero, Marta De Simone

Observations of O- and N-bearing molecules reveal systematic chemical differentiation across a wide range of interstellar environments. This pattern is peculiar and its origin likely reflects a combination of physical conditions, chemical pathways, and observational effects rather than a single mechanism. In this paper, we provide a comprehensive overview of the current understanding of the N-bearing and O-bearing species and their relative behaviour in the interstellar medium, integrating resul…

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astro-ph.GA2026年9月17日

Thioacetaldehyde (CH3CHS) on interstellar ices: a key molecule to unravel two chemical dichotomies in the ISM

María Mallo, Miguel Sanz-Novo, Marcelino Agúndez, José Cernicharo, Gisela Esplugues, Víctor M. Rivilla, Izaskun Jiménez-Serra, Carlos Cabezas et al.

Thioacetaldehyde (CH3CHS), recently detected in TMC-1, has an abundance approximately 36 times lower than its oxygen analog, acetaldehyde (CH3CHO). This makes the CH3CHS/CH3CHO pair the one with the largest column density difference among the detected oxygen/sulfur analogue pairs in this cloud. We investigate the hydrogenation pathways of CH3CHS to address two chemical dichotomies in the ISM: (i) the differenciation between CH3CHS and CH3CHO, and (ii) the apparent absence of both CH3CHS in the G…

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hep-phastro-ph.IMhep-exhep-latquant-ph2026年9月17日

Particle Physics Driven by Quantum Technology - Quantum Simulations and Quantum Sensing

Itay M. Bloch, Marcela Carena, Yifan Chen, Xinran Li, Ying-Ying Li, Jing Shu

We review recent advances in particle physics enabled and motivated by the rapid progress of quantum technologies. The continued development of quantum computing toward large-scale, fault-tolerant systems has the potential to address dynamical problems that remain extremely challenging for classical computational approaches, opening new avenues for studying nonperturbative dynamical processes. Tabletop detectors and quantum-enhanced technologies have reached unprecedented sensitivities, enabling…

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astro-ph.EPastro-ph.IMastro-ph.SR2026年9月17日

Daytime seeing variations in Paranal through a SHABAR system. Description of the method and first measurements from the PoET solar telescope

A. M. Silva, B. Wehbe, A. Oliveira, M. Abreu, C. Cardenas-Conde, A. Cabral, P. Moreno, J. H. C. Martins et al.

Aims. In this paper we present the software and first seeing measurements from a SHAdow Band Ranger (SHABAR) system that is coupled with the recently comissioned PoET solar telescope, installed at ESO's VLT platform in the Paranal Observatory. The seeing measurements that are collected by this system play a pivotal role in the observational strategy of PoET, as it employs apertures ranging between 1 and 55 arcseconds to observe resolved solar regions. As such, the usage of the smaller apertures…

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astro-ph.GA2026年9月17日

ELUCID. IX. Recovering the Substructures and History of the Coma Cluster

Xiong Luo, Huiyuan Wang, Weiguang Cui, Yipeng Jing, Neal Katz, Romeel Davé, Houjun Mo, Xiaohu Yang et al.

We employ constrained hydrodynamic simulations of the Coma galaxy cluster from the ELUCID project to study its substructures and assembly history. Our simulations accurately reproduce the global properties of Coma, including its position, virial mass, radius, and surrounding large-scale filaments. Using a combined HBT+SKID method, we obtain a total intracluster light (ICL) fraction of $12.2\%-23.5\%$, consistent with recent observations. The mass-weighted ICL profiles of velocity dispersion, ste…

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astro-ph.GA2026年9月17日

ELUCID. IX. Recovering the Substructures and History of the Coma Cluster

Xiong Luo, Huiyuan Wang, Weiguang Cui, Yipeng Jing, Weipeng Lin, Neal Katz, Romeel Davé, Houjun Mo et al.

We employ constrained hydrodynamic simulations of the Coma galaxy cluster from the ELUCID project to study its substructures and assembly history. Our simulations accurately reproduce the global properties of Coma, including its position, virial mass, radius, and surrounding large-scale filaments. Using a combined HBT+SKID method, we obtain a total intracluster light (ICL) fraction of $12.2\%-23.5\%$, consistent with recent observations. The mass-weighted ICL profiles of velocity dispersion, ste…

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astro-ph.GAastro-ph.SR2026年9月17日

The Galactic centre G+0.633-0.0604 molecular cloud: A new astrochemical gold mine: II. Chemical richness

D. San Andrés, V. M. Rivilla, L. Colzi, M. Sanz-Novo, S. Martín, I. Jiménez-Serra, S. Zeng

In recent years, the inventory of interstellar molecules has rapidly grown, yet detections of complex species are confined to a few chemically rich sources, raising the question of whether such complexity is genuinely rare or shaped by observational biases. We present the Galactic Centre G+0.633-0.0604 molecular cloud, located in the southern part of the Sgr B2 complex, as a new and very promising laboratory for the discovery of new interstellar molecules. We analysed data from a high-sensitivit…

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astro-ph.GA2026年9月17日

Water maser detections toward 70 $μ$m infrared dark clumps at early star formation stage

Chao Ou, Shanghuo Li, Junzhi Wang, Ian W. Stephens, Yuqiang Li

Water masers provided powerful probes of shocked gas and protostellar activity during the early stages of star formation. Using VLA K-band observations of the 22 GHz water line, we report the first detections of water masers toward dense cores in five 70 $μ$m infrared dark clumps, providing evidence for active star formation at an early evolutionary stage. We detected ten unresolved maser spots comprising thirteen velocity components, with peak flux densities of 13--499 mJy and deconvolved full…

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astro-ph.SR2026年9月17日

Gaia method paper: an algorithm to detect flare events in Gaia time-series

E. Distefano, A. C. Lanzafame, A. F. Lanza, S. Messina, I. Pagano, M. Audard, G. Jevardat de Fombelle, B. Holl et al.

The third Gaia data release (GDR3) includes the gdr3_rotmod catalogue of 474026 stars with variability that is attributed to magnetic activity analogous to that observed in the Sun, arising from rotational modulation induced by spots and faculae. These stars are therefore expected to exhibit flaring activity driven by magnetic reconnection processes. We aim to demonstrate that stellar flares can be reliably identified and characterised in the sparsely sampled \gaia\ photometric time series. We d…

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astro-ph.GA2026年9月17日

Revisiting the interpretation of HI Zeeman measurements in the diffuse interstellar medium

Adrien Barthas, Andrea Bracco

The HI Zeeman effect provides one of the few direct probes of magnetic field strengths in the diffuse atomic interstellar medium (ISM), yet the physical quantity recovered by the standard weak-field estimator remains uncertain in multiphase gas. This is especially relevant to the low-column-density branch of the observed magnetic field--column density relation, which is nearly flat below NH~1E22 cm-2 and remains difficult to explain theoretically. We investigate this issue using synthetic HI Zee…

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