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Research Trends

Latest preprints in space engineering and astrophysics.

astro-ph.GAastro-ph.COastro-ph.IM

Reading Between the Lines: Forward Modeling Dust, Continuum, and Spectral Cleaning for Multi-Line Intensity Mapping

Anirban Roy, Rachel S. Somerville, Anthony R. Pullen

Line intensity mapping (LIM) offers a tomographic view of galaxy evolution by measuring the aggregate emission from unresolved galaxies. In the optical and near-infrared, the line emission is accompanied by much brighter continuum emission that must be removed to recover line auto- and cross-power spectra. We develop a forward-modeling framework using a $\sim2$deg$^2$ lightcone drawn from a cosmological $N$-body simulation populated with galaxies using a physics-based semi-analytic model (SAM).…

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astro-ph.SRastro-ph.GAastro-ph.IM

A Probabilistic Framework for Population Studies of the Solar Neighborhood: Application to SDSS-V and Gaia

Ilija Medan, Keivan G. Stassun, Zachary Way, Guy S. Stringfellow, Alexandre Roman-Lopes, Jiadong Li, Madeline Lucey, Andrew R. Casey et al.

Studies of the Solar Neighborhood require spectroscopic follow-up of stars identified in astrometric surveys to fully characterize their physical properties. The SDSS-V Solar Neighborhood Census (SNC) is a dedicated program to observe stars within 100~pc. However, due to competing observing programs and fiber assignment constraints, the resulting sample carries severe and complex selection effects. A framework is presented for characterizing the selection function of the SDSS-V SNC relative to t…

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astro-ph.GA

Rapid growth in a dual AGN during a gas-rich merger at z~4.5

Hyewon Suh, Roberto Decarli, Emanuele Paolo Farina, Julia Scharwächter, Mar Mezcua, Giorgio Lanzuisi, Federica Loiacono, Brian C. Lemaux et al.

The late stages of galaxy mergers - when two supermassive black holes (SMBHs) reach kiloparsec-scale separations - represent a critical phase for understanding SMBH growth, galaxy co-evolution, and the progenitors of low-frequency gravitational waves. Yet confirmed close-separation (<3 kpc) dual active galactic nuclei (AGNs) remain confined to the local Universe, despite predictions that such systems should be common in the merger-rich early Universe. Here we report the discovery of LID-1166, a…

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astro-ph.IMastro-ph.GAphysics.comp-ph

A Scalable Fast Multipole Method Poisson Solver for the RAMSES code: II. Adaptive Mesh Refinement and Adaptive Time Stepping

Jun-Young Lee, Romain Teyssier

We present an extended implementation of a scalable, O(N) Poisson solver based on the fast multipole method (FMM), fully compatible with adaptive mesh refinement (AMR) and adaptive time stepping (ATS) within the RAMSES framework. Building on the unigrid algorithm in Lee & Teyssier (2026), we introduce several novel elements, including the use of multiple FMM trees, one for each AMR level, a merged FMM tree for all active levels to optimize neighbor searches, and the introduction of the concept o…

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astro-ph.HEhep-exhep-ph

Four, One, and None: Quantifying the Ultra-High-Energy Neutrino Anomaly Across ANITA-IV, KM3NeT, and IceCube

Dibya S. Chattopadhyay, Carlos A. Argüelles, Vedran Brdar

The four near-horizon neutrino-like events reported by ANITA-IV and the ultra-high-energy track-like event KM3-230213A observed by KM3NeT imply neutrino event rates that are in tension with the absence of corresponding events at IceCube. In this work, we perform a joint analysis of these events, taking into account the absence of any corresponding ones at IceCube. We construct semi-analytic, energy- and direction-dependent effective areas for the three detectors and account for the time-dependen…

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astro-ph.GAastro-ph.HE

Extreme Variability Reveals How the Eddington Ratio Regulates Coronal Power in Active Galactic Nuclei

Arghajit Jana, Claudio Ricci, Franz E. Bauer, Kriti Kamal Gupta, Benny Trakhtenbrot, Alessia Tortosa, Ruancun Li, Luis C. Ho et al.

The bolometric luminosity ($L_{\rm bol}$) of active galactic nuclei (AGNs) is a key tracer of accretion physics, but its direct determination is often hindered by limited spectral coverage and contamination of the host galaxy. Bolometric corrections ($κ_λ = L_{\rm bol}/L_λ$) offer a practical means of estimating $L_{\rm bol}$, with the X-ray bolometric correction ($κ_{\rm 2-10}$) being crucial for exploring the coupling between the accretion disk and the X-ray corona. Here we present multi-epoch…

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astro-ph.GA

A pilot sample of Planck-selected strongly lensed sub-mm galaxies: NOEMA observations and physical characterisation

Leonardo Trobbiani, Matteo Bonato, Ivano Baronchelli, Gianfranco De Zotti, Mattia Negrello, Marika Giulietti, Cristian Vignali, Marcella Massardi et al.

The extreme brightness of high-$z$ strongly lensed galaxies detected by Planck surveys, thanks to their exceptionally large gravitational magnifications, offers a unique opportunity to investigate in extraordinary detail their structure and kinematics during their active star-formation phase. As a step in this direction, we present and analyse NOEMA imaging and spectroscopic data for four lensed high-z galaxy candidates. We performed continuum and line imaging of the sources at 2 and 3 mm bands…

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astro-ph.SRastro-ph.GA

Large Magellanic Cloud Globular Clusters in the Near-infrared. I. RR Lyrae in Reticulum

Anupam Bhardwaj, Susmita Das, Prashant Nishad, Marina Rejkuba, Giulia De Somma, Marcella Marconi, Chow-Choong Ngeow, Vincenzo Ripepi et al.

Reticulum is an old, metal-poor, and sparsely populated globular cluster in the outer regions of the Large Magellanic Cloud (LMC) and hosts a rich population of RR Lyrae stars. Being as close as possible to a single stellar population with negligible metallicity spread and low reddening, Reticulum is an ideal laboratory for testing stellar pulsation models and calibrating population II distance indicators. We present homogeneous multi-epoch near-infrared (NIR, JHKs) observations of RR Lyrae vari…

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astro-ph.GA

The GOLIATH Survey: OVI Absorption Reveals CGM Evolution through the Starburst-to-Quiescent Transition in Massive Galaxies

Derick Flores, Rongmon Bordoloi, Jason Tumlinson, J. Christopher Howk, Nicolas Lehner, Mary Rickel, Benjamin Oppenheimer, Joseph Burchett et al.

We present the GOLIATH survey (Galaxies, Outflows, and the Lifecycle of Immense, Active, Transforming Halos), a study of the multiphase circumgalactic medium (CGM) of massive ($\langle\log M_\star/M_\odot\rangle \approx 11$), blue ($u-r < 1.65$) starburst and post-starburst galaxies at $\langle z\rangle \approx$ 0.43. This work characterizes the warm-hot CGM through OVI absorption in the inner halo ($R/R_{\rm vir} \leq 0.6$) of these rare systems. Across the star-forming population, OVI column d…

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astro-ph.COastro-ph.GA

Cosmic CORALS: Timing the Universe with high-z star clusters

Elena Tomasetti, Martin Millon, Licia Verde, Frédéric Courbin, Raul Jimenez, Michele Moresco, Carmela Lardo, Andrea Cimatti et al.

In this work, we explore the potential of anchoring the age-redshift relation across cosmic time by probing the oldest star clusters at high redshift, now observed thanks to the James Webb Space Telescope in strongly lensed fields. As a case study, we consider one of the highest-redshift systems observed, the Cosmic Gems arc at $z=9.625$. We perform image deconvolution of multi-band JWST imaging, identifying a total of 20 point sources along the arc. We derive the stellar ages through a cosmolog…

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astro-ph.GAastro-ph.CO

The first dusty galaxies across $6 \lesssim z \lesssim 14$: Blue monsters, red monsters, and the bimodality of dust content in early galaxies

Sergio Martínez-González, Casiana Muñoz-Tuñón, Santiago Jiménez

JWST has revealed galaxies at $z>10$ with extremely blue UV-continuum slopes approaching $β_{\rm UV}\lesssim-2.4$, and low inferred dust contents. At similar redshifts, JWST and ALMA reveal dusty massive systems reaching $β_{\rm UV}\gtrsim-1$. We aim to explain blue monsters and red monsters at $z\gtrsim10$ as different outcomes of supernova dust retention in clustered star-forming systems and connect this bimodality to dusty massive galaxies at $z\simeq6$--7. We model dust removal in a cluster-…

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astro-ph.IMastro-ph.COcs.CVstat.ML

Strong Gravitational Lensing Posterior Sampling in Pixel-Space Using Diffusion Models and Recurrent Inference Machines

Guillaume Payeur, Laurence Perreault-Levasseur, Gabriel Missael Barco, Yashar Hezaveh

Modeling galaxy-galaxy strong gravitational lenses to infer the brightness of the source galaxy and the mass distribution of the foreground galaxy is computationally challenging, particularly for high-resolution, high signal-to-noise ratio observations. In this regime, high-dimensional representations of both the source and the foreground mass distribution are necessary to model the data down to the noise level. This inference problem has been challenging for both traditional and machine learnin…

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astro-ph.HEgr-qc

Gravitational-Wave Sky Mapping with Pulsar Timing Arrays: The Full Earth-Pulsar Response and Fundamental Resolution Limits

S. A. Andrianov, S. M. Kopeikin

Pulsar timing arrays (PTAs) are the only means to observe nanohertz gravitational waves (GWs). While current analyses primarily exploit the Earth term, the full detector response encodes additional directional information in the pulsar terms. We develop a GW sky-mapping framework based on the complete Earth--pulsar response and a tensor spherical harmonic decomposition of the GW field. This yields closed-form response functions for an elementary baseline and casts PTA sky reconstruction as a lin…

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astro-ph.EP

Refined parameters, formation, and dynamical stability of the wild exoplanet system K2-312=HD 80653

L. Naponiello, E. Poretti, K. Rice, A. S. Bonomo, L. Malavolta, M. Stalport, A. Vanderburg, C. Ziegler et al.

The architecture of planetary systems hosting ultra-short-period (USP) planets is a key diagnostic for understanding formation and migration scenarios. The presence of outer giant companions in these systems is of particular interest to test theories regarding dynamical effects and pebble accretion. We present an extended radial velocity (RV) monitoring of the bright star K2-312=HD80653, known to host a rocky USP super-Earth ($P_b=0.720$d). Previous studies identified a long-term trend and subse…

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hep-exastro-ph.IMquant-ph

Dark matter searches with a 13 meV threshold superconducting sensor array

Christopher Albert, Lanqing Yuan, Jacob Harris, Ritoban Basu Thakur, Andrew Bear, Karl K. Berggren, Christopher Cappiello, Christopher Curwen et al.

Many well-motivated dark matter models predict meV-scale energy deposits in interactions with terrestrial experiments, but this regime is challenging to probe due to a lack of mature single-quantum detectors. Here we report results from QUALIPHIDE (QUAntum LImited PHotons In the Dark Experiment), a cryogenic dark matter search using a $41$-pixel array of energy-resolving microwave kinetic inductance detectors with a $13$ meV threshold, simultaneously used to look for both conversion photons from…

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hep-exastro-ph.IMquant-ph

Dark matter searches with a 13 meV threshold superconducting sensor array

Christopher Albert, Lanqing Yuan, Jacob Harris, Ritoban Basu Thakur, Andrew Bear, Karl K. Berggren, Christopher Cappiello, Christopher Curwen et al.

Many well-motivated dark matter models predict meV-scale energy deposits in interactions with terrestrial experiments, but this regime is challenging to probe due to a lack of mature single-quantum detectors. Here we report results from QUALIPHIDE (QUAntum LImited PHotons In the Dark Experiment), a cryogenic dark matter search using a $41$-pixel array of energy-resolving microwave kinetic inductance detectors with a $13$ meV threshold, simultaneously used to look for both conversion photons from…

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astro-ph.EPphysics.space-ph

Three-Dimensional Dust Distribution in the Jovian System from Juno/Waves Observations: Insights into the Halo Ring and Magnetospheric Dust

Yuqi Zhang, Shengyi Ye, Yuting Li, Wenyue Li, Guangzhou Wang, Xinya Duanmu

Discoveries regarding the dusty rings of Jupiter and the Galilean satellites' dust environment have been continuously refined by orbiters and flybys. Leveraging Juno Waves instrument electric field data, we developed a hybrid recognition framework, coupling Kvammen et al.'s Convolutional Neural Network (CNN) with rule-based differential peak analysis, to systematically map the Jovian dust environment. This automated pipeline successfully identified over 150,000 dust impacts, effectively isolatin…

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gr-qcastro-ph.IMphysics.ins-det

Optomechanical transfer factors for scattered light noise estimations in the beamtubes of ground-based gravitational wave detectors

M. Andrés-Carcasona

Scattered light is a relevant noise source in current ground-based gravitational-wave detectors and a critical design concern for next-generation observatories. Beamtube scattered light estimates usually combine optical propagation simulations with analytical couplings that do not fully propagate the frequency-dependent optomechanical response of the interferometer to the strain readout. In this work, we use improved analytical transfer factors to convert scattered-light field perturbations in t…

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gr-qcastro-ph.HE

GWTC-5.0: Tests of General Relativity

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration, A. G. Abac, A. Abe, I. Abouelfettouh, F. Acernese, K. Ackley et al.

The signals from the LIGO-Virgo-KAGRA network of gravitational-wave (GW) detectors allow us to perform sensitive tests of general relativity (GR) in the dynamical and strong-field regime of gravity. We present the results of seven tests of GR using the observed binary signals in the fifth GW Transient Catalog (GWTC-5.0), i.e., up to and including the second part of the fourth observing run (O4b). We restrict our analysis to the confident signals, henceforth called events, observed by at least tw…

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

Astrophysics on GPUs: introducing AGILE 1.0

Oliver Porth, Adrian Kelly, Olaf Willocx, Hao Wu, Jesse Vos, Yuhao Zhou, Héctor R. Olivares Sánchez, Leon Oostrum et al.

We present AGILE, a GPU-enabled adaptive mesh refinement (AMR) framework for the solution of (near-) conservation laws which occur in astro- and solar-physical applications. AGILE is written in modern fortran 2003, inherits a part of its modules and mesh handling from MPI-AMRVAC, and achieves excellent GPU performance via OpenACC offloading. We here discuss the design decisions which enable AGILE to perform cost-efficient and scalable deeply nested AMR simulations with moderate block sizes of e.…

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astro-ph.GA

The Large Magellanic Cloud through the lens of the James Webb Space Telescope: Binaries and the mass function in the galaxy's outskirts

M. V. Legnardi, F. Muratore, A. P. Milone, G. Cordoni, E. Dondoglio, L. N. Gorza, A. Bellini, F. Calura et al.

Nearby galaxies such as the Large Magellanic Cloud (LMC) offer an ideal laboratory to test the initial mass function under different physical conditions, but previous works have been limited by photometric depth and have therefore poorly constrained the low-mass regime. Here, we analyze ultra-deep James Webb Space Telescope observations of a field in the LMC outskirts, near the intermediate-age and massive star cluster NGC 1846. Using the $m_{\rm F322W2}$ versus $m_{\rm F115W}-m_{\rm F322W2}$ co…

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hep-phastro-ph.HEhep-ex

Astrophysical Neutrino Sources as Colliders

Carlos A. Argüelles, P. S. Bhupal Dev, Bhaskar Dutta, Gonzalo Herrera, Nicholas Kamp, Jason Kumar, Stephan A. Meighen-Berger, Mudit Rai et al.

High-energy neutrinos arise from processes at large center-of-mass energies, offering a window to test physics at comparable scales or beyond those accessible in collider experiments on Earth. Here, we present a recipe for extracting two-sided bounds on the inelastic $pp$ and $pγ$ cross sections from neutrino point-source data, by independently constraining every astrophysical input (cosmic-ray luminosities and target densities) through electromagnetic observations or theoretical arguments. The…

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astro-ph.IM

NAPTIME: A Neural-Process Framework for Rubin Alert Classification

Nicholas Earl, Siddharth Chaini, K. Decker French, Jason T. Hinkle, Yashasvi Moon, Margaret Shepherd

The Vera C. Rubin Observatory Legacy Survey of Space and Time will produce a high-volume stream of irregularly sampled multiband alerts for which spectroscopic confirmation will be available only for a small minority of sources. Tidal disruption events are rare phenomena that provide a direct probe of dormant massive black holes, but their light curves can be confused with nuclear variability and other transient subclasses. We present NAPTIME (Neural Astrophysical Photometric Transient Identific…

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astro-ph.SR

Testing Theories of Solar Coronal Heating with Three-Dimensional Forward Modeling

Steven R. Cranmer, Chris R. Gilly

After almost a century of speculation, the physical processes responsible for heating the Sun's corona remain uncertain. Observations of coronal loops at extreme ultraviolet and X-ray wavelengths have provided substantial insights, such as the constraint that heating rates increase monotonically with local magnetic field strength. However, there remain dozens of competing suggestions for detailed theoretical explanations of the heating. There remains a need to compare the predictions of these th…

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astro-ph.SRastro-ph.HE

Will a Supernova explode in CD-30°11223?

L. Piersanti, L. R. Yungelson, E. Bravo, I. Dominguez

Context: Accretion of He-rich matter onto a low mass carbon-oxygen white dwarf in a binary system with a He-rich donor may lead to an explosive event of Supernova Ia proportion, though with low peak luminosity and peculiar nucleosynthesis. Recently such a statement has been questioned, suggesting that, if the effects of rotation are accounted for in the evolution of the accretor, the latter does not explode, but it becomes a white dwarf with a massive He-buffer. Aims: We investigate the expected…

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nucl-thastro-ph.HEhep-phnucl-ex

Quarkyonic Stars with Strangeness

Jin-Biao Hu, Jun-Ting Ye, Si-Pei Wang, Rui Wang, Zhen Zhang, Lie-Wen Chen

We propose an extension of the quarkyonic matter framework that includes $u$, $d$, and $s$ quarks and the full baryon octet. Within this extended framework, we impose beta-equilibrium between baryons and leptons, while determining the quark fractions from the constituent quark contents of baryons. The hadronic sector of octet baryons is described by a recently developed density, momentum and isospin dependent effective interaction based on the N3LO Skyrme pseudopotential, whereas quarks and lept…

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astro-ph.SR

Identifying and Determining Atmospheric Parameters of BHB Stars Based on LAMOST DR11

Xiao-Long Wang, Wen-Yuan Cui, Jie Ju, Guo-Zhen Hu, Min Fang, Shuai Zhang, Jia-Ming Liu

Large catalogs of blue horizontal-branch (BHB) stars are essential for studying substructures and kinematics of the Galactic halo. And accurate determination of atmospheric parameters for BHB stars provides insight into stellar evolution. In this work, we perform a systematic search for BHB stars based on LAMOST DR11, and identify $13\,988$ BHB spectra, corresponding to $10\,236$ unique BHB stars. We estimate an identification rate of $\sim80\%-90\%$, and a contamination rate of $\lesssim10\%$ f…

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astro-ph.SR

Determination of the horizontal velocity field in the solar atmosphere: Method validation using 3D MHD model

Andrii Prysiazhnyi, Oleksandra Baran

We present an improved version and further validation of a method, originally introduced by Stodilka (2016), for reconstructing horizontal velocity fields in the solar atmosphere from physical parameters typically derived from spectroscopic observations through inversion techniques. This approach relies on the continuity equation and the assumption of negligible vertical vorticity. Several algorithmic modifications were implemented to allow application to large spatial grids, including the compa…

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astro-ph.GA

Physical Properties of 6.7 Million Galaxies from the DESI Bright Galaxy Survey: Spectral Fitting and Systematic Tests with Mock Spectra

Niu Li, Hu Zou, Jinfu Gou, Weijian Guo, Wenxiong L, Haoming Song, Jipeng Sui, Xi Tan et al.

We present a comprehensive analysis of the physical properties of galaxies in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1) Bright Galaxy Survey (BGS), based on full spectral fitting of $\sim 6.7$ million galaxy spectra. Using a customized spectral fitting pipeline, we derive key physical parameters including stellar mass, stellar velocity dispersion, stellar population age, dust attenuation, and emission-line properties. To quantify the reliability and systematic uncertai…

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astro-ph.SR

Optical Spectroscopy and Temporal Evolution of the Nova V1405 Cas

Gesesew R. Habtie, Ramkrishna Das, Elias Aydi, Pavol A. Dubovsky

This paper presents the findings from our study of nova V1405~Cas over the first 1051 days after the outburst. The study includes an analysis of the photometric light curve evolution, along with a detailed spectroscopic evolution. Photometric analysis shows that the nova is a very slow nova, with a decline timescale of $t_2 \approx 165$ days. The mass of the white dwarf is calculated as \( M_{\rm WD} \sim 0.7M_{\odot} \). The secondary star is a low-mass main-sequence star, with a mass of \( M_{…

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