Astrophysics
NGC 6553's In-Situ Bulge Origin Confirmed via Multi-Element Chemical DNA Fingerprinting
The BulCO survey uses CRIRES/VLT near-infrared spectroscopy to chemically fingerprint 17 stellar systems in the Milky Way bulge. For NGC 6553, abundance measurements of 18 elements across 14 red giant branch stars confirm it as one of the most metal-rich globular clusters in the Galaxy ([Fe/H] = −0.…
Short EHT Baselines Reveal Large-Scale Jet Emission in M87* via Closure Phase Moments
The Event Horizon Telescope's long baselines resolve compact black hole structure but are blind to extended, large-scale jet emission — a known flux recovery problem. This paper introduces a technique exploiting "trivial" closure phases from nearly co-located EHT station pairs, which become non-zero…
Dust Obscuration Biases Stellar Mass Estimates in z~3 SMGs, Revealing Compact Intrinsic Morphologies
JWST/NIRCam and MIRI observations of z~3 SMGs combined with ALMA imaging enable kpc-scale resolved SED fitting, uncovering a resolved star-forming main sequence tying SFR and stellar mass surface densities. Integrated SED fits underestimate stellar mass due to spatially varying dust attenuation, ter…
Milky Way's Last Major Merger Dated to 11.2 Gyr Ago, Linking GSE, Globular Clusters, and ω Centauri Remnant
A robust method using subgiant star ages dates the Gaia-Sausage-Enceladus (GSE) merger to ~11 Gyr ago, coinciding with the Tainá starburst at 11.2 ± 0.1 Gyr that birthed coeval in-situ globular clusters (GCs). GSE's metal-rich GCs formed at 10.9 ± 0.1 Gyr during merger interactions, with ω Centauri …
GOTO’s Rapid Transient Discovery Pipeline and Workflow
The Gravitational-wave Optical Transient Observer (GOTO) has developed a low-latency data pipeline and workflow for prompt discovery and characterization of astrophysical transients. This system utilizes a network of telescopes and difference imaging analysis to identify celestial events within appr…
Sgr C: Supernova Remnant Drives Star Formation
Analysis of [CII] emission in Sagittarius C (Sgr C) reveals an expanding ring-like shell with a dynamic age of 0.13 Myr and an expansion velocity of 23 km/s. This expansion, likely driven by a buried supernova rather than stellar winds, is spatially correlated with a non-thermal radio filament. This…
Protoplanetary Dust Traps are Leakier Than Previously Assumed
New research utilizing the DustPy code challenges previous assumptions about the efficacy of dust traps in protoplanetary disks. A large parameter study reveals that these traps are generally leakier than thought, implying that dust transport into the inner disc and subsequent chemical diversity are…
Euclid Data Reveals Dual AGN in Low-Mass Galaxies
The first Euclid Quick Data Release, combined with multi-wavelength observations, has identified the first spectroscopically confirmed dual active galactic nuclei (AGN) candidates in low-mass galaxies (stellar masses < 10^10 M☉). These findings support hierarchical galaxy evolution models and provid…
JWST Reveals Half of Strong CIII] Emitters at z=5–7 Host AGN, with Dramatic Redshift Evolution in Line Strength
Using JWST/NIRSpec prism data from CEERS, JADES, RUBIES, and CAPERS, this study classifies 61 CIII]λ1907,1909-emitting galaxies at z=5–7 and finds that at least 29 (≈48%) show secure AGN signatures via UV/optical diagnostics or broad Balmer lines. The CIII] equivalent width (EW) at z=5–7 has a media…
Star Formation, Not AGN, Drives Extreme Emission Lines in Early Universe Galaxies
A JWST NIRSpec spectroscopic study of photometrically selected extreme emission-line galaxies (EELGs) in the CEERS field — drawing on CAPERS, RUBIES, THRILS, and CEERS surveys — finds that AGN are not the dominant source of extreme ionizing radiation in the early Universe. While ~10% of photometrica…
Clump Surface Density Drives Core Fragmentation in Massive Star Formation
ALMAGAL survey of 1007 massive clumps reveals fragmentation into 6348 cores correlates strongly with clump surface density, not total mass, supporting density-driven fragmentation on ~0.1 pc scales. The mass of the most massive core and core formation efficiency increase by an order of magnitude acr…
Dense Core Spatial Evolution in Cluster-Forming Clumps Reveals Jeans-Scale Fragmentation and Emerging Mass Segregation
ALMAGAL survey of 514 massive clumps shows dense cores typically form elliptical groups with axis ratio ~2.2 and single characteristic separations matching the thermal Jeans length, though young clumps exhibit wider ~3x Jeans spacing. Core separations decrease from ~22,000 au in early stages to ~7,0…
Discovery of a Dirty Fireball: EP241113a Challenges GRB Paradigms
The Einstein Probe detected an extragalactic fast X-ray transient, EP241113a, exhibiting characteristics consistent with a "dirty fireball." This observation provides the first empirical evidence of such a phenomenon, challenging existing models of relativistic fireballs with high baryon contaminati…
Helium Detected in Type Ic Supernova 2014L via Near-Infrared Spectroscopy
This research confirms the presence of helium in the Type Ic supernova (SN Ic) 2014L, challenging the classification criterion of helium absence in optical spectra. By employing a deep-learning emulator for SN Ic spectra within a Bayesian inference framework, the study quantifies helium mass and out…
sntools Enhanced for Pre-Supernova Neutrino Detection
The sntools neutrino event generator, originally for supernova burst neutrinos, has been updated to include pre-supernova neutrino models. This enhancement aims to provide a unified framework for studying these neutrinos in current and future detectors. The modifications emphasize optimized time bin…
Magnetic White Dwarfs Could Explain "Missing" Period Bouncers
Astronomers have identified ZTF J021804.16+071152.93, a detached binary system comprising a magnetic white dwarf and a brown dwarf, with a 1.7-hour orbital period. This system challenges age estimations based on white dwarf parameters, suggesting past accretion. This discovery aligns with the theory…
Challenging Cataclysmic Variable Donor Star Models
Analysis of the eclipsing cataclysmic variable CSS131106 J052412+004148 reveals unusual donor star properties. The donor is significantly undersized and cooler for its mass compared to expected models, a characteristic shared by two other long-period CVs. This discrepancy suggests current models for…
Gravitational Wave Observations Continue to Uphold General Relativity
Analysis of 91 confident gravitational wave signals from compact binary coalescences, including data from LIGO Virgo KAGRA's O4a run, continues to validate General Relativity (GR). The study examined parameterized deviations across eight tests, finding no evidence for physics beyond GR. These result…
New Limits on Continuous Gravitational Waves from Supernova Remnants
The LIGO-Virgo-KAGRA Collaboration performed directed searches for continuous gravitational waves from 15 supernova remnants. Utilizing five distinct analysis pipelines, the study analyzed data from the first eight months of the fourth observing run (O4). No gravitational wave signals were detected,…
New Limits on Continuous Gravitational Waves from Pulsars
The LIGO-Virgo-KAGRA Collaboration performed narrowband searches for continuous gravitational waves (CWs) from 34 known pulsars using data from the first two parts of their fourth observing run. This search, utilizing a 5n-vector narrowband pipeline with expanded parameter space coverage to include …
Dark Matter Halo Geometry Influences Tidal Structure Morphology and Classification
Dark matter halo geometry significantly influences the morphology and classification of tidal structures, challenging traditional visual inspection methods. Projections of flattened haloes can cause shell-like structures to appear stream-like, leading to misclassifications. A clustering-based framew…
Upgraded Schwarzschild-Couder Telescope Camera Module Demonstrates Enhanced Performance for Gamma-Ray Observation
The prototype Schwarzschild-Couder Telescope (pSCT) camera has undergone a significant upgrade, expanding its focal plane to 11,328 silicon photomultiplier (SiPM) pixels across 177 modules. The upgraded electronics are designed to mitigate crosstalk and noise. Performance testing of a preproduction …
Quantum Information Processing for Enhanced Gravitational Microlensing Time Delay Measurement
A novel method combining quantum-inspired algorithms and quantum information processing dramatically reduces the photon requirement for measuring gravitational microlensing time delays. This advancement enables observations previously impossible due to photon flux and signal coherence constraints. T…
Reduced Significance of CMB Anomalies with Improved Foregrounds
Improved foreground cleaning methods and minimal sky masking (1%) significantly reduce the statistical significance of two out of five commonly studied Cosmic Microwave Background (CMB) anomalies, specifically the low real-space correlation function and local-variance asymmetry. While other anomalie…
New CMB Analysis Confirms Low-Multipole Anomalies and Refines Cosmological Parameters
A novel analysis of WMAP and Planck CMB data, employing a template-based foreground cleaning approach, has enabled a nearly full-sky recovery of temperature anisotropy at multipoles ℓ<30. This new methodology confirms persistent anomalies such as a low quadrupole power and an overall deficit in powe…
Diamond-Loaded Polyimide Aerogel Filters for Cryogenic Astronomical Instrumentation
This paper demonstrates the utility of conductively-loaded, polyimide aerogel filters for astronomical and planetary science applications. These filters, designed for far-infrared, sub-millimeter, and microwave regimes, exhibit mechanical stability at cryogenic temperatures and perform within the re…