Astro Physics
JEM-EUSO Collaboration Presents Papers at ICRC 2025 on Ultra-High Energy Cosmic Ray Detection
The JEM-EUSO Collaboration submitted a collection of papers to the 39th International Cosmic Ray Conference (ICRC 2025) in Geneva, Switzerland, from July 14-24, 2025. This arXiv preprint aggregates contributions from over 70 authors, focusing on high-energy astrophysical phenomena and astrophysical …
Weak PBH Clustering Reduces Required Abundance to Explain LIGO-Virgo-KAGRA Mergers
Primordial black holes (PBHs) can form initially clustered populations, altering binary merger rates compared to Poisson distributions. Weak clustering enables LIGO-Virgo-KAGRA events with lower PBH abundance fraction f_PBH in the early two-body merger channel. Stronger clustering suppresses two-bod…
LuSEE-Night Enables Joint Bayesian Estimation of Lunar Subsurface Dielectrics and Galactic Foregrounds
LuSEE-Night, a low-frequency radio telescope landing on the lunar far side in 2027, faces calibration challenges from unknown subsurface dielectric properties that alter the antenna beam by 10-20% via reflections and power absorption. Simulations reveal subsurface variations primarily affect beam pr…
CO2 Ice Albedo Parameterization Boosts Snowball Exit Threshold by 29% for F-Dwarf Eccentric Exoplanets
A 1D energy balance model with CO2 ice albedo parameterization shows eccentric exoplanets around F-dwarfs need 29% higher orbit-averaged flux to escape global water ice cover versus water ice-only models. F-dwarf planets on circular orbits require 30% more flux than M-dwarf counterparts due to highe…
T16 Pipeline Doubles TESS Exoplanet Candidates with 10,000 New Detections from Cycle 1 FFIs Down to 16th Magnitude
The T16 project processed 83.7 million TESS Cycle 1 FFI light curves down to T=16 mag using uniform detrending and systematics correction, enabling a semi-automated ML-assisted transit search that identified 11,554 planet candidates with periods 0.5-27 days. This yielded 10,091 new candidates, inclu…
Multiwavelength Analysis Identifies Flaring Blazar Candidates for 220 PeV Neutrino KM3-230213A
KM3NeT detected a record ~220 PeV neutrino from direction RA 94.3°, Dec -7.8° (J2000), with 99% CL 3° error radius. Seventeen blazar candidates within this region underwent comprehensive multiwavelength scrutiny using new observations and archives across radio to gamma rays. Notable flares include a…
Triggered Star Formation Confirmed by Core Arch and Scales in AG286.0716-1.8229
ALMA observations of ALMAGAL source AG286.0716-1.8229 detect 9 cores, with 8 aligned along a ~0.75 pc radius arch outside an H II region confirmed by SMGPS/RACS radio data showing optically thin free-free emission (spectral index -0.14 to -0.4). Four cores are prestellar candidates based on high-res…
Interstellar Comet 3I/ATLAS Shows Elevated Nitrogen Isotopic Ratio Matching ISM and Outer Protoplanetary Disks
Measurements of CN in interstellar comet 3I/ATLAS yield ¹²C/¹³C = 147₊₈₇⁻⁴₀, marginally higher than solar system comets (~90) and ISM values (~70-100). The ¹⁴N/¹⁵N ratio = 343₊₄₅₄⁻¹²⁴ exceeds typical solar system comet values (~150), aligning closely with ISM, pre-stellar cores, and outer protoplane…