Negative / Null Result ReportOpen accessPhysics and Astronomy
Stella Koch Ocker, J. M. Cordes · 2026 · The Astrophysical Journal
Abstract Free electrons in the Galactic interstellar medium (ISM) disperse and scatter coherent radio waves, by amounts that depend on the distance to the radio source. Models of the Galactic electron density are thus widely used to predict distances and scattering of compact radio sources (including pulsars, fast radio bursts, and long-period transients), in addition to mitigating ISM foregrounds in Galactic and extragalactic studies. We use a sample of 171 precise pulsar distances, based entirely on parallaxes and globular cluster associations, as well as scattering measurements of 568 pulsa
View details →Negative / Null Result ReportOpen accessPhysics and Astronomy
Tim Linden, Thong T. Q. Nguyen, Tim M. P. Tait · 2026 · Journal of Cosmology and Astroparticle Physics
Abstract We model and constrain the unique indirect detection signature produced by dark matter particles that annihilate through a U(1) gauge symmetry into dark photons that subsequently decay into three-photon final states. We focus on scenarios where the dark photon is long-lived, and show that γ-ray probes of celestial objects can set strong constraints on the dark matter/baryon scattering cross section that in many cases surpass the power of current direct detection constraints, and in some cases even peer into the neutrino fog.
View details →Negative / Null Result ReportPhysics and Astronomy
Zengyou He, Hao Liang, Zheng Chen et al. · 2020 · IEEE Transactions on Knowledge and Data Engineering
Community detection is a key data analysis problem across different fields. During the past decades, numerous algorithms have been proposed to address this issue. However, most work on community detection does not address the issue of…
View details →Negative / Null Result ReportOpen accessPhysics and Astronomy
Lucie E. Rowland, Mauro Stefanon, R. J. Bouwens et al. · 2026 · Monthly Notices of the Royal Astronomical Society
ABSTRACT Metallicity is a crucial tracer of galaxy evolution, providing insights into gas accretion, star formation, and feedback. At high redshift, these processes reveal how early galaxies assembled and enriched their interstellar medium. In this work, we present rest-frame optical spectroscopy of 12 massive ($\log (M_*/\mathrm{{\rm M}_{\odot }})>9$) galaxies at $z\sim 6$–8 from the Reionization Era Bright Emission Line Survey (REBELS) Atacama Large Millimetre/submillimetre Array (ALMA) large program, observed with the James Webb Space Telescope (JWST) NIRSpec integral field unit spec
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R. Abbasi, M. Ackermann, J. Adams et al. · 2026 · The Astrophysical Journal Letters
Abstract Recently, IceCube reported neutrino emission from the Seyfert galaxy NGC 1068. Using 13.1 yr of IceCube data, we present a follow-up search for neutrino sources in the northern sky. NGC 1068 remains the most significant neutrino source among 110 preselected gamma-ray emitters while also being spatially compatible with the most significant location in the northern sky. Its energy spectrum is characterized by an unbroken power-law with spectral index γ = 3.4 ± 0.2. Consistent with previous results, the observed neutrino flux exceeds its gamma-ray counterpart by at least 2 orders of magn
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S. H. Suyu, Ana Acebrón, C. Grillo et al. · 2026 · Astronomy and Astrophysics
Robust mass modeling of strong-lensing galaxy clusters is crucial for studying cosmology and galaxy evolution. We present and compare seven mass models of the galaxy cluster MACS J0138−2155, constructed using six independent modeling software programs, including parametric and free-form approaches. By conducting a blind analysis where all the mass-modeling teams constructed their models independently without exchanging results, we quantified uncertainties arising from modeling software and assumptions. MACS J0138−2155 is unique as the only cluster found to strongly lens two supernovae (SNe), R
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