Results 101 to 110 of about 181,166 (278)

A Cosmic Ray Acceleration Mechanism Based on Background Flow Velocity Inhomogeneities Yielding Power-law Spectra

The Astrophysical Journal
In astrophysics, one significant challenge lies in understanding the acceleration of cosmic rays, which leads to the occurrence of a power law. In this article, momentum transport generated by the combined effects of pitch-angle diffusion and background ...
J.-F. Wang, G. Qin
doaj   +1 more source

Gamma-ray signatures of cosmic ray acceleration, propagation, and confinement in the era of CTA

, 2012
Galactic cosmic rays are commonly believed to be accelerated at supernova remnants via diffusive shock acceleration. Despite the popularity of this idea, a conclusive proof for its validity is still missing.
A. Bamba, A. Marcowith, Acharya B. S., Actis M., Aghajani T., CTA Consortium, D. Hadasch, D. F. Torres, E. Bissaldi, E. d. Cea, E. d. Ona, et al., F. Acero, F. Volpe, G. Pedaletti, M. Renaud, O. Reimer, S. Casanova, S. Gabici, Y. Gallant   +19 more
core   +3 more sources

New Li Lidar Observations and Model Simulations: A Window to Anthropogenic Signatures

Geophysical Research Letters, Volume 52, Issue 22, 28 November 2025.
Abstract We present Li lidar observations in the mesopause region above Kühlungsborn, Germany (54°N, 12°E). The lithium layer is mainly formed by meteoric ablation. But lithium has a much higher relative abundance in space debris compared with meteoroids, making it a good indicator of anthropogenic influence in the upper mesosphere.
M. Gerding, R. Wing, W. Feng, J. M. C. Plane, G. Baumgarten   +4 more
wiley   +1 more source

Atomistic Modeling of Methyl Formate and Glycolaldehyde Formation on Interstellar Dirty Ice Mantles via a “Radical + Ice” Mechanism

ChemPlusChem, Volume 90, Issue 11, November 10, 2025.
The presence of interstellar complex organic molecules (COMs) has been baffling astrochemists for a long time. Methyl formate and glycolaldehyde are widely detected but their abundances mismatch kinetic astrochemical model predictions. Here, the formation of these two COMs is characterized onto a mixed ice surface, highlighting the importance of ...
Jessica Perrero, Stefano Pantaleone, Piero Ugliengo, Albert Rimola   +3 more
wiley   +1 more source

A Possible Common Physics Picture Reflected by the Gamma-Ray Emission of the Galactic Center

The Astrophysical Journal
Long-term observations of the Galactic center by Fermi and HESS have revealed a novel phenomenon: the high-energy gamma-ray spectrum from the gamma-ray source HESS J1745-290 exhibits a double power-law structure.
Lin Nie, Yi-Qing Guo, Si-Ming Liu
doaj   +1 more source

Influence of the source distribution on the age distribution of galactic cosmic rays [PDF]

The age distribution of galactic cosmic rays in the diffusion approximation is calculated. The influence of the scale height of the spatial source distribution on the mean age of particles arriving at the solar system is discussed. The broader the source
Lerche, I., Schlickeiser, R.
core   +1 more source

Ultra-High Energy Neutrino Fluxes: New Constraints and Implications

, 2003
We apply new upper limits on neutrino fluxes and the diffuse extragalactic component of the GeV gamma-ray flux to various scenarios for ultra high energy cosmic rays and neutrinos.
, , , , , , , , , , , , , , , , , , , , , , , , , Aloisio R, AMANDA collaboration, ANTARES Collaboration, Balkanov V (BAIKAL Collaboration), Baltrusaitis R M, Barbot C, Barbot C, Berezinsky V S, Berezinsky V S, Berezinsky V S, Blasi P, Chung D J, Clark T A, Cline D B, Dedenko L G, Dmitry V Semikoz, Dokshitzer Yu L, Eberle B, Ellis R K, Fodor Z, Fodor Z, Fodor Z, For a recent review, G nter Sigl, Gorham P W, Gorham P W, Greisen K, Halzen F, Hannestad S, Hou G W, Kachelriess M, Kachelriess M, Kalashev O E, Kalashev O E, Keshet U, Kieda D, Kim H B, Kravchenko I, Kravchenko I, Kuzmin V A, Kuzmin V A, Lee S, Lehtinen N G, Montaruli T (ANTARES Collaboration), Nagano M (ed), Neronov A, Niessen P (the AMANDA Collaboration), Potgieter M S (ed), Resvanis L, Ringwald A, Rubin N, Sasaki M, See, See, See, See, See, See also Ambrosio M (MACRO Collaboration), See Hayashida N, Sigl G, Singh S, Spiering C, Stecker F W, Strong A W, Yoshida S (AGASA Collaboration), Zatsepin G T, Zatsepin G T   +91 more
core   +2 more sources

Effects of Galactic Irradiation on Thermal and Electronic Transport in Tungsten

physica status solidi (b), Volume 262, Issue 11, November 2025.
This atomic‐scale study reveals how low‐to‐mid‐energy space irradiation alters tungsten's thermal and electronic behavior, even at low defect levels. Focusing on vacancy sites in bulk and near grain boundaries, it employs two novel approaches: site‐projected thermal conductivity and the N2$^{2}$ method for the thermal and electronic response analysis ...
Chinonso Ugwumadu, David A. Drabold, Roxanne M. Tutchton   +2 more
wiley   +1 more source

The AMS-02 Cosmic-Ray Deuteron Flux is Consistent with a Secondary Origin

The Astrophysical Journal Letters
The recent measurements of cosmic-ray (CR) deuteron fluxes by AMS-02 show that the rigidity dependence of deuterons is similar with that of protons but flatter than ^3 He, which has been attributed to the existence of primary deuterons with abundance ...
Qiang Yuan, Yi-Zhong Fan
doaj   +1 more source

First Detection of [SI] in Near‐IR JWST Observations of Io in Eclipse, and Comparison With SO Emissions, Evolving Volcanic Eruptions, and Prior UV HST‐STIS [SI] Emissions

Journal of Geophysical Research: Planets, Volume 130, Issue 11, November 2025.
Abstract We observed Io with the James Webb Space Telescope (JWST) NIRSpec/Integral Field Unit (1.0–5.3 μm, R∼2700 $R\sim 2700$) in August 2023 while the satellite was in eclipse. Thermal emission from Kanehekili Fluctus is consistent with the cooling of lava flows after a vigorous eruption in November 2022.
Imke de Pater, Darrell F. Strobel, Ashley Gerard Davies, Joachim Saur, Lorenz Roth, Katherine de Kleer, Emmanuel Lellouch, Zachariah Milby, Carl Schmidt, Thierry Fouchet, Michael H. Wong, Leigh N. Fletcher, Jake Harkett, Michael Roman, Richard J. Cartwright, Jason E. Perry, Julie Renaud‐Kim, Carolyn Jordan, Stephan Schlegel, David A. Williams, David M. Nelson   +20 more
wiley   +1 more source