Results 41 to 50 of about 4,557 (177)

Cosmogenic 10Be as a Tracer for Recent Heliospheric Encounters With Interstellar Cold Clouds and Nearby Supernovae

Geophysical Research Letters, Volume 53, Issue 19, 16 October 2026.
Abstract Recent works suggest there are periods when the Sun encountered massive interstellar cold clouds which compressed the heliosphere to within Earth's orbit, exposing Earth to interstellar galactic cosmic rays and energetic particles of heliospheric origin.
Anna Nica, Merav Opher, Jesse A. Miller, Jennifer L. Middleton, Joe Giacalone   +4 more
wiley   +1 more source

Metallicity Dependence of Molecular Cloud Hierarchical Structure at Early Evolutionary Stages

The Astrophysical Journal, 2023
The formation of molecular clouds out of H i gas is the first step toward star formation. Its metallicity dependence plays a key role in determining star formation throughout cosmic history.
Masato I. N. Kobayashi, Kazunari Iwasaki, Kengo Tomida, Tsuyoshi Inoue, Kazuyuki Omukai, Kazuki Tokuda   +5 more
doaj   +1 more source

CF⁺ excitation in the interstellar medium

Astronomy & Astrophysics, 2020
The detection of CF+ in interstellar clouds potentially allows astronomers to infer the elemental fluorine abundance and the ionization fraction in ultraviolet-illuminated molecular gas. Because local thermodynamic equilibrium (LTE) conditions are hardly fulfilled in the interstellar medium (ISM), the accurate determination of the CF+ abundance ...
Benjamin Desrousseaux, François Lique, Javier R. Goicoechea, Ernesto Quintas-Sánchez, Richard Dawes   +4 more
openaire   +5 more sources

Deuterium enrichment of the interstellar medium [PDF]

New Astronomy, 2015
Despite low elemental abundance of atomic deuterium in interstellar medium (ISM), observational evidences suggest that several species in gas-phase and in ices could be heavily fractionated. We explore various aspects of deuterium enrichment by constructing a chemical evolution model in gas and grain phases.
Das, Ankan, Majumdar, Liton, Chakrabarti, Sandip K., Sahu, Dipen   +3 more
openaire   +2 more sources

Controlled Formation and Unusual Reactivity of Cyanohexatriyne (HC7N), a Synthetically Challenging Interstellar Cyanopolyyne

Chemistry – A European Journal, Volume 32, Issue 38, 13 October 2026.
First controlled formation of cyanohexatriyne (HC7N) is achieved using a cobalt–alkyne masking strategy that overcomes the intrinsic instability of nitrile‐substituted polyynes. The approach enables spectroscopic validation of HC7N and reveals its pronounced electrophilicity through a selective conjugate addition with diethylamine.
Léa Lefrançois, Mano Cremer, Thierry Roisnel, Jean‐Claude Guillemin, Yann Trolez   +4 more
wiley   +1 more source

Studying Magnetic Reconnection with Synchrotron Polarization Statistics

The Astrophysical Journal
Magnetic reconnection is a fundamental process for releasing magnetic energy in space physics and astrophysics. At present, the usual way to investigate the reconnection process is through analytical studies or first-principle numerical simulations. This
Jian-Fu Zhang, Shi-Min Liang, Hua-Ping Xiao   +2 more
doaj   +1 more source

Chemical Kinetics of 2‐, 4‐, and 2,4‐Seleno‐Uracils at Low Temperatures: Tautomerizations and Rotamerizations on Inert Matrices

International Journal of Chemical Kinetics, Volume 58, Issue 10, Page 881-889, October 2026.
ABSTRACT In the interstellar medium, chemical reactions proceed under conditions vastly different to those on Earth; these include extremely low temperatures and densities and take place in the gas phase and on water–ice grains. Understanding the energetics and more importantly the kinetics of such reactions is of relevance to the consequences on how ...
Judith Wurmel, John M. Simmie
wiley   +1 more source

Marginally Stable Nuclear Burning Triggered at Different Depths of the Neutron Star Surface in Low-mass X-Ray Binary 4U 1608-52

The Astrophysical Journal
We investigated the timing and spectral properties of the millihertz quasiperiodic oscillations (mHz QPOs) in the neutron star low-mass X-ray binary 4U 1608–52 using NICER observations. Our analysis reveals a correlation between the QPO frequency and its
Ming Lyu, Guobao Zhang, Mariano Méndez, Huaping Xiao   +3 more
doaj   +1 more source

From Flybys to Sample Return: A Review of Space Probes and Robotic Sampling Technologies for Small Bodies

Journal of Field Robotics, Volume 43, Issue 7, Page 4475-4514, October 2026.
ABSTRACT As a crucial puzzle piece of deep space exploration, exploring small bodies can provide significant scientific insights and valuable mineral resources. Unlike missions to the Moon and Mars, small‐body missions pose distinct technical challenges, including communication delays, weak gravity, and uncertain environments. This paper reviews a full
Xin Zhang, Hao Zhou, Dalin Zhou, Zhaojie Ju   +3 more
wiley   +1 more source

Revealing the Spectral Properties of Magnetic Turbulence by Synchrotron Polarization Gradients

The Astrophysical Journal
Based on the modern understanding of MHD turbulence theory, we propose a new method for measuring the spectral properties of magnetic turbulence by synchrotron polarization gradient analysis.
Jian-Fu Zhang, Zi-Qi Liu
doaj   +1 more source