Results 1 to 10 of about 690 (161)
Elemental nitrogen partitioning in dense interstellar clouds. [PDF]
Proc Natl Acad Sci U S A, 2012 Many chemical models of dense interstellar clouds predict that the majority of gas-phase elemental nitrogen should be present as N 2 , with an abundance approximately five orders of magnitude less than that of hydrogen.
Daranlot J +6 more
europepmc +6 more sources
CN and HCN in Dense Interstellar Clouds [PDF]
Astrophysical Journal, 2005 We present a theoretical investigation of CN and HCN molecule formation in dense interstellar clouds. We study the gas-phase CN and HCN production efficiencies from the outer photon-dominated regions (PDRs) into the opaque cosmic-ray dominated cores. We calculate the equilibrium densities of CN and HCN, and of the associated species C+, C, and CO, as ...
Amiel Sternberg
exaly +3 more sources
The chemistry of phosphorus in dense interstellar clouds
Astrophysical Journal, 1984 Laboratory experiments show that the ion-molecule chemistry of phosphorus is significantly different from that of nitrogen in dense interstellar clouds. The PH3 molecule is not readily formed by gas-phase, ion-molecule reactions in these regions. Laboratory results used in a simple kinetic model indicate that the most abundant molecule containing ...
S S Prasad
exaly +2 more sources
Methanetetrol and the final frontier in ortho acids [PDF]
Nature CommunicationsThe rapid dissociation of methanetetrol (C(OH)4) has been suggested as an impediment to its observation, despite the stability of its substituted derivative orthocarbonates (C(OR)4).
Joshua H. Marks +10 more
doaj +2 more sources
Laboratory infrared spectra and fragmentation chemistry of sulfur allotropes [PDF]
Nature CommunicationsSulfur is one of six life-essential elements, but its path from interstellar clouds to planets and their atmospheres is not well known. Astronomical observations in dense clouds have so far been able to trace only 1 percent of cosmic sulfur, in the form ...
Piero Ferrari +4 more
doaj +2 more sources
Hydrogen Chloride in Dense Interstellar Clouds
Astrophysical Journal, 1974 T De Jong, M Oppenheimer, J H Black
exaly +2 more sources
Glaciations and dense interstellar clouds [PDF]
Nature, 1976 McCREA has revived the idea that the Earth's ice ages may have been caused by the interaction of the Sun with dense interstellar clouds1. In this theory, originally formulated by Hoyle and Lyttleton2, the solar luminosity is temporarily increased by the accretion of gas on to the Sun when the Solar System passes through a dense interstellar cloud.
BRIAN DENNISON, V. N. MANSFIELD
openaire +2 more sources
Presumed Detection of C5 Molecule in the Interstellar Medium
The Astrophysical Journal, 2022 The paper suggests the presence of the carbon chain C _5 molecule in translucent, interstellar H i clouds. This species, the only five atom interstellar molecule, observable in dark, translucent clouds, seems to be observable in reasonably dense clouds ...
J. Krełowski, R. Hakalla, W. Szajna
doaj +1 more source
Determination of the Branching Ratio of CH3OH + OH Reaction on Water Ice Surface at 10 K
The Astrophysical Journal, 2023 The CH _3 O and CH _2 OH radicals can be important precursors of complex organic molecules (COMs) in interstellar dust. The COMs presumably originating from these radicals were abundantly found in various astronomical objects.
Atsuki Ishibashi +4 more
doaj +1 more source
Frontiers in Astronomy and Space Sciences, 2021 Stellar systems are often formed through the collapse of dense molecular clouds which, in turn, return copious amounts of atomic and molecular material to the interstellar medium.
Duncan V. Mifsud +6 more
doaj +1 more source