Results 1 to 10 of about 30,505 (211)

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
exaly   +6 more sources

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, Hincelin U, Bergeat A, Costes M, Loison JC, Wakelam V, Hickson KM.   +6 more
europepmc   +6 more sources

CN and HCN in Dense Interstellar Clouds [PDF]

The 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.
Amiel Sternberg, Bachiller R., Bachiller R., de Boisanger C., Flower D. R., Fuente A., Gai I. Boger, Greaves J. S., Herbst E., Jansen D. J., Le Bourlot J., Le Bourlot J., Lee H.-H., Lindqvist M., Messing I., Pineau des Forets G., Schilke P., Simon R., Storzer H., Truong-Bach, Viala Y. P., Vikor L.   +21 more
core   +3 more sources

Interstellar dust charging in dense molecular clouds: cosmic ray effects [PDF]

The Astrophysical Journal, 2015
The local cosmic-ray (CR) spectra are calculated for typical characteristic regions of a cold dense molecular cloud, to investigate two so far neglected mechanisms of dust charging: collection of suprathermal CR electrons and protons by grains, and ...
Caselli, Paola, Galli, Daniele, Ivlev, Alexei, Padovani, Marco   +3 more
core   +6 more sources

Methanetetrol and the final frontier in ortho acids [PDF]

Nature Communications
The 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, Xilin Bai, Anatoliy A. Nikolayev, Qi’ang Gong, Mason McAnally, Jia Wang, Yang Pan, Ryan C. Fortenberry, Alexander M. Mebel, Tao Yang, Ralf I. Kaiser   +10 more
doaj   +2 more sources

Laboratory infrared spectra and fragmentation chemistry of sulfur allotropes [PDF]

Nature Communications
Sulfur 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, Giel Berden, Britta Redlich, Laurens B. F. M. Waters, Joost M. Bakker   +4 more
doaj   +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, Hiroshi Hidaka, W. M. C. Sameera, Yasuhiro Oba, Naoki Watanabe   +4 more
doaj   +1 more source

The Role of Terahertz and Far-IR Spectroscopy in Understanding the Formation and Evolution of Interstellar Prebiotic Molecules

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, Duncan V. Mifsud, Perry A. Hailey, Alejandra Traspas Muiña, Olivier Auriacombe, Nigel J. Mason, Sergio Ioppolo   +6 more
doaj   +1 more source

Diffuse interstellar band formation in dense clouds [PDF]

Astrophysics and Space Science, 1974
Measurements of the strengths of the diffuse interstellar bands at 4430, 5780 and 5797 A show that the bands tend to be weak with respect to extinction in dense interstellar clouds. Data on 10 stars in the Q Ophiuchi cloud complex show further that the diffuse band-producing efficiency of the grains decreases systematically with increasing grain size ...
Snow, Theodore P., Jr., Cohen, Judith G.
openaire   +5 more sources