Theoretical and Laboratory Studies on the Interaction of Cosmic‐Ray Particles with Interstellar Ices. II. Formation of Atomic and Molecular Hydrogen in Frozen Organic Molecules

1997 ◽  
Vol 484 (1) ◽  
pp. 487-498 ◽  
Author(s):  
R. I. Kaiser ◽  
G. Eich ◽  
A. Gabrysch ◽  
K. Roessler
Keyword(s):  
Molecular Hydrogen ◽  
Organic Molecules ◽  
Cosmic Ray ◽  
Laboratory Studies ◽  
Interstellar Ices

A Review on the Quantum Mechanical Calculation of Rotational Constants for Interstellar Organic Molecules

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Khemendra Shukla ◽  
Devendra Singh ◽  
Devesh Kumar
Keyword(s):  
Molecular Hydrogen ◽  
Interstellar Dust ◽  
Organic Molecules ◽  
Rotational Constant ◽  
Quantum Mechanical Calculation ◽  
Quantum Mechanical ◽  
Laboratory Studies ◽  
Interstellar Molecules ◽  
Mechanical Calculation ◽  
Ism Dust

Interstellar medium consists of gas and dust, even no part of galaxy is completely empty and interstellar dust is most crucial constituent of our Galaxy. ISM has extremely low density, 90% of it contains gas mainly atomic or molecular hydrogen, 9% is helium, and the remaining 1% consists of heavier elements. The spectroscopic observations both in absorption and emission in ISM, along with laboratory studies of sample materials, have increased interest in the study of organic molecules in ISM. Dust grains in ISM absorb and emit energy in the microwave and far-IR part of the spectrum. Here we are presenting the comparison between computed and observed rotational constant for interstellar organic molecules like CN, CO, HCN, OCS and so many other identified interstellar molecules.

scholarly journals A study of interstellar aldehydes and enols as tracers of a cosmic ray-driven nonequilibrium synthesis of complex organic molecules

2016 ◽  
Vol 113 (28) ◽  
pp. 7727-7732 ◽  
Author(s):  
Matthew J. Abplanalp ◽  
Samer Gozem ◽  
Anna I. Krylov ◽  
Christopher N. Shingledecker ◽  
Eric Herbst ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Cosmic Ray ◽  
Formation Mechanisms ◽  
Molecular Precursors ◽  
Star Forming ◽  
Star Forming Regions ◽  
Interstellar Ices ◽  
A Chain ◽  
Nonequilibrium Chemistry ◽  
Complex Organic

Complex organic molecules such as sugars and amides are ubiquitous in star- and planet-forming regions, but their formation mechanisms have remained largely elusive until now. Here we show in a combined experimental, computational, and astrochemical modeling study that interstellar aldehydes and enols like acetaldehyde (CH3CHO) and vinyl alcohol (C2H3OH) act as key tracers of a cosmic-ray-driven nonequilibrium chemistry leading to complex organics even deep within low-temperature interstellar ices at 10 K. Our findings challenge conventional wisdom and define a hitherto poorly characterized reaction class forming complex organic molecules inside interstellar ices before their sublimation in star-forming regions such as SgrB2(N). These processes are of vital importance in initiating a chain of chemical reactions leading eventually to the molecular precursors of biorelevant molecules as planets form in their interstellar nurseries.

scholarly journals On the Mechanism of H2 Formation in the Interstellar Medium

1987 ◽  
Vol 120 ◽  
pp. 167-169
Author(s):  
Valerio Pirronello
Keyword(s):  
Interstellar Medium ◽  
Molecular Hydrogen ◽  
Formation Rate ◽  
Cosmic Ray ◽  
Interstellar Clouds ◽  
H2 Formation ◽  
Reduced Mobility

The problem of the formation of molecular hydrogen in interstellar clouds is revisited. the role played by cosmic ray bombardment under certain circumstances is considered mainly in the light of the low formation rate of H2 on grains due to the reduced mobility of adsorbed H atoms on their amorphous surfaces at interstellar temperatures.

Atomic and Molecular Structure

2019 ◽  
pp. 323-358
Author(s):  
P.J.E. Peebles
Keyword(s):  
Molecular Structure ◽  
Ground State ◽  
Molecular Hydrogen ◽  
Energy State ◽  
Cosmic Ray ◽  
Pauli Exclusion Principle ◽  
Exclusion Principle ◽  
Distant Galaxy ◽  
Long Time ◽  
Main Approximation

This chapter assesses some applications drawn from atomic and molecular structure. It deals with the structures of the lighter atoms and the simplest molecule, molecular hydrogen. The main approximation method used here is the energy variational principle, which is a powerful technique for computing the low-lying energies of a system such as an atom or molecule. The chapter then introduces the Pauli exclusion principle, which governs the symmetry of the state vector for a system of identical particles such as electrons. Two general features of the exclusion principle are worth noting. First, although the spins make only a very weak contribution to the Hamiltonians for helium, the lowest energy state with spin one is above the spin zero ground state, which is a considerable difference. Second, an electron arriving as a cosmic ray particle from a distant galaxy has to have a wave function antisymmetric with respect to the local electrons, even though the new electron has been away from us for a long time.

scholarly journals Cosmic Ray Induced Photodestruction of Interstellar Molecules

1989 ◽  
Vol 120 ◽  
pp. 32-37
Author(s):  
R. Gredel ◽  
S. Lepp ◽  
A. Dalgarno ◽  
E. Herbst
Keyword(s):  
Molecular Hydrogen ◽  
Cosmic Ray ◽  
Impact Excitation ◽  
Interstellar Molecules ◽  
Secondary Electrons ◽  
Interstellar Clouds ◽  
Wide Range ◽  
Ultraviolet Photons ◽  
The Impact ◽  
Equilibrium Chemical

AbstractUltraviolet photons are created in the interior of dense interstellar clouds by the impact excitation of molecular hydrogen by secondary electrons generated by cosmic ray ionization. The resulting photodissociation and photoionization rates of a wide range of interstellar molecules are calculated. The effects on the equilibrium chemical composition of dense clouds are briefly discussed.

scholarly journals Abiotic Synthesis of Methane and Organic Compounds in Earth’s Lithosphere

Elements ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Eoghan P. Reeves ◽  
Jens Fiebig
Keyword(s):  
Organic Matter ◽  
Organic Compounds ◽  
Molecular Hydrogen ◽  
Inorganic Carbon ◽  
Organic Molecules ◽  
Laboratory Simulations ◽  
Abiotic Synthesis ◽  
Extensive Analysis ◽  
Isotope Analyses ◽  
Ubiquitous Presence

Accumulation of molecular hydrogen in geologic systems can create conditions energetically favorable to transform inorganic carbon into methane and other organic compounds. Although hydrocarbons with a potentially abiotic origin have been proposed to form in a number of crustal settings, the ubiquitous presence of organic compounds derived from biological organic matter presents a challenge for unambiguously identifying abiotic organic molecules. In recent years, extensive analysis of methane and other organics in diverse geologic fluids, combined with novel isotope analyses and laboratory simulations, have, however, yielded insights into the distribution of specific abiotic organic molecules in Earth’s lithosphere and the likely conditions and pathways under which they form.

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