Atomic and Molecular Processes in the Early Universe

Lepp, S.

doi:10.1063/1.1928873

Cited by 4 publications

(3 citation statements)

References 74 publications

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“…During several decades, it was thought that noble gas compounds were quite unlikely, as they would react with other elements or molecular systems through weak van der Waals (vdW) interactions. Such proton-noble gas molecules are produced primarily in the ISM and the planetary ionospheric, and they are critical to understand and model the scenario of the early universe (Zygelman et al, 1998 ; Ferriére, 2001 ; Lepp et al, 2002 ).…”

Section: Introductionmentioning

confidence: 99%

Computational Characterization of Astrophysical Species: The Case of Noble Gas Hydride Cations

Oca-Estévez

Prosmiti

2021

Front. Chem.

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Theoretical–computational studies together with recent astronomical observations have shown that under extreme conditions in the interstellar medium (ISM), complexes of noble gases may be formed. Such observations have generated a wide range of possibilities. In order to identify new species containing such atoms, the present study gathers spectroscopic data for noble gas hydride cations, NgH+ (Ng = He, Ne, Ar) from high-level ab initio quantum chemistry computations, aiming to contribute in understanding the chemical bonding and electron sharing in these systems. The interaction potentials are obtained from CCSD(T)/CBS and MRCI+Q calculations using large basis sets, and then employed to compute vibrational levels and molecular spectroscopic constants for all known stable isotopologues of ground state NgH+ cations. Comparisons with previously reported values available are discussed, indicating that the present data could serve as a benchmark for future studies on these systems and on higher-order cationic noble gas hydrides of astrophysical interest.

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Section: Introductionmentioning

confidence: 99%

Computational Characterization of Astrophysical Species: The Case of Noble Gas Hydride Cations

Oca-Estévez

Prosmiti

2021

Front. Chem.

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“…Ion chemistry also plays a large role in formation of H 2 , which is crucial for cooling of the denser clumps formed in the primeval clouds, which were formation sites of the first stars in the early universe. Without any cooling process, the temperature (and, concomitantly, the pressure) of the clumps would increase during collapse through conversion of kinetic into thermal energy until the collapse stops and star formation is halted . Cooling can happen through rotational excitation and subsequent radiative deactivation of the H 2 molecules, allowing these clumps to continue to collapse to form the first massive (Population III) stars (atomic hydrogen is a very inefficient cooling agent below 8000 K, the temperature corresponding to the Lyman alpha line) .…”

Section: Importance Of Ion Reactions In Astronmical Objectsmentioning

confidence: 99%

Experimental Investigations into Astrophysically Relevant Ionic Reactions

Geppert

Larsson

2013

Chem. Rev.

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Introduction 8872 2. Importance of Ion Reactions in Astronmical Objects 8873 2.1. Chemistry of the Early Universe 8873 2.2. Diffuse Clouds 8874 2.3. Dark Clouds 8875 2.4. Prestellar Cores and Protostars 8877 2.5. Protoplanetary Disks 8879 2.6. Circumstellar Envelopes 8881 2.7. Planetary Atmospheres and Ionospheres 8881 2.7.1. Rocky Planets 8881 2.7.2. Gaseous Planets 8883 2.7.3. Satellites of Gaseous Planets 8884 2.8. Conclusion 8886 3. Experimental Challenges To Investigate Ion Reactions 8887 4. Ionic Reactions 8888 4.1. Ion−Electron Reactions 8888 4.2. Ion−Neutral Reactions 8894 4.3.

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“…After emergence of the neutral atoms formation of the first molecules begins. This process is widely studied (in particular, [8,9,10,11,13,16,19,22,26,25,32,33]) because of its importance for cooling of the gas clouds from which the first luminous objects have formed.…”

Section: Introductionmentioning

confidence: 99%

Molecules in the early universe

Novosyadlyi¹,

Sergijenko²,

Shulga³

2017

Kinemat. fiz. nebesnyh tel (Online)

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We study the formation of first molecules, negative Hydrogen ions and molecular ions in model of the Universe with cosmological constant and cold dark matter. The cosmological recombination is described in the framework of modified model of the effective 3-level atom, while the kinetics of chemical reactions in the framework of the minimal model for Hydrogen, Deuterium and Helium. It is found that the uncertainties of molecular abundances caused by the inaccuracies of computation of cosmological recombination are about 2-3%. The uncertainties of values of cosmological parameters affect the abundances of molecules, negative Hydrogen ions and molecular ions at the level of up to 2%. In the absence of cosmological reionization at redshift z = 10 the ratios of abundances to the Hydrogen one are 3.08×10 −13 for H − , 2.37×10 −6 for H 2 , 1.26×10 −13 for H + 2 , 1.12×10 −9 for HD and 8.54 × 10 −14 for HeH

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Atomic and Molecular Processes in the Early Universe

Cited by 4 publications

References 74 publications

Computational Characterization of Astrophysical Species: The Case of Noble Gas Hydride Cations

Computational Characterization of Astrophysical Species: The Case of Noble Gas Hydride Cations

Experimental Investigations into Astrophysically Relevant Ionic Reactions

Molecules in the early universe

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