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Related papers: Rotational Excitation of HC_3N by H_2 and He at lo…

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Utilising previous work by the authors on the spin-coupled rotational cross-sections for electron-CN collisions, data for the associated rate coefficients is presented. Data on rotational, fine-structure and hyperfine-structure transition…

Chemical Physics · Physics 2015-06-16 Stephen Harrison , Alexandre Faure , Jonathan Tennyson

We report quantum-mechanical close-coupling calculations for rotational state resolved cross sections for p-H2+HD collisions. The low temperature limit of p-H2+HD is investigated, which is of significant astrophysical interest in regard to…

Chemical Physics · Physics 2015-06-26 Renat A. Sultanov , Dennis Guster

We use the time-independent quantum-mechanical formulation of reactive collisions in order to investigate the state-to-state $\mathrm{H}^+ + \mathrm{HD} \to \mathrm{D}^+ + \mathrm{H}_2$ chemical reaction. We compute cross sections for…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-10 Maxence Lepers , Grégoire Guillon , Pascal Honvault

Motivated by recent observations with Herschel/PACS, and the availability of new rate coefficients for the collisional excitation of CO (Yang et al. 2010), the excitation of warm astrophysical CO is revisited with the use of numerical and…

Astrophysics of Galaxies · Physics 2015-06-04 David A. Neufeld

Modeling environments that are not in local thermal equilibrium, such as protoplanetary disks or planetary atmospheres, with molecular spectroscopic data from space telescopes requires knowledge of the rate coefficients of rovibrationally…

Atomic Physics · Physics 2023-10-10 Taha Selim , Ad van der Avoird , Gerrit C. Groenenboom

Hydronium (H$_3$O$^+$) was first detected in 1986 in interstellar molecular clouds. It was reported in many galactic diffuse and dense regions, as well as in extragalactic sources. H$_3$O$^+$ plays a major role both in interstellar oxygen…

Astrophysics of Galaxies · Physics 2022-11-16 Sándor Demes , François Lique , Alexandre Faure , Floris F. S. van der Tak

We report the first identification in space of HC$_3$N$^+$, the simplest member of the family of cyanopolyyne cations. Three rotational transitions with half-integer quantum numbers from $J$=7/2 to 11/2 have been observed with the Yebes 40m…

Astrophysics of Galaxies · Physics 2024-07-03 C. Cabezas , M. Agúndez , Y. Endo , B. Tercero , N. Marcelino , P. de Vicente , J. Cernicharo

Cross sections have been computed for rotational transitions of H2, induced by collisions with H atoms, using a recent H - H2 potential calculated by Mielke et al. [1]. These results are compared with those obtained with earlier potentials.…

Astrophysics · Physics 2009-11-11 S A Wrathmall , D R Flower

We present a detailed theoretical study of the rotational excitation of CH$^+$ due to reactive and nonreactive collisions involving C$^+(^2P)$, H$_2$, CH$^+$, H and free electrons. Specifically, the formation of CH$^+$ proceeds through the…

Aim: We present an improved database of temperature dependent rate coefficients for rotational state-to-state transitions in H$_{2}$O + H$_{2}$O collisions. The database includes 231 transitions between the lower $para$- and 210 transitions…

Chemical Physics · Physics 2023-10-19 Bikramaditya Mandal , Dmitri Babikov

Results for quantum mechanical calculations of the integral cross sections and corresponding thermal rate coefficients for para-/ortho-H2+HD collisions are presented. Because of significant astrophysical interest in regard to the cooling of…

Chemical Physics · Physics 2015-05-13 Renat A. Sultanov , Avas V. Khugaev , Dennis Guster

The modelling of emission spectra of molecules seen in interstellar clouds requires the knowledge of collisional rate coefficients. Among the commonly observed species, N$_2$H$^+$ is of particular interest since it was shown to be a good…

Astrophysics of Galaxies · Physics 2015-06-23 François Lique , Fabien Daniel , Laurent Pagani , Nicole Feautrier

A computed line list for hydrogen peroxide, H$_2{}^{16}$O$_2$, applicable to temperatures up to $T=1250$~K is presented. A semi-empirical high accuracy potential energy surface is constructed and used with an {\it ab initio} dipole moment…

Earth and Planetary Astrophysics · Physics 2016-07-05 Ahmed F. Al-Refaie , Oleg L. Polyansky , Roman I. Ovsyannikov , Jonathan Tennyson , Sergei N. Yurchenko

We present the first dataset of collisional (de)-excitation rate coefficients of HCN induced by CO, one of the main perturbing gases in cometary atmospheres. The dataset spans the temperature range of 5-50 K. It includes both state-to-state…

Earth and Planetary Astrophysics · Physics 2025-08-28 Francesca Tonolo , Ernesto Quintas-Sánchez , Adrian Batista-Planas , Richard Dawes , François Lique

The tunneling reaction H$_2$ + D$^-$ $\rightarrow$ HD + H$^-$ was studied in a recent experimental work at low temperatures (10, 19, and 23~K) by Endres {\it et al.}, Phys. Rev. A {\bf 95}, 022706 (2017). An upper limit of the rate…

We employ an accurate, ab initio potential energy surface (PES) which describes the electronic interaction energy between the molecular anion OH$^-$ ($^1\Sigma^+$) and the neutral rubidium atom Rb ($^2S$), to evaluate the elastic and…

Atomic Physics · Physics 2018-07-31 L. González-Sánchez , F. Carelli , F. A. Gianturco , R. Wester

Resonant vibrational and rotation-vibration excitation cross sections for electron-CO scattering are calculated in the 0-10 eV energy range for all 81 vibrational states of CO, assuming that the excitation occur via the 2{\Pi} shape…

Chemical Physics · Physics 2012-08-14 V. Laporta , C. M. Cassidy , J. Tennyson , R. Celiberto

The availability of collisional rate coefficients with H$_2$ is a pre-requisite for interpretation of observations of molecules whose energy levels are populated under non local thermodynamical equilibrium conditions. In the current study,…

Astrophysics of Galaxies · Physics 2015-06-22 F. Daniel , A. Faure , L. Wiesenfeld , E. Roueff , D. C. Lis , P. Hily-Blant

{\bf R}-matrix calculations combined with the adiabatic nuclei approximation are used to compute electron-impact rotiational excitation rates for three closed-shell diatomic cations, HeH$^+$, CH$^+$, ArH$^+$. Comparisons with previous…

Astrophysics of Galaxies · Physics 2015-12-02 James R. Hamilton , Alexandre Faure , Jonathan Tennyson

Our knowledge about the "cold" Universe often relies on molecular spectra. A general property of such spectra is that the energy level populations are rarely at local thermodynamic equilibrium. Solving the radiative transfer thus requires…

Instrumentation and Methods for Astrophysics · Physics 2018-01-23 Jérôme Loreau , François Lique , Alexandre Faure