Volume 628, August 2019
|Number of page(s)||15|
|Section||Interstellar and circumstellar matter|
|Published online||08 August 2019|
Breakdown curves of CH2(+), CH3(+), and CH4(+) molecules
I. Construction and application to electron collisions and UV photodissociation
Institut de Physique Nucléaire d’Orsay (IPNO), CNRS, Université Paris Sud, Université Paris-Saclay,
2 Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
3 Université de Toulouse, UPS-OMP, IRAP, 31028 Toulouse cedex 4, France
4 Departamento de Química, Módulo 13, Condensed Matter Physic Center (IFIMAC), Institute for advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
Accepted: 9 June 2019
Aims. The aim of this work is to furnish branching ratios (BRs) to the kinetic databases used in astrochemistry such as the KInetic Database for Astrochemistry (KIDA). This concerns CHy(+) species (y = 2–4) excited by cosmic rays, electrons and photons, or the intermediate excited complexes CHy(+) resulting from a chemical reaction.
Methods. The full set of fragmentation branching ratios following CHy(+) (y = 2,4) of constant velocity (250 keV uma−1) colliding with He atoms has been measured with the multidetector AGAT. Kinetic energy distributions of neutral fragments produced in each dissociation channel have been also measured. With these experimental inputs, and theoretical dissociation energies, semiempirical breakdown curves (BDCs) have been constructed.
Results. Prediction of BRs with the present BDCs is found to agree with available BR measurements for electronic dissociative recombination, collision with fast electron and photodissociation. Dependence of BRs with the various UV fields relevant to interstellar medium and planetary atmospheres is predicted.
Key words: astrochemistry / ISM: molecules / molecular processes
© T. IdBarkach et al. 2019
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.