CHABOT, M.; IDBARKACH, T.; BÉROFF, K.; LE PETIT, F.; WAKELAM, V.

doi:10.1051/0004-6361/202037926

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CHABOT, M.
Institut de Physique Nucléaire d'Orsay [IPNO]

IDBARKACH, T.
Institut de Physique Nucléaire d'Orsay [IPNO]

BÉROFF, K.
Institut des Sciences Moléculaires d'Orsay [ISMO]

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Ce document a été publié dans

Astronomy and Astrophysics - A&A. 2020, vol. 640, p. A115

EDP Sciences

Résumé en anglais

Aims. The aim of this work is to provide semi-empirical branching ratios (BRs) for the kinetic databases used in astrochemistry, such as the KInetic Database for Astrochemistry (KIDA). Our work focuses on the CHy(+) species (y = 2–4) excited by cosmic rays (CR), electrons, and photons (UV), or the intermediate excited complexes CHy(+) resulting from chemical reactions. It also intends to test the sensitivity of benchmark calculations to those new physical inputs in cold quiescent clouds and in photo-dissociation regions (PDRs).Methods. We constructed semi-empirical breakdown curves (BDCs) based on the collision of CHy+ (y = 2–4) projectiles of constant velocity (250 keV uma−1) with He atoms as explained in a previous paper, where BRs for UV, CR, and electronic processing were also derived. The same BDCs were applied to predict BRs for chemical reactions (bi-molecular neutral and ionic reactions, charge exchange). The effect of the new BRs on the chemical composition of cold dark clouds was tested using the time-dependent Nautilus gas-grain model. The same effect on the chemical composition of PDRs was tested using the Meudon PDR code.Results. Branching ratio predictions of the model are found to be in good agreement with available BR measurements for charge exchange reactions and the reaction between C and H3+. The chemistry for both cold clouds and PDRs is found to be not strongly affected by this update of BRs.< Réduire

Mots clés en anglais

astrochemistry

planets and satellites: atmospheres

ISM: abundances

ISM: clouds

DOI

http://dx.doi.org/10.1051/0004-6361/202037926

Project ANR

Nano particules et molécules de haute vitesse, sonde des nano-domaines et nano-objets natifs - ANR-10-EQPX-0023
Physics of the 2 infinities and the origins - ANR-10-LABX-0038
PSI - ANR-16-IDEX-0008

Origine

Importé de hal

Unités de recherche

Laboratoire d'Astrophysique de Bordeaux (LAB) - UMR 5804