SAMOP 2023 – scientific programme
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MO: Fachverband Molekülphysik
MO 13: Poster II
MO 13.2: Poster
Wednesday, March 8, 2023, 16:30–19:00, Empore Lichthof
Merged-beams experiments on molecular ion-neutral reactions for astrochemistry — •Pierre-Michel Hillenbrand1, Xavier Urbain2, and Daniel Wolf Savin3 — 1Justus-Liebig Universität, Giessen, Germany — 2Université catholique de Louvain, Louvain-la-Neuve, Belgium — 3Columbia University, New York, USA
The gas-phase formation of complex molecules in the interstellar medium proceeds dominantly through barrierless ion-neutral reactions at typical temperatures of 10−100 K. Our merged-beams apparatus at Columbia University in New York City enables us to measure energy-dependent absolute cross sections of molecular formation processes for reactions of singly-charged molecules with neutral atoms and derive temperature-dependent thermal rate coefficients for individual product channels. Focusing on key reactions implemented in astrochemical models as well as on systems of fundamental interest, we have recently studied the reactions
D+H3+→ H2D+ + H [1],
D+H2D+→ D2H+ + H and D+D2H+→ D3+ + H [2],
C+H2+→ CH+ + H and C+D2+→ CD+ + D [3],
O+H3+→ OH+ + H2 and
O+H3+→ H2O+ + H [4].
For example, the branching ratio for the two product channels of the O+H3+ reaction is relevant for accurately modeling the gas-phase formation of water in the diffuse and dense molecular clouds.
[1] Astrophys. J. 877, 38 (2019).
[2] J. Chem. Phys. 154, 084307 (2021).
[3] Phys. Chem. Chem. Phys. 22, 27364 (2020).
[4] Astrophys. J., 927, 47 (2022).