abstract = { The scattering cross-sections and corresponding rate coefficients for rotationally inelastic collisions of $^{12}$C$_2$^-$ ($^2 \Sigma_g^+$) with H$_2$ ($^1 \Sigma_g^+$) are presented over a broad range of cold-trap temperatures. They have been calculated using quantum scattering theory that employs a new ab initio potential energy surface. The rate coefficients for the inelastic processes in the anionic partner are used to model the thermalisation dynamics of $^{12}$C$_2$^-$ using H$_2$ as a buffer gas, a trap partner which is found here to be far more efficient than the typical buffer gas He and even more so than when using Ar as a partner gas. The microscopic physics underlying these findings is discussed in some detail. We additionally compute and discuss $^{12}$C$_2$^-$ quadrupole transitions by spontaneous emission and use the newly computed rates to show that the anion's rotational levels should be in local thermal equilibrium at typical interstellar conditions.
Authors
- Barry P. Mant,
- dr hab. Jan Franz link open in new tab ,
- Roland Wester,
- Francesco Antonio Gianturco
Additional information
- DOI
- Digital Object Identifier link open in new tab 10.1080/00268976.2021.1938267
- Category
- Publikacja w czasopiśmie
- Type
- artykuły w czasopismach
- Language
- angielski
- Publication year
- 2021
