Revisiting the Formation of HeH+ in the Planetary Nebula NGC 7027
Abstract
From four independent calculations using three different theoretical approaches, rate coefficients for the formation of HeH+ via the radiative association of He+ and H were computed. Good agreement is found between our new calculations and prior results obtained two decades ago for kinetic temperatures between ∼800 and 20,000 K. This finding is inconsistent with a recent claim in the literature of a wide variation in published values and establishes the robustness of our knowledge of this process for the formation of HeH+. The implications of the current results to the first detection of HeH+ and its modeled abundance in the planetary nebula NGC 7027 are discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2020
- DOI:
- 10.3847/1538-4357/ab9a50
- arXiv:
- arXiv:2006.08716
- Bibcode:
- 2020ApJ...898...86F
- Keywords:
-
- Molecular physics;
- Molecule formation;
- 2058;
- 2076;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- etable of rate coefficients available