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Article
CF⁺ Excitation in the Interstellar Medium
Astronomy and Astrophysics
  • Benjamin Desrousseaux
  • François Lique
  • Javier R. Goicoechea
  • Ernesto Quintas-Sánchez, Missouri University of Science and Technology
  • Richard Dawes, Missouri University of Science and Technology
Abstract

The detection of CF+ in interstellar clouds potentially allows astronomers to infer the elemental fluorine abundance and the ionization fraction in ultraviolet-illuminated molecular gas. Because local thermodynamic equilibrium (LTE) conditions are hardly fulfilled in the interstellar medium (ISM), the accurate determination of the CF+ abundance requires one to model its non-LTE excitation via both radiative and collisional processes. Here, we report quantum calculations of rate coefficients for the rotational excitation of CF+ in collisions with para- and ortho-H2 (for temperatures up to 150 K). As an application, we present non-LTE excitation models that reveal population inversion in physical conditions typical of ISM photodissociation regions (PDRs). We successfully applied these models to fit the CF+ emission lines previously observed toward the Orion Bar and Horsehead PDRs. The radiative transfer models achieved with these new rate coefficients allow the use of CF+ as a powerful probe to study molecular clouds exposed to strong stellar radiation fields.

Department(s)
Chemistry
Research Center/Lab(s)
Center for High Performance Computing Research
Keywords and Phrases
  • ISM: general,
  • Masers,
  • Molecular data,
  • Radiative transfer,
  • Scattering
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2020 EDP Sciences, All rights reserved.
Creative Commons Licensing
Creative Commons Attribution 4.0
Publication Date
12-21-2020
Publication Date
21 Dec 2020
Disciplines
Citation Information
Benjamin Desrousseaux, François Lique, Javier R. Goicoechea, Ernesto Quintas-Sánchez, et al.. "CF⁺ Excitation in the Interstellar Medium" Astronomy and Astrophysics Vol. 645 (2020) ISSN: 0004-6361; 1432-0746
Available at: http://works.bepress.com/richard_dawes/138/