Theoretical study of ArH+ dissociative recombination and electron-impact vibrational excitation

Abstract

Cross sections are presented for dissociative recombination and electron-impact vibrational excitation of the ArH+ molecular ion at electron energies appropriate for the interstellar environment. The R-matrix method is employed to determine the molecular structure data, i.e. the position and width of the resonance states. The cross sections and the corresponding Maxwellian rate coefficients are computed using a method based on the Multichannel Quantum Defect Theory. The main result of the paper is the very low dissociative recombination rate found at temperatures below 1000K. This is in agreement with the previous upper limit measurement in merged beams and offers a realistic explanation to the presence of ArH+ in exotic interstellar conditions.

arXiv comment6 pages; 7 figures

References in corpus (8)

• Detection of a Noble Gas Molecular Ion, {36}ArH^+, in the Crab Nebula
• Ubiquitous argonium (ArH${}^{+}$) in the diffuse interstellar medium -- a molecular tracer of almost purely atomic gas
• Detection of extragalactic argonium, ArH${}^{+}$, toward PKS~1830$-$211
• The chemistry of interstellar argonium and other probes of the molecular fraction in diffuse clouds
• Photodissociation of interstellar ArH+
• Electron-impact excitation of diatomic hydride cations I: HeH${}^{+}$, CH${}^{+}$, ArH${}^{+}$
• Rotational transitions induced by collisions of HD${}^{+}$ ions with low energy electrons
• Modelling the ArH${}^{+}$ emission from the Crab Nebula

Cited by in corpus (4)

• Low-energy electron impact dissociative recombination and vibrational transitions of N${}_2^{+}$
• Exploring the Possibility of Identifying Hydride and Hydroxyl Cations of Noble Gas Species in the Crab Nebula Filament
• Electron-impact cross sections for dissociation processes of vibrationally excited CH radical
• ArH+ and H2O+ absorption towards luminous galaxies