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