  In order to improve our understanding of the kinetics of the cometary coma,
theoretical studies of the major reactive collisions in these environments are
needed. Deep in the collisional coma, inelastic collisions between thermal
electrons and molecular ions result in recombination and vibrational
excitation, the rates of these processes being particularly elevated due to the
high charged particle densities in the inner region. This work addresses the
dissociative recombination, vibrational excitation, and vibrational
de-excitation of electrons with CO$^+$ molecular cations. The aim of this study
is to understand the importance of these reactive collisions in producing
carbon and oxygen atoms in cometary activity. The cross-section calculations
were based on Multichannel Quantum Defect Theory. The molecular data sets, used
here to take into account the nuclear dynamics, were based on ab initio
R-matrix approach. The cross sections for the dissociative recombination,
vibrational excitation, and vibrational de-excitation processes, for the six
lowest vibrational levels of CO$^+$ - relevant for the electronic temperatures
observed in comets - are computed, as well as their corresponding Maxwell rate
coefficients. Moreover, final state distributions for different dissociation
pathways are presented. Among all reactive collisions taking place between
low-energy electrons and CO$^+$, the dissociative recombination is the most
important process at electronic temperatures characterizing the comets. We have
shown that this process can be a major source of O($^3$P), O($^1$D), O($^1$S),
C($^3$P) and C($^1$D) produced in the cometary coma at small cometocentric
distances.
