Intercambio de carga entre iones multicargados y helio neutro

En numerosos plasmas astrofísicos y de laboratorio -notablemente el medio interestelar, las nebulosas planetarias, las galaxias de Seyfert, los plasmas Tokamak, etc.- la abundancia de los iones multicargados está en gran parte controlada por las reacciones de intercambio de carga que éstos efectúan con el gas neutro (McCarroll y Valiron 1978, Péquignot y colaboradores 1978, Péquignot 1980, Miller y colaboradores 1974).Asociación Argentina de Astronomí

Tasas de reacción para colisiones de intercambio de carga entre iones e hidrógeno excitado

We are presenting theoretical reaction rates for charge exchange low energy collisions between HII and HeII projectiles colliding with meta-estable (2s) HI targets. The calculations have been performed for temperatures ranging from 10³ to 10⁷ K. A Maxwell function has been assumed to describe the energy distribution of the relative movement. The results are of interest for the determination of the ionization equilibrium of the involved atomic species under astrophysical conditions.Asociación Argentina de Astronomí

Excitation of OIII by charge transfer of OIV with HI

Calculations re presented of reaction rates for the charge transfer reaction between OIV ions and atomic hydrogen that populate the ¹P,²D,³P, 3ˢ states of the (2pep) configuration and the ¹P⁰,³P⁰ states of the (2p3s) configuration of OIII. The temperatures considered range between 1000 and 50000 K. By approximating the system by a quasi-molecule, the theoretical study of the collision was made with the method of Grice and Herschbach (1974, Mol. Phys. 27, 159) where the orbitals were generated by the model potential method. Our results are consistent with the astrophysical observations of the 5592 Å emission line of OIII in planetary nebulae and are also compared with the computed avlues of Dalgarno, Heil and Butler (1981, Astrophys. J. 245, 793) obtained with the usual techniques of quantum chemistry.Asociación Argentina de Astronomí