Three-dimensional simulations of the interaction between the nova ejecta, the accretion disk, and the companion star

Context. Classical novae are thermonuclear explosions hosted by accreting white dwarfs in stellar binary systems. Material piles up on top of the white dwarf star under mildly degenerate conditions, driving a thermonuclear runaway. The energy released by the suite of nuclear processes operating at the envelope (mostly proton-capture reactions and beta-decays) heats the material up to peak temperatures ranging from 100 to 400 MK. In these events, about 10-3 - 10-7 Msun, enriched in CNO and, sometimes, other intermediate-mass elements (e.g., Ne, Na, Mg, Al), are ejected into the interstellar medium. Aims. To date, most of the efforts undertaken in the modeling of classical nova outbursts have focused on the early stages of the explosion and ejection, ignoring the interaction of the ejecta, first with the accretion disk orbiting the white dwarf, and ultimately with the secondary star. Methods. A suite of three-dimensional, SPH simulations of the interaction between the nova ejecta, the accretion disk, and the stellar companion have been performed to fill this gap, aimed at testing the influence of the different parameters (i.e., mass and velocity of the ejecta, mass and geometry of the accretion disk) on the dynamical and chemical properties of the system. Results. We discuss the conditions that lead to the disruption of the accretion disk and to mass loss from the binary system. In addition, we discuss the likelihood of chemical contamination of the stellar secondary induced by the impact with the nova ejecta and its potential effect on the next nova cycle.