3D simulations of RS Ophiuchi: from accretion to nova blast

Abstract

Context. The binary star system RS Ophiuchi is a recurrent nova, with outbursts occurring about every 22 years. It consists of a red giant star (RG) and a wind accreting white dwarf close to the Chandrasekhar limit. This system is considered a prime candidate for evolving into an SNIa. For its most recent outbursts in 1985 and 2006, exquisite multiwavelength observational data are available. Aims. Deeper physical insight is needed regarding the inter-outburst accretion phase and the dynamical effects of the subsequent nova explosion in order to improve the interpretation of the observed data and to shed light on whether the system is an SNIa progenitor. Methods. We present a 3D hydrodynamic simulation of the quiescent accretion with the subsequent explosive phase. Results. The computed circumstellar mass distribution in the quiescent phase is highly structured with a mass enhancement in the orbital plane of about a factor of 2 as compared to the poleward directions. The simulated nova remnant evolves aspherically, propagating faster toward the poles. The shock velocities derived from the simulations agree with those derived from observations. For vRG = 20 km s −1 and for nearly isothermal flows, we find that 10% of the mass lost by the RG is transfered to the WD. For an RG mass