Hydrodynamical simulations of a compact source scenario for G2

Abstract

AbstractThe origin of the dense gas cloud “G2” discovered in the Galactic center (Gillessen et al. 2012) is still a debated puzzle. G2 might be a diffuse cloud or the result of an outflow from an invisible star embedded in it. We present here detailed simulations of the evolution of winds on G2's orbit. We find that the hydrodynamic interaction with the hot atmosphere present in the Galactic center and the extreme gravitational field of the supermassive black hole must be taken into account when modeling such a source scenario. We also find that in this scenario most of the Brγ luminosity is expected to come from the highly filamentary densest shocked wind material. G2's observational properties can be used to constrain the properties of the outflow and our best model has a mass outflow rate of Ṁw=8.8 × 10−8 M⊙ yr−1 and a wind velocity of vw = 50 km s−1. These values are compatible with those of a young TTauri star wind, as already suggested by Scoville & Burkert (2013).