Simulating the effect of the Sgr A* accretion flow on the appearance of G2 after pericentre

Abstract

We study the dynamical interaction of the G2 cloud with the accretion flow around Sgr A* by means of 3D, hydrodynamic simulations.We show the effects of the rotating accretion flow on the evolution of G2 by projecting the cloud density on to the plane of the sky, and extracting position-velocity diagrams.We study a number of possible orientations of the cloud orbit with respect to the disc.We find that once the centre of mass of the cloud has crossed the pericentre, the differences between models become significant. Models with the cloud counterrotating with respect to the disc are expected to reach higher blueshifted line-of-sight velocities. The spatial extent of the emission depends strongly on the cloud-to-disc inclination angle. Future imaging and spectroscopy of G2 emission will shed light both on the structure of the Sgr A* disc and on the properties of the cloud. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.