3D AMR hydrosimulations of a compact-source scenario for the Galactic Centre cloud G2

The nature of the gaseous and dusty cloud G2 in the Galactic Centre is still under debate. We present three-dimensional hydrodynamical adaptive mesh refinement simulations of G2, modelled as an outflowfrom a 'compact source'moving on the observed orbit. The construction of mock position-velocity (PV) diagrams enables a direct comparison with observations and allows us to conclude that the observational properties of the gaseous component of G2 could be matched by amassive (M˙w = 5 × 10-7M˙yr-1) and slow(50 kms-1) outflow, as observed for T Tauri stars. In order for this to be true, only the material at larger (>100AU) distances from the source must be actually emitting; otherwise G2 would appear too compact compared to the observed PV diagrams. On the other hand, the presence of a central dusty source might be able to explain the compactness of G2's dust component. In the present scenario, 5-10 years after pericentre the compact source should decouple from the previously ejected material, due to the hydrodynamic interaction of the latterwith the surrounding hot and dense atmosphere. In this case, a new outflow should form, ahead of the previous one, which would be the smoking gun evidence for an outflow scenario.