3D Simulations of the Local Bubble

We have performed high resolution 3D simulations of the Local Bub- ble (with 1.25 pc nest resolution) in a realistic background ISM, jointly with the dynamical evolution of the neighbouring Loop I superbubble. We can reproduce (i) the size of the bubbles (in contrast to similarity solutions), (ii) the interaction shell with Loop I, discovered with ROSAT, (iii) predict the merging of the two bubbles in about 3 Myr, when the interaction shell starts to fragment, and, (iv) the generation of blobs like the Local Cloud as a consequence of a dynamical instability. The Local Bubble (LB) is a cavity, elongated towards the Galactic North Pole, with an average extension of about 100 pc, copiously ra- diating in soft X-rays. There exist a number of discrepancies between observations and modelling that have all been outlined in a recent panel discussion (Breitschwerdt & Cox 2004). Most models proceed from a multi-supernova origin of the LB (cf. Berghofer & Breitschwerdt 2002 for possible supernova (SN) progenitors), in which the LB is the result of successive SN explosions, although part of the soft X-ray emission could be of heliospheric origin, generated by charge exchange reactions between solar wind ions and heliospheric plasma.