Giant explosion at the Galactic center and huge shocked shells in the halo

We simulate the propagation of a shock front through the galactic halo induced by an explosion and/or a starburst at the galactic center. A huge dumbbell (Ω)-shaped shock front produced by an explosion of energy 3× 10⁵⁶ ergs about fifteen million years ago can mimic the radio and X-ray North Polar Spur as well the southern large X-ray spur. The post-shock high-temperature gas in the corona will explain the observed X-ray bulge around the galactic center. Key workds Galaxy: center -- Galaxy: halo -- Radio continuum: general -- Shock wave -- X-rays: general