Energy and Geometry of Jet-driven Explosions in the Local Universe

We propose an in-depth study of a nearby long gamma-ray burst (GRB, z < 0.4) with XMM. Our synergistic multi-wavelength effort (radio, optical, Swift/XRT and proposed XMM) is de- signed to extract the true energy and geometry of these explosions, and to reveal the activity of their central engines. This effort allows us to: (i) investigate whether sub-energetic GRBs share the same explosion mechanisms and central engines as ordinary GRBs; (ii) investigate what essential physical property enables only a small fraction of supernovae to harbor a relativistic GRB outflow; (iii) understand if “jet-driven” explosions are common in all supernovae. These objectives are only possible by expanding the current small sample of nearby GRBs and by drawing comparisons with cosmological GRBs and ordinary SNe.