Black Hole to Photosphere: 3D GRMHD Simulations of Collapsars Reveal Wobbling and Hybrid Composition Jets

Abstract Long-duration ? -ray bursts (GRBs) accompany the collapse of massive stars and carry information about central engine. However, no 3D models have been able to follow these jets from their birth via black hole (BH) photosphere. We present first such general-relativity magnetohydrodynamic simulations, which span over six orders magnitude in space time. The collapsing stellar envelope forms an accretion disk, drags inwardly magnetic flux that accumulates around BH, becomes dynamically important, launches bipolar jets. reach photosphere at ?10 12 cm with opening angle ? j ? 6° a Lorentz factor ? ? 30, unbinding ?90% star. find (i) disk–jet system spontaneously develops misalignment relative BH rotational axis. As result, jet wobbles t 12°, can naturally explain quiescent times GRB lightcurves. effective for detection + suggests intrinsic rate is lower by order than standard estimates. This successful GRBs are rarer currently thought emerge only ?0.1% supernovae Ib/c, implying either not launched or choked inside most supernova Ib/c progenitors. (ii) energy decreases due mixing star, resulting hybrid composition thermal components photosphere, where ?10% gas maintains magnetization ? ? 0.1. indicates both photospheric component reconnection may play role prompt emission.