| Author(s) and Co-Author(s) with Affiliation: Krishna Kumar(University of Leeds, Woodhouse, Leeds LS2 9JT,United KingdomUniversity of Leeds, Woodhouse, Leeds LS2 9JT,United Kingdom), Rushikesh Sonawane(Center for High Performance Computing, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram), Ore Gottlieb(Center for Computational Astrophysics, Flatiron Institute, New York, NY 10010, United States), Shabnam Iyyani(School of Physics, IISER Thiruvananthapuram, Kerala, 695551, India) |
| Abstract: Long gamma-ray bursts (LGRBs) are believed to originate from the rapid core collapse of massive Wolf–Rayet stars, leading to the formation of a spinning black hole. The rotation of the black hole powers a relativistic jet that drills through the stellar envelope, and the prompt gamma-ray emission observed in LGRBs arises once this jet successfully emerges. In this work, we perform an extensive suite of two-dimensional axisymmetric relativistic hydrodynamic (RHD) simulations using the PLUTO code to model semi-self-consistent, accretion-powered LGRB jets launched by Kerr black holes of mass 5 solar masses. We investigate jet breakout conditions in Wolf–Rayet progenitors of 10 and 25 solar masses with corresponding radii of 4×10^10 cm and 10^11 cm, respectively. The injected jet power naturally varies with black hole spin. Our results show that black holes with a spin parameter a>0.001 successfully launch jets, whereas those with a ≤ 0.001 produce choked jets. For successful jets, the breakout timescale exhibits clear correlations with both jet luminosity and black hole spin, revealing three distinct dynamical regimes: a Newtonian regime at low spin (a≤0.03), a relativistic regime at high spin (a ≥ 0.2), and an intermediate transition regime. These results highlight black hole spin as a critical parameter governing jet formation and breakout in collapsar-driven LGRBs. |
