2025/06/02 by Kyohei Kawaguchi, Kawaguchi, Kyohei, Sho Fujibayashi +3
Physics and Astronomy · #Accretion (finance) #Annihilation #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Gamma-ray burst #General Relativity and Quantum Cosmology (gr-qc) #High Energy Astrophysical Phenomena (astro-ph.HE) #Kinetic energy #Neutrino #Neutrino Physics Research #Outflow #Particle physics theoretical and experimental studies #Scaling #Torus
paper · pdf · doi:10.48550/arxiv.2506.01679
openalex publication_date 2025/06/02 · openalex created_date 2025/10/09 · openalex updated_date 2026/08/05
We perform axisymmetric general relativistic radiation-viscous hydrodynamics simulations of black hole (BH)-torus systems with full Boltzmann Monte-Carlo neutrino transport to investigate the role of neutrino-antineutrino pair annihilation in launching relativistic outflows. Our models span a wide range of BH spins, torus masses, and viscosity parameters. We find that the pair annihilation leads to the formation of relativistic fireballs in most cases, except for those with low black-hole spin and high viscosity. The isotropic-equivalent energies of these outflows reach \lesssim 1051 \rm erg with durations \lesssim 0.2 \rm s. While this is insufficient to explain the brightest short gamma-ray bursts (sGRBs), our results suggest that the pair annihilation may account for some low-luminosity sGRBs and GRB precursors. We also provide updated scaling relations for the pair annihilation energy deposition rate as a function of accretion rate, and discuss the sensitivity of outflow properties to numerical resolution and floor density.