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Main Author: Lei, Wei-Hua
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2603.15028
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author Lei, Wei-Hua
author_facet Lei, Wei-Hua
contents A hyperaccreting stellar-mass black hole (BH) has been proposed as the candidate central engine of gamma-ray bursts (GRBs). Comparing the predictions from the central engine models with the temporal behavior of GRBs is of great interest. In this paper, using the open-source GRMHD HARM-COOL code, we evolve several 2D magnetized hyperaccreting BH models with realistic equation of state in a fixed curved space-time background. We extend the code to include the calculation of neutrino annihilation power. We then study the time evolution of BH central engine parameters, i.e., the neutrino annihilation power, the Blandford-Znajke (BZ) power, and the initial magnetization $σ_0$. We find that the neutrino power is generally consistent with previous analytical results. Usually, the neutrino annihilation process tends to launch a thermal ``fireball'', while the BZ jet is Poynting-flux-dominated. Our results, especially the evolution characteristics of $σ_0$ may help to understand the complex GRB spectral behavior.
format Preprint
id arxiv_https___arxiv_org_abs_2603_15028
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Investigating the Temporal Evolution of Gamma-Ray Burst Central Engine Parameters Based on Numerical Simulations
Lei, Wei-Hua
High Energy Astrophysical Phenomena
A hyperaccreting stellar-mass black hole (BH) has been proposed as the candidate central engine of gamma-ray bursts (GRBs). Comparing the predictions from the central engine models with the temporal behavior of GRBs is of great interest. In this paper, using the open-source GRMHD HARM-COOL code, we evolve several 2D magnetized hyperaccreting BH models with realistic equation of state in a fixed curved space-time background. We extend the code to include the calculation of neutrino annihilation power. We then study the time evolution of BH central engine parameters, i.e., the neutrino annihilation power, the Blandford-Znajke (BZ) power, and the initial magnetization $σ_0$. We find that the neutrino power is generally consistent with previous analytical results. Usually, the neutrino annihilation process tends to launch a thermal ``fireball'', while the BZ jet is Poynting-flux-dominated. Our results, especially the evolution characteristics of $σ_0$ may help to understand the complex GRB spectral behavior.
title Investigating the Temporal Evolution of Gamma-Ray Burst Central Engine Parameters Based on Numerical Simulations
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2603.15028