Relativistic global solutions of neutrino-dominated accretion flows with magnetic coupling

TL;DR

This paper presents relativistic, global solutions for neutrino-dominated accretion flows around Kerr black holes, incorporating magnetic coupling effects, and explores their impact on structure, neutrino luminosity, and nucleosynthesis.

Contribution

It introduces one-dimensional global solutions of NDAFs with magnetic coupling, including relativistic effects and detailed physics, highlighting the influence of magnetic fields on accretion properties.

Findings

Magnetic coupling significantly alters NDAF structure and thermal properties.

Neutrino luminosities and annihilation rates increase with magnetic coupling.

Heavy nuclei synthesis regions extend further out due to magnetic effects.

Abstract

A Kerr black hole (BH) surrounded by a neutrino-dominated accretion flow (NDAF) is one of plausible candidates of the central engine in gamma-ray bursts. The accretion material might inherit and restructure strong magnetic fields from the compact object mergers or massive collapsars. The magnetic coupling (MC) process between a rapid rotating BH and an accretion disc is one of possible magnetic configurations that transfers the energy and angular momentum from the BH to the disc. In this paper, we investigate one-dimensional global solutions of NDAFs with MC (MCNDAFs), taking into account general relativistic effects, detailed neutrino physics, different MC geometries, and reasonable nucleosynthesis processes. Six cases with different accretion rates and power-law indices of magnetic fields are presented and compared with NDAFs without MC. Our results indict that the MC process can prominently impact the structure, thermal properties, and microphysics of MCNDAFs, increase luminosities of neutrinos and their annihilations, result in the changing of radial distributions of nucleons, and push the region of heavy nuclei synthesis to a larger radius than counterparts in NDAFs.