Extreme luminosities in ejecta produced by intermittent outflows around rotating black holes

TL;DR

This paper investigates how intermittent outflows from rotating black holes produce extreme relativistic ejecta, leading to gamma-ray bursts, through numerical simulations of magnetohydrodynamics and flux interactions.

Contribution

It introduces a new model linking magnetic flux advection and duty cycle to ejecta morphology and explosion mechanisms in black hole systems.

Findings

Enhanced interactions at high accretion rates boost ejecta energy.

Relativistic ejecta morphology and propagation are demonstrated via simulations.

Complex ejecta geometries lead to broadband high-energy emission pathways.

Abstract

Extreme sources in the Transient Universe show evidence of relativistic outflows from intermittent inner engines, such as cosmological gamma-ray bursts. They probably derive from rotating back holes interacting with surrounding matter. We show that these interactions are enhanced inversely proportional to the duty cycle in advection of magnetic flux, as may apply at high accretion rates. We demonstrate the morphology and ballistic propagation of relativistic ejecta from burst outflows by numerical simulations in relativistic magnetohydrodynamics. Applied to stellar mass black holes in core-collapse of massive stars, it provides a robust explosion mechanism as a function of total energy output. At breakout, these ejecta may produce a low-luminosity GRB. A long GRB may ensue from an additional ultra-relativistic baryon-poor inner jet from a sufficiently long-lived intermittent inner engine. The simulations demonstrate a complex geometry in mergers of successive ejecta, whose mixing and shocks provide a pathway to broadband high energy emission from magnetic reconnection and shocks.