Variabilities of Gamma-ray Bursts from Black Hole Hyper-accretion Disks

TL;DR

This paper investigates the variability of gamma-ray burst jet power using a propagating fluctuations model, suggesting a common mechanism with variabilities observed in black hole binaries and active galactic nuclei.

Contribution

It extends the propagating fluctuations model to gamma-ray bursts, demonstrating its potential to explain GRB prompt emission variability.

Findings

Jet power variability in GRBs resembles observed light curves.

Mechanism for X-ray variabilities in BHBs and AGNs may also drive GRB variabilities.

Model reproduces erratic spike profiles similar to observations.

Abstract

The emission from black hole binaries (BHBs) and active galactic nuclei (AGNs) displays significant aperiodic variabilities. The most promising explanation for these variabilities is the propagating fluctuations in the accretion flow. It is natural to expect that the mechanism driving variabilities in BHBs and AGNs may operate in a black hole hyper-accretion disk, which is believed to power gamma-ray bursts (GRBs). We study the variabilities of jet power in GRBs based on the model of propagating fluctuations. It is found that the variabilities of jet power and the temporal profile of erratic spikes in this scenario are similar to those in observed light curves of prompt gamma-ray emission of GRBs. Our results show that the mechanism driving X-ray variabilities in BHBs and AGNs may operate in the central engine to drive the variabilities of GRBs.