A two-component jet model based on the Blandford-Znajek and Blandford-Payne processes

TL;DR

This paper introduces a two-component jet model driven by Blandford-Znajek and Blandford-Payne processes, explaining observations of GRBs and AGNs and constraining physical parameters through Lorentz factor fitting.

Contribution

It presents a novel two-component jet model combining BZ and BP processes, providing a unified explanation for jet structures in GRBs and AGNs.

Findings

The model fits Lorentz factors of specific GRBs and AGNs.

The jet structure can be naturally interpreted as spine/sheath.

Physical parameters related to accretion and outflow are constrained.

Abstract

We propose a two-component jet model consistent with the observations of several gamma ray bursts (GRBs) and active galactic nuclei (AGNs). The jet consists of inner and outer components, and they are supposed to be driven by the Blandford-Znajek (BZ) and Blandford-Payne (BP) processes, respectively. The baryons in the BP jet is accelerated centrifugally via the magnetic field anchored in the accretion disk. The BZ jet is assumed to be entrained a fraction of accreting matter leaving the inner edge of the accretion disk, and the baryons are accelerated in the conversion from electromagnetic energy to the kinetic energy. By fitting the Lorentz factors of some GRBs (GRB 030329, GRB 051221A, GRB 080413B) and AGNs (Cen A, Mkn 501 and Mkn 421) with this model, we constrain the physical parameters related to the accretion and outflow of these two kind of objects. We conclude that the spine/sheath structure of the jet from these sources can be interpreted naturally by the BZ and BP processes.