The Spectrum of Electromagnetic Jets from Kerr Black Holes and Naked Singularities in the Teukolsky Perturbation Theory

TL;DR

This paper develops a theoretical framework using the Teukolsky equation to distinguish Kerr black holes from naked singularities by analyzing electromagnetic jet spectra, revealing stable jet characteristics across both objects.

Contribution

It introduces a novel method to identify Kerr black holes or naked singularities via their electromagnetic jet spectra based on boundary conditions in the Teukolsky equation.

Findings

Spectra differ qualitatively between Kerr black holes and naked singularities.

Primary electromagnetic jets are shown to be linearly stable in both cases.

Jet spectra depend on the rotation parameter of the Kerr metric.

Abstract

We give a new theoretical basis for examination of the presence of the Kerr black hole (KBH) or the Kerr naked singularity (KNS) in the central engine of different astrophysical objects around which astrophysical jets are typically formed: X-ray binary systems, gamma ray bursts (GRBs), active galactic nuclei (AGN), etc. Our method is based on the study of the exact solutions of the Teukolsky master equation for electromagnetic perturbations of the Kerr metric. By imposing original boundary conditions on the solutions so that they describe a collimated electromagnetic outflow, we obtain the spectra of possible {\em primary jets} of radiation, introduced here for the first time. The theoretical spectra of primary electromagnetic jets are calculated numerically. Our main result is a detailed description of the qualitative change of the behavior of primary electromagnetic jet frequencies under the transition from the KBH to the KNS, considered here as a bifurcation of the Kerr metric. We show that quite surprisingly the novel spectra describe linearly stable primary electromagnetic jets from both the KBH and the KNS. Numerical investigation of the dependence of these primary jet spectra on the rotation of the Kerr metric is presented and discussed.