On the spectrum of the pulsed gamma-ray emission from 10MeV to 400GeV of the Crab pulsar

TL;DR

This paper presents a self-consistent theory explaining the Crab pulsar's pulsed gamma-ray emission from 10MeV to 400GeV, linking observed spectra to synchrotron radiation from ultra-relativistic electrons near the light cylinder.

Contribution

It introduces a novel model connecting high-energy emission to cyclotron instability and Landau damping, explaining the spectral shape and particle energies in the pulsar magnetosphere.

Findings

Spectral indexes of 2 and 3.8 fit observations

High-energy electrons reach Lorentz factors up to 10^9

Simultaneous generation of radio and gamma-ray emission

Abstract

In the present paper a self-consistent theory, interpreting the VERITAS observations of the very high energy pulsed emission from the Crab pulsar is considered. The photon spectrum between 10MeV and 400GeV can be described by two power-law functions with the spectral indexes equal to 2 and 3.8. The source of the pulsed emission above 10MeV is assumed to be the synchrotron radiation, which is generated near the light cylinder during the quasi-linear stage of the cyclotron instability. The emitting particles are the primary beam electrons with the Lorentz factors up to $10^{9}$. Such high energies by beam particles is supposed to be reached due to Landau damping of the centrifugally induced Langmuir waves. This mechanism provides simultaneous generation of low (radio) and high energy (10MeV-400GeV) emission on the light cylinder scales, in one location of the pulsar magnetosphere.