Jitter radiation model of the Crab gamma ray flares

TL;DR

This paper proposes a jitter radiation model to explain the Crab nebula gamma-ray flares, suggesting that turbulent magnetic fields enable higher photon energies than traditional synchrotron limits, with specific observational predictions.

Contribution

It introduces a jitter radiation mechanism involving small-scale magnetic turbulence to explain high-energy gamma-ray flares in the Crab nebula, surpassing synchrotron energy constraints.

Findings

Jitter radiation can produce photons with energies exceeding synchrotron limits.

The model predicts lower polarization during flares.

No TeV-PeV counterparts are expected during flares.

Abstract

The gamma ray flares of the Crab nebula detected by Fermi and AGILE satellites challenge our understanding of physics of pulsars and their nebulae. The central problem is that the peak energy of the flares exceeds the maximum energy E_{\mathrm{c}} determined by synchrotron radiation loss. However, when there exist turbulent magnetic fields with scales \lambda_{\mathrm{B}} smaller than 2\pi mc^2/eB, jitter radiation can emit photons with energy higher than E_{\mathrm{c}}. The scale required for the Crab flares is about two orders of magnitude less than the wavelength of the striped wind. We discuss the model in which the flares are triggered by plunging of the high density blobs into the termination shock. The observed hard spectral shape may be explained by jitter mechanism. We make three observational predictions: firstly the polarization degree will become lower in flares, secondly, no counterpart will be seen in TeV-PeV range, and thirdly the flare spectrum will not be harder than \nu F_\nu \propto \nu^1.