Modeling the broadest spectral band of the Crab nebula and constraining the ions acceleration efficiency

Abstract

Although it is widely accepted that the electromagnetic spectrum from radio to very-high-energy $\gamma$-rays of pulsar wind nebulae (PWNe) originates from leptons, there is still an open question that protons (or more generally, ions) may exist in pulsar wind and are further accelerated in PWN. The broadband spectrum of the prototype PWN Crab, extended recently by the detection of the Tibet AS$\gamma$ and HAWC experiments above 100 TeV, may be helpful in constraining the acceleration efficiency of ions. Here, we model the broadest energy spectrum of Crab and find that the broadband spectrum can be explained by the one-zone leptonic model in which the electrons/positrons produce the emission from radio to soft $\gamma$-rays via the synchrotron process, and simultaneously generate the GeV-TeV $\gamma$-rays through inverse Compton scattering including the synchrotron self-Compton process. In the framework of this leptonic model, the fraction of energy converted into the energetic protons is constrained to be below $0.5(n_{\mathrm{t}}/10{\mathrm{cm}}^{-3}{)}^{-1}$ per cent, where $n_{\mathrm{t}}$ is the target gas density in the Crab. However, this fraction can be up to $7(n_{\mathrm{t}}/10{\mathrm{cm}}^{-3}{)}^{-1}$ per cent if only the $\gamma$-rays are used.

7 pages, 6 figures, accepted for publication in MNRAS

References in corpus (13)

• Observations of the Crab Nebula with H.E.S.S
• Electrodynamics of axisymmetric pulsar magnetosphere with electron-positron discharge: a numerical experiment
• Spitzer Space Telescope Infrared Imaging and Spectroscopy of the Crab Nebula
• The dust and gas content of the Crab Nebula
• Non-thermal emission from relativistic MHD simulations of PWNe: from synchrotron to inverse Compton
• Far-infrared and sub-mm observations of the Crab nebula
• MAGIC very large zenith angle observations of the Crab Nebula up to 100 TeV
• Proton acceleration in pulsar magnetospheres
• Crab Nebula: five-year observation with ARGO-YBJ
• IceCube Search for High-Energy Neutrino Emission from TeV Pulsar Wind Nebulae
• A possible approach to three-dimensional cosmic-ray propagation in the Galaxy IV. Electrons and electron-induced gamma-rays
• Turbulent model of Crab nebula radiation
• Multiwavelength Investigation of Pulsar Wind Nebula DA 495 with HAWC, VERITAS, and NuSTAR

Cited by in corpus (11)

• Peta-electron volt gamma-ray emission from the Crab Nebula
• PeV emission of the Crab Nebula: constraints on the proton content in pulsar wind and implications
• Multi-band Emission up to PeV Energy from the Crab Nebula in a Spatially Dependent Lepto-hadronic Model
• Ultrahigh-energy Gamma-Ray Radiation from the Crab Pulsar Wind Nebula
• Ultra-High-Energy Gamma-Ray Astronomy
• Investigating the energy distribution of the high-energy particles in the Crab nebula
• Hadronic emission from the environment of the Crab Pulsar Wind Nebula by re-accelerated particles
• A Possible Gamma-Ray Enhancement Event in Tycho's Supernova Remnant
• The Potential for Hadronic Particle Acceleration in Galactic Pulsar Wind Nebulae
• Hadronic Re-Acceleration at the Crab Pulsar Wind Termination Shock as a Source of PeV Gamma-Rays
• Energy-dependent extension of the Crab Nebula as a diagnostic of ultrahigh-energy hadronic emission