BEXCO - Room B(103/104/105)
[CRI018] Particle acceleration model for the broadband baseline spectrum of the Crab nebula
We develop a simple one-zone model of the steady-state Crab nebula spectrum encompassing both the radio/soft X-ray and the GeV/multi-TeV observations. We determine analytically the photon differential energy spectrum as originated by an electron distribution evolved from a log-parabola injection spectrum. We find an impressive agreement with the synchrotron region observations whereas synchrotron self-Compton accommodates the previously unsolved origin of the broad 200 GeV peak that matches the Fermi/LAT data beyond 1 GeV with the MAGIC data. We determine the parameters of the log-parabola electron distribution, ruling out a simple power-law. The scale of the acceleration region is found to be about 3.8e-4 pc. The resulting photon differential spectrum provides a natural interpretation of the deviation from power-law customarily fit with empirical broken power-laws. Our model can be applied to the radio-to-multi-TeV spectrum of a variety of astrophysical sources of relativistic flows as well as to fast interplanetary shocks.