Pulsar Wind Nebulae (PWNe) constitute an ideal astrophysical environment to
test our current understanding of relativistic plasma processes. It is well
known that magnetic fields play a crucial role in their dynamics and emission
properties. At present, one of the main issues concerns the level of magnetic
turbulence present in these systems, which in the absence of space resolved
X-ray polarization measures cannot be directly constrained. In this work we
investigate, for the first time using simulated synchrotron maps, the effect of
a small scale fluctuating component of the magnetic field on the emission
properties in X-ray. We illustrate how to include the effects of a turbulent
component in standard emission models for PWNe, and which consequences are
expected in terms of net emissivity and depolarization, showing that the X-ray
surface brightness maps can provide already some rough constraints. We then
apply our analysis to the Crab and Vela nebulae and, by comparing our model
with Chandra and Vela data, we found that the typical energies in the turbulent
component of the magnetic field are about 1.5 to 3 times the one in the ordered
field.Comment: 9 pages, 8 figures, accepted for publication in MNRA
