On the rotation measure and turbulent structure of the Vela supernova remnant

We derive both the correlation function and its associated power spectrum for the rotation measure across the Vela supernova remnant. We find that: (i) the contours of constant correlation and those of the associated power spectrum are roughly elliptical, the ellipticity being independent of contour level: (ii) the contours of constant correlation systematically rotate as the level of correlation decreases, whilst the constant power contours remain fixed as the power decreases: (iii) a scale length approx. equal to 15 can be identified in both the correlation function and power spectrum. Theoretical estimates of scale lengths for both the Rayleigh-Taylor instability and the thermal instability are similar to the observed scale length, suggesting that the turbulence is evolving with the supernova remnant. (orig.)