of the magnetic field. In region C, the orientations of the $\overrightarrow{E}$-vectors do not appear to show a coherent pattern, making their interpretation more difficult. Finally, we note that the peak fractional polarization decreases from the outer to the central regions. Its value ranges from 9.7% and 16.4% in the (outer) regions A and C respectively down to 2.2% in the (inner) region B.

           Array                 CARMA                 SMA                 ALMA
  ----------------------- -------------------- -------------------- -------------------
        $\nu$ (GHz)               230                  345                  345
   Beam Size ($\arcsec$)     4.6$\times$2.4       2.5$\times$1.9      0.5$\times$0.4
     $\Theta{\arcsec}$      15.3$\times$8.8       7.3$\times$5.7      8.0$\times$3.0
         $D_{pc}$           0.15$\times$0.08     0.07$\times$0.05    0.08$\times$0.03
         $D_{AU}$          30600$\times$17600   14600$\times$11400   16000$\times$6000

  : \[tabcomp\] Summary of the available dust polarimetric observations.

$\Theta{\arcsec}$, $D_{pc}$ and $D_{AU}$ indicate the angular extent and approximate size of the thermal emission in arcsec, parsec and AU respectively, assuming a distance of 1639 pc for the nebula. The two last values are corrected from the 35inclination angle of the source.

![image](FullStokesI2-eps-converted-to.pdf){height="10cm"}

![image](CompB3-eps-converted-to.pdf){height="9cm"}

![ALMA map of the magnetic field distribution of vectors generated with a zoom on the region ”C”. The beam size is shown on the left lower corner. []{data-label="ZoomC"}](ZoomC-eps-converted-to.pdf){height="8.5cm"}

Multi-scale dust polarization analysis {#comp}
======================================

It is generally assumed that the polarization of ISM thermal dust emission observed at long (e.g. submillimeter 