The Leo Triplet member NGC 3627
A comparison of the total power (colours) and polarization (contours) images of NGC 3627 made with the VLA at 3.6 cm. Note the polarized arm crossing the total power one in the SW part of the disk. Instrument: VLA at 3.6 cm.
The above effect is also seen in the geometry of polarization B-vectors. Note that the apparent B-vectors follow well the NW and western part of the spiral structure while crossing the SE spiral arm despite a strong compression, as indicated by a heavy dust lane accompanied by a chain of star-forming regions. Instrument: VLA at 3.6 cm.
The "phase diagram" of NGC 3627: the X-axis is an azimuthal angle in the disk, measured CCW from the northern tip of the major axis, while the Y-axis is a natural logarithm of the galactocentric distance. Both quantities are corrected to the face-on position of the galaxy. The colour scale depicts the distribution of the polarized intensity at 3.6 cm, while the bars show the orientation of polarization B-vectors. Made out of the data gathered by VLA at 3.6 cm. Details are described in: Soida et al. 2001.