RM values from the catalog of TSS09 mapped on the extinction map of Orion. OMC-A is the complex to the south and OMC-B is the complex to the north. Blue (red) circles indicate positive (negative) RM values. The size of the circles is proportional to the magnitude of the RM. The gray grid provides galactic coordinates, whereas the black grid provides equatorial coordinates. Color image shows the extinction map (A_V) in units of magnitudes of visual extinction provided by KBHP09.