Contours of SCUBA 850 μm dust emission (Orion KL; Di Francesco et al. 2008) overlaid on the 6 cm VLA continuum image of the M 42 H II region. The red cross is IRc2 of Orion KL (RA(J2000) = 05:35:14.55, Dec(J2000) = −05:22:31.0). The red pentagram denotes θ¹ Ori C (RA(J2000) = 5:35:16.47, Dec(J2000) = −5:23:22.9), an O6-type star that is the dominant ionization source of M 42 (O’Dell & Yusef-Zadeh 2000). The pink, green, and black circles represent the beams of TMRT in Ka, Ku, and Q bands, respectively (Sect. 2).