Low-resolution observations in OMC-3. From left to right and from top to bottom we plot (a) Herschel, total gas column density, N(H₂) (36″); (b) WISE 3.4 μm emission (6.1″); (c) gas kinetic temperature, T_K, (d) N₂H⁺ (1–0), (e) HNC (1–0), and (f) HC₃N (10–9) integrated intensity maps obtained in our IRAM-30 m (broad) observations (30″). The symbols are similar to those in Fig. 1. The corresponding beam size and scale bar are indicated in the lower corner of each panel. For reference, panel a includes contours at N(H₂) = [15, 50, 100, 150, 200] ×10²¹ cm⁻² and the footprint of our ALMA observations shown in Fig. 8. Similar plots for all the other regions can be found in Appendix B.