Discovery of Four New Massive and Dense Cold Cores

We report the identification, from a 1.2 mm dust continuum emission survey toward massive star-forming regions, of four strong 1.2 mm sources without counterparts at mid-infrared ( Midcourse Space Experiment [ MSX ]) and far-infrared ( IRAS ) wavelengths. They have radii in the range 0.2-0.3 pc, dust temperatures ≤17 K, masses in the range 4 × 10 2 -2 × 10 3 M ☉ , and densities of ~2 × 10 5 cm -3 . We suggest that these objects are massive and dense cold cores that will eventually collapse to form high-mass stars.