2011ApJ...739L..16B

We have performed a 1.3 cm survey of 24 massive young stellar objects (MYSOs) using the Expanded Very Large Array. The sources in the sample exhibit a broad range of massive star formation signposts including infrared dark clouds (IRDCs), ultra-compact H II (UC H II) regions, and extended 4.5 µm emission in the form of extended green objects (EGOs). In this work, we present results for G35.03+0.35 which exhibits all of these phenomena. We simultaneously image the 1.3 cm NH₃(1,1) through (6,6) inversion lines, four CH₃OH transitions, two H recombination lines, plus continuum at 0.05 pc resolution. We find three areas of thermal NH₃emission, two within the EGO (designated as the NE and SW cores) and one toward an adjacent IRDC. The NE core contains a UC H II region (CM1) and a candidate hyper-compact H II region (CM2). A region of non-thermal, likely masing NH₃(3,3) and (6,6) emission is coincident with an arc of 44 GHz CH₃ OH masers. We also detect two new 25 GHz Class-I CH₃ OH masers. A complementary Submillimeter Array 1.3 mm continuum image shows that the distribution of dust emission is similar to the lower-lying NH₃lines, all peaking to the NW of CM2, indicating the likely presence of an additional MYSO in this protocluster. By modeling the NH₃ and 1.3 mm continuum data, we obtain gas temperatures of 20-220 K and masses of 20-130 M_☉. The diversity of continuum emission properties and gas temperatures suggests that objects in a range of evolutionary states exist concurrently in this protocluster.