First Results from a 1.3 cm EVLA Survey of Massive Protostellar Objects:
  G35.03+0.35
  We have performed a 1.3 centimeter survey of 24 massive young stellar objects
(MYSOs) using the Expanded Very Large Array (EVLA). The sources in the sample
exhibit a broad range of massive star formation signposts including Infrared
Dark Clouds (IRDCs), UCHII regions, and extended 4.5 micron 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 ammonia (1,1) through (6,6) inversion lines, four methanol transitions,
two H recombination lines, plus continuum at 0.05 pc resolution. We find three
areas of thermal ammonia emission, two within the EGO (designated the NE and SW
cores) and one toward an adjacent IRDC. The NE core contains an UCHII region
(CM1) and a candidate HCHII region (CM2). A region of non-thermal, likely
masing ammonia (3,3) and (6,6) emission is coincident with an arc of 44 GHz
methanol masers. We also detect two new 25 GHz Class I methanol masers. A
complementary Submillimeter Array 1.3 mm continuum image shows that the
distribution of dust emission is similar to the lower-lying ammonia lines, all
peaking to the NW of CM2, indicating the likely presence of an additional MYSO
in this protocluster. By modeling the ammonia and 1.3 mm continuum data, we
obtain gas temperatures of 20-220 K and masses of 20-130 solar. The diversity
of continuum emission properties and gas temperatures suggest that objects in a
range of evolutionary states exist concurrently in this protocluster.
