W51 Main NH_3_ and CH_3_OH data cubes

The main goal is to characterize kinematics and physical conditions of (hot and dense) circumstellar molecular gas around O-type young stars. We want to map at subarcsecond resolution highly excited inversion lines of NH_3_ in the high-mass star-forming region W51 Main (distance = 5.4kpc), which is an ideal target to constrain theoretical models of high-mass star formation.

Using the Karl Jansky Very Large Array (JVLA), we mapped the hot and dense molecular gas in W51 Main with ~0.2"-0.3" angular resolution in five metastable (J = K) inversion transitions of ammonia (NH_3_): (J,K) = (6, 6), (7, 7), (9, 9), (10, 10), and (13, 13). These lines arise from energy levels between ~400K and ~1700K above the ground state. We also made maps of the (free-free) continuum emission at frequencies between 25 and 36GHz.