2010ApJ...715...18S

We present molecular line observations, made with angular resolutions of ∼20'', toward the filamentary infrared dark cloud G34.43+0.24 using the APEX [CO(3 -> 2), ¹³CO(3 -> 2), C¹⁸O(3 -> 2), and CS(7 -> 6) transitions], Nobeyama 45 m [CS(2 -> 1), SiO(2 -> 1), C³⁴S(2 -> 1), HCO⁺(1 -> 0), H¹³CO⁺(1 -> 0), and CH₃OH(2 -> 1) transitions], and SEST [CS(2 -> 1) and C¹⁸O(2 -> 1) transitions] telescopes. We find that the spatial distribution of the molecular emission is similar to that of the dust continuum emission observed with 11'' resolution showing a filamentary structure and four cores. The cores have local thermodynamic equilibrium masses ranging from 3.3x10² to 1.5x10³ M_☉ and virial masses from 1.1x10³ to 1.5x10³ M_☉, molecular hydrogen densities between 1.8x10⁴ and 3.9x10⁵ cm^–3, and column densities >2.0x10²² cm^–2, values characteristic of massive star-forming cores. The ¹³CO(3 -> 2) profile observed toward the most massive core reveals a blue profile indicating that the core is undergoing large-scale inward motion with an average infall velocity of 1.3 km/s and a mass infall rate of 1.8x10^–3 M_☉/yr. We report the discovery of a molecular outflow toward the northernmost core thought to be in a very early stage of evolution. We also detect the presence of high-velocity gas toward each of the other three cores, giving support to the hypothesis that the excess 4.5 µm emission ("green fuzzies") detected toward these cores is due to shocked gas. The molecular outflows are massive and energetic, with masses ranging from 25 to 80 M_☉, momentum 2.3-6.9x10² M_☉ km/s, and kinetic energies 1.1-3.6x10³ M_☉km2/s2, indicating that they are driven by luminous, high-mass young stellar objects.