Star-forming regions of the Aquila rift cloud complex. I. NH3 tracers of dense molecular cores

S.A. Levshakov,1,2,3 C. Henkel,4,5 D. Reimers,2 M. Wang6

1Ioffe Physical-Technical Institute, Polytekhnicheskaya Str. 26, 194021, St. Petersburg, Russia
2Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029, Hamburg, Germany
3St. Petersburg Electrotechnical University "LETI", Prof. Popov Str. 5, 197376, St. Petersburg, Russia
4Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121, Bonn, Germany
5Astronomy Department, King Abdulaziz University, PO Box 80203, 21589, Jeddah, Saudi Arabia
6Purple Mountain Observatory, Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Nanjing, 210008, PR China

From observations at the Effelsberg 100-m telescope, we intend to derive statistical properties of stochastic gas motion inside the dense molecular cores traced by NH3(1,1) and (2,2) emission lines. For the first time we found oscillating autocorrelation functions (ACFs) of the gas motion which eventually decay to zero with increasing lags on the scale 0.04 pc < l < 0.5 pc. The current paradigm supposes that the star formation process is controlled by the interplay between gravitation and turbulence, the latter preventing molecular cores from a quick collapse due to their own gravity. Thus, oscillating ACFs may indicate a damping of the developed turbulent flows surrounding the dense but less turbulent core - a transition to dominating gravitational forces and, hence, to gravitational collapse.


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