Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 1S012

Probing the Evolutionary Stages of Infrared Dark Cloud Cores

Sokolov, Vlas (Institute of Astronomy, National Tsing Hua University)
Chen, Vivien (Institute of Astronomy, National Tsing Hua University)
Liu, Sheng-Yuan (Institute of Astronomy & Astrophysics, Academia Sinica)
Su, Yu-Nung (Institute of Astronomy & Astrophysics, Academia Sinica)

Abstract:
Infrared dark clouds (IRDCs) are cold and dense extinction feature found against the diffuse Galactic infrared emission, and are thought to be the potential sites for massive star formation. They often harbour dense cores in different evolutionary stages that are differentiated by various evolutionary tracers such as luminosity, temperature, line width, or CO depletion. In this study, we derive gas temperature of 12 IRDC cores to complete the last portion of a large deuterium fractionation survey of 44 IRDC cores. We adopt existing infrared classification based on Spitzer/IRAC 3-8μm colours and Spitzer/MIPS 24μm point-source emission to discuss evolutionary stages of the cores in terms of “quiescent”, “intermediate”, “active”, and “red” types. We examine correlation between deuterium fractionation of N2H+ with several evolutionary tracers. A clear decreasing trend has been identified with gas temperature and line width.

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