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| EPoS Contribution |
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Dense Gas and Star Formation in the Ophiuchus B2 Core
James Di Francesco National Research Council of Canada (NRC-HIA), Victoria, Canada | |
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We present the first results of combined single-dish and interferometric NH3 mapping of cold, dense star forming filaments in the nearby Ophiuchus molecular cloud. Continuum dust emission has been mapped extensively at (sub)millimetre wavelengths within the cloud, revealing a highly fragmented and clumped complex containing both starless and protostellar cores. The Oph B filament, containing ~ 50 solar masses of gas in two distinct substructures, has a low surface density of YSOs, a relatively flat column density profile (seen in dust emission) and large numbers of starless cores relative to the other filaments. Consequently, it is one of the least evolved dense filaments in Ophiuchus.
Our single dish NH3 (1,1) and (2,2) maps made at the Green Bank Telescope probe the density and temperature structure of Oph B at a spatial resolution of ~ 32", and kinematics with high spectral resolution. Complementary interferometer observations using the Australia Telescope Compact Array reveal physical characteristics of small (~ 10", or ~ 2000 AU), solar-mass sized condensations within the larger filament structure. Surprisingly, most of the small-scale features seen in the NH3 data do not correlate with the brightest continuum emission peaks. This result contrasts with the correlation normally found between dust continuum and emission from N-based molecules in isolated dense cores. | |