Distribution of CCS and HC3 N in L1147, an early phase dark cloud.
SUZUKI T., OHISHI M. and HIROTA T.
Abstract (from CDS):
We used the Nobeyama 45 m radio telescope to reveal spatial distributions of CCS and HC3 N in L1147, one of the carbon-chain producing region (CCPR) candidates, where carbon-chain molecules are dominant rather than NH3. We found that three cores (two CCS cores and one HC3N core), which are away from a very low luminosity object (a source that may turn into a sub-stellar mass brown dwarf), exist along the NE-SW filament traced by the 850 µm dust continuum. The column densities of CCS are 3-7x1012/cm2 and those of HC3N are 2-6x1012/cm2, respectively, much lower than those previously reported toward other CCPRs. We also found that two CCS peaks are displaced from the peaks of HC3N. In order to interpret such interleaved distributions, we conducted chemical reaction network simulations and found that slightly different gas densities could lead to large variation of the CCS-to-HC3N ratio in the early phase of dark cloud evolution. Such a chemical "variation" may be seen in other CCPRs. Finally, we were able to confirm that the L1147 filament can be regarded as a CCPR.
ISM: individual: L1147 - ISM: molecules - radio lines: ISM