1 research outputs found
Carbon-Chain Molecules in Molecular Outflows and Lupus I Region--New Producing Region and New Forming Mechanism
Using the new equipment of the Shanghai Tian Ma Radio Telescope, we have
searched for carbon-chain molecules (CCMs) towards five outflow sources and six
Lupus I starless dust cores, including one region known to be characterized by
warm carbon-chain chemistry (WCCC), Lupus I-1 (IRAS 15398-3359), and one TMC-1
like cloud, Lupus I-6 (Lupus-1A). Lines of HC3N J=2-1, HC5N J=6-5, HC7N
J=14-13, 15-14, 16-15 and C3S J=3-2 were detected in all the targets except in
the outflow source L1660 and the starless dust core Lupus I-3/4. The column
densities of nitrogen-bearing species range from 10 to 10
cm and those of CS are about 10 cm. Two outflow
sources, I20582+7724 and L1221, could be identified as new
carbon-chain--producing regions. Four of the Lupus I dust cores are newly
identified as early quiescent and dark carbon-chain--producing regions similar
to Lup I-6, which together with the WCCC source, Lup I-1, indicate that
carbon-chain-producing regions are popular in Lupus I which can be regard as a
Taurus like molecular cloud complex in our Galaxy. The column densities of C3S
are larger than those of HC7N in the three outflow sources I20582, L1221 and
L1251A. Shocked carbon-chain chemistry (SCCC) is proposed to explain the
abnormal high abundances of C3S compared with those of nitrogen-bearing CCMs.
Gas-grain chemical models support the idea that shocks can fuel the environment
of those sources with enough thus driving the generation of S-bearing
CCMs.Comment: 7 figures, 8 tables, accepted by MNRA