Detection of Two Carbon-Chain-Rich Cores; CB130-3 and L673-SMM4

Abstract

We have found two dense cores, CB130-3 and L673-SMM4, where the carbon-chain molecules are extremely abundant relative to NH${}_3$, during a survey observation of radio emission lines of CCS, HC${}_3$N, HC${}_5$N, and NH${}_3$ toward dark cloud cores. Judging from the low NH${}_3$/CCS ratios, they are possible candidates for "Carbon-Chain--Producing Regions (CCPRs)" recognized as chemically young dark cloud cores. The deuterium fractionation ratios DNC/HN${}^{13}$C in CB130-3 and L673-SMM4 are found to be 1.28${}_{-0.05}^{+0.27}$ and 1.96${}_{-0.01}^{+0.32}$, respectively, which are comparable to or slightly higher than those in CCPRs found previously. We suggest that the dense cores of CB130-3 and L673-SMM4 are analogous to CCPRs but their chemical evolutionary phase would be slightly older than those of the dense cores in the Taurus region.

21 pages, 7 figures, accepted for publication in ApJ Part 1

References in corpus (3)

• The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
• Molecular Line Observations of a Carbon-Chain-Rich Core L492
• Depletion of CCS in a Candidate Warm-Carbon-Chain-Chemistry Source L483

Cited by in corpus (4)

• Z45: A New 45-GHz Band Dual-Polarization HEMT Receiver for the NRO 45-m Radio Telescope
• ALMA Observations of the IRDC Clump G34.43+00.24 MM3: DNC/HNC Ratio
• The Cosmic Evolution of Halo Pairs: I. Global Trends
• A particular carbon-chain-producing region: L1489 starless core