Detection of Two Carbon-Chain-Rich Cores; CB130-3 and L673-SMM4
  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$^{+0.27}_{-0.05}$ and 1.96$^{+0.32}_{-0.01}$, 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. 
Tomoya Hirota, Takeshi Sakai, Nami Sakai, and Satoshi Yamamoto
astro-ph.SR