Precise observations of the 12C/13C ratios of HC3N in the low-mass star-forming region L1527

Abstract

Using the Green Bank 100 m telescope and the Nobeyama 45 m telescope, we have observed the rotational emission lines of the three 13C isotopic species of HC3N in the 3 and 7 mm bands toward the low-mass star-forming region L1527 in order to explore their anomalous 12C/13C ratios. The column densities of the 13C isotopic species are derived from the intensities of the J = 5-4 lines observed at high signal-to-noise ratios. The abundance ratios are determined to be 1.00:1.01 +- 0.02:1.35 +- 0.03:86.4 +- 1.6 for [H13CCCN]:[HC13CCN]:[HCC13CN]:[HCCCN], where the errors represent one standard deviation. The ratios are very similar to those reported for the starless cloud, Taurus Molecular Cloud-1 Cyanopolyyne Peak (TMC-1 CP). These ratios cannot be explained by thermal equilibrium, but likely reflect the production pathways of this molecule. We have shown the equality of the abundances of H13CCCN and HC13CCN at a high-confidence level, which supports the production pathways of HC3N via C2H2 and C2H2+. The average 12C/13C ratio for HC3N is 77 +- 4, which may be only slightly higher than the elemental 12C/13C ratio. Dilution of the 13C isotope in HC3N is not as significant as that in CCH or c-C3H2. We have also simultaneously observed the DCCCN and HCCC15N lines and derived the isotope ratios: [DCCCN]/[HCCCN] = 0.0370 +- 0.0007 and [HCCCN]/[HCCC15N] = 338 +- 12.

arXiv comment3 figures, 4 tables, 20 pages

References in corpus (18)

• Molecular Evolution and Star Formation: From Prestellar Cores to Protostellar Cores
• Molecular Evolution in Collapsing Prestellar Cores
• Isotopic fractionation of carbon, deuterium and nitrogen : a full chemical study
• Modeling the Lukewarm Corino Phase - is L1527 unique?
• Nitrogen isotopic ratios in Barnard 1: a consistent study of the N2H+, NH3, CN, HCN and HNC isotopologues
• The 15N-enrichment in dark clouds and Solar System objects
• A Search for Carbon-Chain-Rich Cores in Dark Clouds
• Detection of (15)NNH+ in L1544: non-LTE modelling of dyazenilium hyperfine line emission and accurate (14)N/(15)N values
• The nature of the dense core population in the Pipe Nebula: A survey of NH3, CCS, and HC5N molecular line emission
• Detection of 15NH2D in dense cores: A new tool for measuring the 14N/15N ratio in the cold ISM
• Nitrogen Isotopic Fractionation in Interstellar Ammonia
• Carbon Isotope and Isotopomer Fractionation in Cold Dense Cloud Cores
• Observations of nitrogen isotope fractionation in deeply embedded protostars
• Implication of Formation Mechanisms of HC5N in TMC-1 as Studied by 13C Isotopic Fractionation
• TMRT Observations of Carbon-chain molecules in Serpens South 1A
• 13C Isotopic Fractionation of HC3N in Star-Forming Regions -Low-Mass Star Forming Region L1527 and High-Mass Star Forming Region G28.28-0.36-
• Detection of ${}^{13}C$ Isotopic Species of $H{C}_{7}N$
• Tracing the evolutionary stage of Bok globules: CCS and NH3

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