TY - JOUR
T1 - Carbon isotope fractionation and depletion in TMC1
AU - Liszt, H. S.
AU - Ziurys, L. M.
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2012/3/1
Y1 - 2012/3/1
N2 - 12C/13C isotopologue abundance anomalies have long been predicted for gas-phase chemistry in molecules other than CO and have recently been observed in the Taurus molecular cloud (TMC) in several species hosting more than one carbon atom, i.e., CCH, CCS, CCCS, and HC3N. Here we work to ascertain whether these isotopologic anomalies actually result from the predicted depletion of the 13C+ ion in an oxygen-rich optically shielded dense gas, or from some other more particular mechanism or mechanisms. We observed λ3mm emission from carbon-, sulfur-, and nitrogen-bearing isotopologues of HNC, CS, and H2CS at three positions in Taurus (TMC1, L1527, and the NH3 peak) using the ARO 12 m telescope. We saw no evidence of 12C/13C anomalies in our observations. Although the pool of C+ is likely to be depleted in 13C, 13C is not depleted in the general pool of carbon outside CO, which probably exists mostly in the form of C0. The observed isotopologic abundance anomalies are peculiar to those species in which they are found.
AB - 12C/13C isotopologue abundance anomalies have long been predicted for gas-phase chemistry in molecules other than CO and have recently been observed in the Taurus molecular cloud (TMC) in several species hosting more than one carbon atom, i.e., CCH, CCS, CCCS, and HC3N. Here we work to ascertain whether these isotopologic anomalies actually result from the predicted depletion of the 13C+ ion in an oxygen-rich optically shielded dense gas, or from some other more particular mechanism or mechanisms. We observed λ3mm emission from carbon-, sulfur-, and nitrogen-bearing isotopologues of HNC, CS, and H2CS at three positions in Taurus (TMC1, L1527, and the NH3 peak) using the ARO 12 m telescope. We saw no evidence of 12C/13C anomalies in our observations. Although the pool of C+ is likely to be depleted in 13C, 13C is not depleted in the general pool of carbon outside CO, which probably exists mostly in the form of C0. The observed isotopologic abundance anomalies are peculiar to those species in which they are found.
KW - ISM: clouds
KW - ISM: molecules
KW - astrochemistry
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U2 - 10.1088/0004-637X/747/1/55
DO - 10.1088/0004-637X/747/1/55
M3 - Article
AN - SCOPUS:84857246205
VL - 747
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 55
ER -