The precise radio observation of the 13c isotopic fractionation for carbon chain molecule HC3N in the low-mass star forming region l1527

We observed the three $^{13}$C isotopic species of HC$_{3}$N with the high signal-to-noise ratios in L1527 using Green Bank 100 m telescope and Nobeyama 45 m telescope to explore the production scheme of HC$_{3}$N, where L1527 is the low-mass star forming region in the phase of a warm carbon chain chemistry region.\footnote{Sakai, N., Sakai, T., Hirota, T., \& Yamamoto, S. 2008, ApJ, 672, 371} The spectral lines of the $J$ = 5--4, 9--8, 10--9, and 12--11 transitions in the 44–109 GHz region were used to measure isotopic ratios. The abundance of HCCCN was determined from the line intensities of the two weak hyperfine components of the $J$ = 5–4 transition. The isotopic ratios were precisely determined to be 1.00 : 1.01 : 1.35 : 86.4 for [H$^{13}$CCCN] : [HC$^{13}$CCN] : [HCC$^{13}$CN] : [HCCCN]. It was found that the abundance of H$^{13}$CCCN is equal to that of HC$^{13}$CCN, and it was implied that HC$_{3}$N is mainly formed by the reaction schemes via C$_{2}$H$_{2}$ and C$_{2}$H$_{2}^{+}$ in L1527. This would suggest a universality of dicarbide chemistry producing HC$_{3}$N irrespective of evolutional phases from a starless dark cloud\footnote{Takano, S., Masuda, A., Hirahara, Y., et al. 1998, A\&A, 329, 1156} to a warm carbon chain chemistry region