Japan Geoscience Union Meeting 2016

Presentation information


Symbol P (Space and Planetary Sciences) » P-PS Planetary Sciences

[P-PS14] Origin and evolution of materials in space

Wed. May 25, 2016 10:45 AM - 12:00 PM 104 (1F)

Convener:*Shogo Tachibana(Department of Natural History Scieces, Hokkaido University), Hitoshi Miura(Graduate School of Natural Sciences, Department of Information and Biological Sciences, Nagoya City University), Takafumi Ootsubo(Graduate School of Arts and Sciences, University of Tokyo), Chair:Hitoshi Miura(Graduate School of Natural Sciences, Department of Information and Biological Sciences, Nagoya City University)

11:00 AM - 11:15 AM

[PPS14-07] The precise determination of the 13C isotopic ratios for carbon chain molecule HC3N in the low-mass star forming region L1527 by radio observations

*Mitsunori Araki1, SHURO TAKANO2, NAMI SAKAI3, SATOSHI YAMAMOTO4, TAKAHIRO OYAMA1, NOBUHIKO KUZE5, KOICHI TSUKIYAMA1 (1.Infrared Free Electron Laser Research Center, Tokyo University of Science, 2.Nihon University, 3.The Institute of Physical and Chemical Research (RIKEN), 4.The University of Tokyo, 5.Sophia University)

Keywords:radio, carbon chain molecule, isotopic ratio

Linear carbon chains have been found in dark clouds. Recently a lot of carbon chains have also been detected in the class 0 object L1527, which is a low-mass star forming region. We observed the normal and isotopic species of the fundamental carbon-chain molecule HC3N in L1527 with the high signal-to-noise ratios using Green Bank 100 m telescope and Nobeyama 45 m telescope to explore the production scheme of HC3N in the region having a warm carbon chain chemistry (WCCC). The spectral lines of the rotational transitions in the 44–109 GHz region were used to study the abundances of the normal and isotopic species. The ratios were precisely determined to be 1.00 : 1.01 ± 0.03 : 1.35 ± 0.04 : 86.4 ± 2.2 for [H13CCCN] : [HC13CCN] : [HCC13CN] : [HCCCN], where the errors are in one standard deviations. The ratios of [HCC13CN]/[HCCC15N] and [HCCCN]/[HCCC15N] were obtained to be 5.26 ± 0.24 and 338 ± 15, respectively. It was found that the abundance of H13CCCN is almost equal to that of HC13CCN, and it was concluded that HC3N in L1527 is mainly formed by the reaction schemes via C2H2 and C2H2+, i.e. dicarbide chemistry. The obtained ratios are quite similar to those reported in the cyanopolyyne peak in the starless dark cloud Taurus Molecular Cloud-1 [2]. Thus this similarity would suggest a universality of dicarbide chemistry producing HC3N irrespective of evolutional phases from a starless dark cloud to a class 0 object for a low-mass star forming region.
[1] Sakai, N., Sakai, T., Hirota, T., & Yamamoto, S. 2008, ApJ, 672, 371
[2] Takano, S., Masuda, A., Hirahara, Y., et al. 1998, A&A, 329, 1156