تقرير
A study of the C$_3$H$_2$ isomers and isotopologues: first interstellar detection of HDCCC
| العنوان: | A study of the C$_3$H$_2$ isomers and isotopologues: first interstellar detection of HDCCC |
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| المؤلفون: | Spezzano, S., Gupta, H., Brünken, S., Gottlieb, C. A., Caselli, P., Menten, K. M., Müller, H. S. P., Bizzocchi, L., Schilke, P., McCarthy, M. C., Schlemmer, S. |
| المصدر: | A&A 586, A110 (2016) |
| سنة النشر: | 2015 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | The partially deuterated linear isomer HDCCC of the ubiquitous cyclic carbene ($c$-C$_3$H$_2$) was observed in the starless cores TMC-1C and L1544 at 96.9 GHz, and a confirming line was observed in TMC-1 at 19.38 GHz. To aid the identification in these narrow line sources, four centimetre-wave rotational transitions (two in the previously reported $K_a =0$ ladder, and two new ones in the $K_a =1$ ladder), and 23 transitions in the millimetre band between 96 and 272 GHz were measured in high-resolution laboratory spectra. Nine spectroscopic constants in a standard asymmetric top Hamiltonian allow the principal transitions of astronomical interest in the $K_a \le 3$ rotational ladders to be calculated to within 0.1 km s$^{-1}$ in radial velocity up to 400 GHz. Conclusive evidence for the identification of the two astronomical lines of HDCCC was provided by the $V_{\rm{LSR}}$ which is the same as that of the normal isotopic species (H$_2$CCC) in the three narrow line sources. In these sources, deuterium fractionation in singly substituted H$_2$CCC (HDCCC/H$_2$CCC $\sim4\%\text{-}19\%$) is comparable to that in $c$-C$_3$H$_2$ ($c$-C$_3$H$_2$/$c$-C$_3$HD $\sim5\%\text{-}17\%$), and similarly in doubly deuterated $c$-C$_3$H$_2$ ($c$-C$_3$D$_2$/$c$-C$_3$HD $\sim3\%\text{-}17\%$), implying that the efficiency of the deuteration processes in the H$_2$CCC and $c$-C$_3$H$_2$ isomers are comparable in dark clouds. Comment: Accepted for publication in A&A |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1051/0004-6361/201527460 |
| URL الوصول: | http://arxiv.org/abs/1511.04878 |
| رقم الأكسشن: | edsarx.1511.04878 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1051/0004-6361/201527460 |
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