TMRT OBSERVATIONS OF CARBON-CHAIN MOLECULES IN SERPENS SOUTH 1a
- Department of Radio Science and Technology, Shanghai Astronomical Observatory, 80 Nandan RD, Shanghai 200030 (China)
We report Shanghai Tian Ma Radio Telescope (TMRT) detections of several long carbon-chain molecules in the C and Ku bands, including HC{sub 3}N, HC{sub 5}N, HC{sub 7}N, HC{sub 9}N, C{sub 3}S, C{sub 6}H, and C{sub 8}H toward the starless cloud Serpens South 1a. We detected some transitions (HC{sub 9}N J = 13–12, F = 12–11, and F = 14–13; H{sup 13}CCCN J = 2–1, F = 1–0, and F = 1–1; HC{sup 13}CCN J = 2–1, F = 2–2, F = 1–0, and F = 1–1; HCC{sup 13}CN J = 2–1, F = 1–0, and F = 1–1) and resolved some hyperfine components (HC{sub 5}N J = 6–5, F = 5–4; H{sup 13}CCCN J = 2–1, F = 2–1) for the first time in the interstellar medium. The column densities of these carbon-chain molecules in the range 10{sup 12}–10{sup 13} cm{sup −2} are comparable to two carbon-chain molecule rich sources, TMC-1 and Lupus-1A. The abundance ratios are 1.00:(1.11 ± 0.15):(1.47 ± 0.18) for [H{sup 13}CCCN]:[HC{sup 13}CCN]:[HCC{sup 13}CN]. This result implies that the {sup 13}C isotope is also concentrated in the carbon atom adjacent to the nitrogen atom in HC{sub 3}N in Serpens South 1a, which is similar to TMC-1. The [HC{sub 3}N]/[H{sup 13}CCCN] ratio of 78 ± 9, the [HC{sub 3}N]/[HC{sup 13}CCN] ratio of 70 ± 8, and the [HC{sub 3}N]/[HCC{sup 13}CN] ratio of 53 ± 4 are also comparable to those in TMC-1. Serpens South 1a proves to be a suitable testing ground for understanding carbon-chain chemistry.
- OSTI ID:
- 22666153
- Journal Information:
- Astrophysical Journal, Vol. 824, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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