We present an unbiased λ 3 mm spectral line survey (between 84.5 and 115.8 GHz), conducted by the Purple Mountain Observatory 13.7 m radio telescope, together with updated modeling results, toward the carbon-rich asymptotic giant branch star IRC+10216 (CW Leo). A total of 75 spectral lines (96 transitions) are detected, and identified to arise from 19 molecules: C₂H, l-C₃H, C₄H, CN, C₃N, HC₃N, HC₅N, HCN, HNC, CH₃CN, MgNC, CO, c-C₃H₂, SiC₂, SiO, SiS, CS, C₂S, C₃S, and their isotopologues. Among them, one molecular emission line (H¹³CCCN J = 13–12) is discovered in IRC+10216 for the first time. The excitation temperature, column density, and fractional abundance of the detected species are deduced by assuming they are in local thermodynamic equilibrium. In addition, the isotopic ratios of [¹²C]/[¹³C], [³²S]/[³⁴S], [²⁸Si]/[²⁹Si], and [¹²C³⁴S]/[¹³C³²S] are obtained and found to be consistent with previous studies. Finally, we summarize all of the 106 species detected in IRC+10216 to date with their observed and modeled column densities for the convenience of future studies.

中文翻译：

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对富含碳的 AGB 星 IRC+10216 (CW Leo) 的星周包层进行 λ 3 mm 线测量

我们提出一个公正的λ由紫金山天文台13.7 m射电望远镜对富碳渐近巨星分支星IRC+10216（CW Leo）进行的3毫米谱线勘测（84.5至115.8 GHz之间）以及更新的建模结果。总共检测到 75 条谱线（96 个跃迁），并确定它们来自 19 个分子：C ₂ H、我-C ₃ H、C ₄ H、CN、C ₃ N、HC ₃ N、HC ₅ N、HCN、HNC、CH ₃ CN、MgNC、CO、C-C ₃ H ₂、SiC ₂、SiO、SiS、CS、C ₂ S、C ₃ S及其同位素异体。其中，1条分子发射线（H ¹³ CCCNJ= 13–12) 首次在 IRC+10216 中发现。通过假设检测到的物质处于局部热力学平衡，可以推导出激发温度、柱密度和丰度分数。另外，[ ¹² C]/[ ¹³ C]、[ ³² S]/[ ³⁴ S]、[ ²⁸ Si]/[ ²⁹ Si]和[ ¹² C ³⁴ S]/[ ¹³ C ³² S ]的同位素比] 得到并发现与之前的研究一致。最后，我们总结了迄今为止在 IRC+10216 中检测到的所有 106 个物种及其观察到的和模拟的柱密度，以方便将来的研究。