W51 IRS2中小质量恒星形成系统CG1的物理化学性质

楚雄师范学院学报 ›› 2025, Vol. 40 ›› Issue (3): 44-49.

W51 IRS2中小质量恒星形成系统CG1的物理化学性质

唐孟尧, 陶林钰^#, 李如凯, 黄皓, 李娟

楚雄师范学院物理与电气能源工程学院,云南楚雄 675000

收稿日期:2025-01-20 出版日期:2025-05-20 发布日期:2025-07-01
作者简介:唐孟尧（1994–）,男,博士,副教授,研究方向为大质量恒星形成、星际分子证认、天体化学。
^#共同第一作者：陶林钰。
基金资助:
国家自然科学基金项目（No. 12203011）,楚雄师范学院大学生创新创业训练计划项目

Physical and Chemical Properties of the Low-mass Star-forming System CG1 in W51 IRS2

TANG Mengyao, TAO Linyu^#, LI Rukai, HUANG Hao, LI Juan

School of Physics, Electrical and Energy Engineering, Chuxiong Normal University, Chuxiong, Yunnan Province 675000

Received:2025-01-20 Online:2025-05-20 Published:2025-07-01

摘要/Abstract

摘要： 基于ALMA望远镜在1.3 mm和3 mm波段的高分辨率观测数据,对大质量恒星形成区W51 IRS2中的小质量恒星形成系统进行了搜寻和高分辨率的观测研究。首次发现其中一个小质量恒星形成系统CG1。通过连续谱观测数据,发现CG1系统质量为1.4~4.2 M_⊙,具有典型的热辐射谱指数（α = 2~3.5）特征。基于局部热动平衡假设,在两个波段的谱线数据中证认出了17种星际分子,并精确计算其气体温度（245~579 K）、柱密度（10¹⁵~10¹⁸ cm^-2）和相对丰度（10^-9~10^-6）等物理参数。首次揭示了大质量恒星形成区W51 IRS2中孤立小质量系统CG1的物理化学性质,为恒星形成理论研究工作提供了关键观测依据。

关键词: 小质量恒星形成, 星际介质, 分子谱线

Abstract: Based on high-resolution observational data from the ALMA telescope at the 1.3 mm and 3 mm bands, we conducted a search and high-resolution study of low-mass star-forming systems within the massive star-forming region W51 IRS2. For the first time, a low-mass star-forming system CG1 was discovered in this region. Through continuum observations, the mass of the CG1 system, determined to be 1.4-4.2 M⊙, exhibits characteristic thermal radiation spectral indices (α=2-3.5). Using the MADCUBA software under the local thermodynamic equilibrium assumption, we successfully identified 17 interstellar molecular species in the spectral line data from both bands and precisely calculated physical parameters of gas temperature (245-579 K), column density (1015-1018 cm^-2), and relative abundance (10-9-10-6). This study revealed the physical and chemical properties of an isolated low-mass system within the massive star-forming region W51 IRS2 for the first time, providing critical observational evidence for theoretical research on star formation.

Key words: low-mass star formation, interstellar medium, molecular spectrum

中图分类号:

唐孟尧, 陶林钰, 李如凯, 黄皓, 李娟. W51 IRS2中小质量恒星形成系统CG1的物理化学性质[J]. 楚雄师范学院学报, 2025, 40(3): 44-49.

TANG Mengyao, TAO Linyu, LI Rukai, HUANG Hao, LI Juan. Physical and Chemical Properties of the Low-mass Star-forming System CG1 in W51 IRS2[J]. Journal of Chuxiong Normal University, 2025, 40(3): 44-49.