W 51 IRS 2中热抑制致密结构的物理化学性质研究

楚雄师范学院学报 ›› 2024, Vol. 39 ›› Issue (3): 16-21.

W 51 IRS 2中热抑制致密结构的物理化学性质研究

唐孟尧^1,2,*, 阮梦², 陈兴鹏², 杨蝴蝶², 李连登²

1.楚雄师范学院天体物理研究所,云南楚雄 675000;
2.楚雄师范学院物理与电子科学学院,云南楚雄 675000

收稿日期:2023-11-13 出版日期:2024-05-20 发布日期:2024-06-05
通讯作者: *唐孟尧（1994–）,男,博士,讲师,研究方向为大质量恒星形成、星际分子证认、天体化学等。E-mail： mengyao_tang@yeah.net,Tel. 15284440458
作者简介:^#共同第一作者：阮梦。
基金资助:
大学生创新创业训练计划项目（No. 202211391031）; 国家自然科学基金（No. 12203011）

Study on the Physical and Chemical Properties of a Thermally Inhibited Dense Structure in W51 IRS2

TANG Mengyao^1,2, RUAN Meng², CHEN Xingpeng², YANG Hudie², LI Liandeng²

1. Institute of Astrophysics, Chuxiong Normal University, Chuxiong, Yunnan Province 675000;
2. School of Physics and Electronic Science, Chuxiong Normal University, Chuxiong, Yunnan Province 675000

Received:2023-11-13 Online:2024-05-20 Published:2024-06-05

摘要/Abstract

摘要： 本文通过分析和处理ALMA望远镜对大质量恒星形成区W 51 IRS 2区域的超高分辨率（0.028角秒）观测数据,首次观测到了一个未发生碎裂的超致密团块状结构CE 1。其质量大于13倍太阳质量,密度高于10⁷。在CE I中探测到了CH₃CN分子的振动态（v 8=1）和转动态（v=0）总计16条跃迁谱线,并计算了CH₃CN分子的参数。通过金斯分析,发现CE1内部的实际温度应该高于400 K,在其内部并未观测到明显的恒星形成活动,所有研究结果表明CE 1极有可能是一个处于演化极早期阶段的大质量恒星“胚胎”。

关键词: 大质量恒星形成, 星际介质, 分子谱线

Abstract: This work analyzes and processes high-resolution (0.028'') observation data of the W51 IRS2 region, a massive star-forming region, obtained by the ALMA. For the first time, an unfragmented, ultra-dense clump-like structure called CE1 was observed, with a mass greater than 13 solar masses and a density higher than 107. Vibrational (v8=1) and rotational (v=0) transitions of CH₃CN molecule were detected in a total of 16 spectral transitions, and the parameters of CH₃CN were calculated. From Jeans analysis, it was found that the temperature inside CE 1 should be higher than 400 K, and no obvious star formation activity was observed inside. All the research results suggest that CE 1 is highly possible an “embryo” in a very early evolutionary stage of massive star formation.

Key words: massive star formation, interstellar medium, molecular spectrum

中图分类号:

P152

唐孟尧, 阮梦, 陈兴鹏, 杨蝴蝶, 李连登. W 51 IRS 2中热抑制致密结构的物理化学性质研究[J]. 楚雄师范学院学报, 2024, 39(3): 16-21.

TANG Mengyao, RUAN Meng, CHEN Xingpeng, YANG Hudie, LI Liandeng. Study on the Physical and Chemical Properties of a Thermally Inhibited Dense Structure in W51 IRS2[J]. Journal of Chuxiong Normal University, 2024, 39(3): 16-21.

参考文献

[1] Bergin E A, Tafalla M.Cold dark clouds: the initial conditions for star formation[J]. Annual Review of Astronomy & Astrophysics, 2007, 45, 339B.
[2] Myers P C, Fuller G A, Goodman A A, et al. Dense cores in dark clouds. VI. shapes[J]. Astrophysical Journal, 1991, 376, 561-572.
[3] Zinnecker H, Yorke H W.Toward understanding massive star formation[J]. Annual Review of Astronomy & Astrophysics, 2007, 45, 481.
[4] Bonnell I A, Bate M R, Clarke C J, et al. Competitive accretion in embedded stellar clusters[J]. Monthly Notices of Royal Astronomical Society, 2001, 323, 785-794.
[5] Padoan P, Pan L, Juvela M, et al. The origin of massive stars: the inertial-inflow model[J]. The Astrophysical Journal, 2020, 900, 82.
[6] McMullin J P, Waters B, Schiebel D, ,et al. CASA Architecture. CASA Architecture and Applications [C].2007, ASP Conference.Series. 376, 127-130.
[7] Ginsburg A, Ciriaco G, diederik k j, et al. Thermal feedback in the high-mass star and cluster-forming region W 51[J]. The Astrophysical Journal, 2017, 842: 92.
[8] Rong J, Qin S L, Zapata L A, et al. Complex molecules in the W51 North region[J]. Monthly Notices of Royal Astronomical Society, 2016, 455, 1428-1437.
[9] Reid M J, Menten K M, Brunthaler A, ,et al. Trigonometric parallaxes of high-mass star-forming regions: our view of the milky way [J]. The Astrophysical Journal. Trigonometric parallaxes of high-mass star-forming regions: our view of the milky way [J]. The Astrophysical Journal, 2019, 885, 131 R.
[10] Tang M, Palau A, Zapata A L, ,et al. W51North: a protocluster emerging out of a thermally inhibited fragmenting cloud [J]. Astronomy & Astrophysics. W51North: a protocluster emerging out of a thermally inhibited fragmenting cloud [J]. Astronomy & Astrophysics, 2022, 657, A 30.
[11] Ossenkopf V, Henning T.Dust opacities for protostellar cores[J]. Astronomy & Astrophysics, 1994, 291, 943-959.
[12] Möller T, Endres C, Schike P.EXtended CASA line analysis software suite (XCLASS)[J]. Astronomy & Astrophysics, 2017, 598, A7.
[13] Müller H S P, Thorwirth S, Roth D A, et al. The cologne database for molecular spectroscopy [J]. Astronomy & Astrophysics, 2001, 370, L49-L52.
[14] Sahu D, Liu S Y, Liu T, et al. Alma survey of orion planck galactic cold clumps (ALMASOP): detection of extremely high-density compact structure of prestellar cores and multiple substructures within[J]. The Astrophysical Journal, 2021, 907, L15-L24.