Catching the Birth of a Dark Molecular Cloud for the First Time

doi:10.3847/1538-4357/aad571

CORC > 国家天文台 > 中国科学院国家天文台

	Catching the Birth of a Dark Molecular Cloud for the First Time
	Zuo, Pei 2,3,4; Li, Di 2,3,4; Peek, J. E. G.1,5; Chang, Qiang 6; Zhang, Xia 6; Chapman, Nicholas 7; Goldsmith, Paul F.8; Zhang, Zhi-Yu 9,10
刊名	ASTROPHYSICAL JOURNAL
	2018-11-01
卷号	867 期号:1 页码:7
关键词	ISM: atoms ISM: clouds ISM: molecules
ISSN号	0004-637X
DOI	10.3847/1538-4357/aad571
英文摘要	The majority of hydrogen in the interstellar medium (ISM) is in atomic form. The transition from atoms to molecules and, in particular, the formation of the H-2 molecule, is a key step in cosmic structure formation en route to stars. Quantifying H-2 formation in space is difficult, due to the confusion in the emission of atomic hydrogen (H I) and the lack of a H-2 signal from the cold ISM. Here we present the discovery of a rare, isolated dark cloud currently undergoing H-2 formation, as evidenced by a prominent "ring" of H I. self-absorption. Through a combined analysis of H I. narrow self-absorption, CO emission, dust emission, and extinction, we directly measured, for the first time, the [H I]/[H-2] abundance varying from 2% to 0.2%, within one region. These measured H I. abundances are orders of magnitude higher than usually assumed initial conditions for protoplanetary disk models. None of the fast cloud formation model could produce such low atomic hydrogen abundance. We derived a cloud formation timescale of similar to 6 x 10(6) years, consistent with the global Galactic star formation rate, and favoring the classical star formation picture over fast star formation models. Our measurements also help constrain the H-2 formation rate, under various ISM conditions.
资助项目	National Key R&D Program of China[2017YFA0402600] ; National Natural Science Foundation of China[11725313] ; National Natural Science Foundation of China[11690024] ; International Partnership Program of Chinese Academy of Sciences[114A11KYSB20160008] ; National Science Foundation[AST-1100968] ; CAS Interdisciplinary Innovation Team" program ; ERC[321302]
WOS关键词	NARROW SELF-ABSORPTION ; TRANSLUCENT SIGHT LINES ; COLD ATOMIC-HYDROGEN ; STAR-FORMATION ; GALAXY ; ABUNDANCES ; CARBON ; CORES
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	IOP PUBLISHING LTD
WOS记录号	WOS:000448448800013
资助机构	National Key R&D Program of China ; National Key R&D Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; International Partnership Program of Chinese Academy of Sciences ; International Partnership Program of Chinese Academy of Sciences ; National Science Foundation ; National Science Foundation ; CAS Interdisciplinary Innovation Team" program ; CAS Interdisciplinary Innovation Team" program ; ERC ; ERC ; National Key R&D Program of China ; National Key R&D Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; International Partnership Program of Chinese Academy of Sciences ; International Partnership Program of Chinese Academy of Sciences ; National Science Foundation ; National Science Foundation ; CAS Interdisciplinary Innovation Team" program ; CAS Interdisciplinary Innovation Team" program ; ERC ; ERC ; National Key R&D Program of China ; National Key R&D Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; International Partnership Program of Chinese Academy of Sciences ; International Partnership Program of Chinese Academy of Sciences ; National Science Foundation ; National Science Foundation ; CAS Interdisciplinary Innovation Team" program ; CAS Interdisciplinary Innovation Team" program ; ERC ; ERC ; National Key R&D Program of China ; National Key R&D Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; International Partnership Program of Chinese Academy of Sciences ; International Partnership Program of Chinese Academy of Sciences ; National Science Foundation ; National Science Foundation ; CAS Interdisciplinary Innovation Team" program ; CAS Interdisciplinary Innovation Team" program ; ERC ; ERC
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/23158]
专题	中国科学院国家天文台
通讯作者	Zuo, Pei
作者单位	1.Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA 2.Chinese Acad Sci, Natl Astron Observ, Datun Rd, Beijing 100101, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.Chinese Acad Sci, CAS Key Lab FAST, NAOC, Beijing 100101, Peoples R China 5.Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA 6.Chinese Acad Sci, Xinjiang Astron Observ, 150 Sci 1 St, Urumqi 830011, Xinjiang, Peoples R China 7.Northwestern Univ, CIERA, 2145 Sheridan Rd, Evanston, IL 60208 USA 8.CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA 9.Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland 10.ESO, Karl Schwarzschild Str 2, D-85748 Munich, Germany
推荐引用方式 GB/T 7714	Zuo, Pei,Li, Di,Peek, J. E. G.,et al. Catching the Birth of a Dark Molecular Cloud for the First Time[J]. ASTROPHYSICAL JOURNAL,2018,867(1):7.
APA	Zuo, Pei.,Li, Di.,Peek, J. E. G..,Chang, Qiang.,Zhang, Xia.,...&Zhang, Zhi-Yu.(2018).Catching the Birth of a Dark Molecular Cloud for the First Time.ASTROPHYSICAL JOURNAL,867(1),7.
MLA	Zuo, Pei,et al."Catching the Birth of a Dark Molecular Cloud for the First Time".ASTROPHYSICAL JOURNAL 867.1(2018):7.