A (CO)-C-12, (CO)-C-13, and (CO)-O-18 survey of infrared dark clouds

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 分子云与恒星形成研究团组

	A (CO)-C-12, (CO)-C-13, and (CO)-O-18 survey of infrared dark clouds
	Du, Fujun; Yang, Ji
刊名	ASTROPHYSICAL JOURNAL
	2008-10-10
卷号	686 期号:1 页码:384-398
关键词	dust extinction Galaxy : structure infrared : ISM radio lines : ISM stars : formation
ISSN号	0004-637X
英文摘要	Infrared dark clouds (IRDCs) are extinction features against the Galactic infrared background, mainly in themid-infrared band. Recently they were proposed to be potential sites of massive star formation. In this work we have made a (CO)-C-12, (CO)-C-13, and (CO)-O-18 (J = 1 -> 0) survey of 61 IRDCs, 52 of which are in the first Galactic quadrant, selected from a catalog given by Simon and coworkers, while the others are in the outer Galaxy, selected by visually inspecting the MSX images. Detection rates in the three CO lines are 90%, 71%, and 62%, respectively. The distribution of IRDCs in the first Galactic quadrant is consistent with the 5 kpc molecular ring picture, while a slight trace of a spiral pattern is also noticeable, and needs to be further examined. The IRDCs have a typical excitation temperature of 10 K and typical column density of several 10(22) cm(-2). Their typical physical size is estimated to be several parsecs using angular sizes from the Simon catalog. Typical volume density and typical LTE mass are similar to 5000 cm(-3) and similar to 5000 M-circle dot, respectively. The IRDCs are in or near virial equilibrium. The properties of IRDCs are similar to those of star-forming molecular clumps, and they seem to be intermediate between giant molecular clouds and Bok globules; thus they may represent early stages of massive star formation.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	1ST GALACTIC QUADRANT ; MOLECULAR CLOUDS ; CARBON-MONOXIDE ; DENSE CORES ; MILKY-WAY ; ROTATION CURVE ; COMPLEXES ; GALAXY ; EXTINCTION ; PRECURSORS
收录类别	SCI
语种	英语
WOS记录号	WOS:000259822200030
公开日期	2011-12-29
内容类型	期刊论文
源URL	[http://159.226.72.40/handle/332002/1837]
专题	紫金山天文台_分子云与恒星形成研究团组
作者单位	Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China
推荐引用方式 GB/T 7714	Du, Fujun,Yang, Ji. A (CO)-C-12, (CO)-C-13, and (CO)-O-18 survey of infrared dark clouds[J]. ASTROPHYSICAL JOURNAL,2008,686(1):384-398.
APA	Du, Fujun,&Yang, Ji.(2008).A (CO)-C-12, (CO)-C-13, and (CO)-O-18 survey of infrared dark clouds.ASTROPHYSICAL JOURNAL,686(1),384-398.
MLA	Du, Fujun,et al."A (CO)-C-12, (CO)-C-13, and (CO)-O-18 survey of infrared dark clouds".ASTROPHYSICAL JOURNAL 686.1(2008):384-398.