(CO)-C-13, (CO)-O-18, and CS observations toward massive dense cores

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

	(CO)-C-13, (CO)-O-18, and CS observations toward massive dense cores
	Ao, YP; Yang, J; Sunada, K
刊名	ASTRONOMICAL JOURNAL
	2004-10-01
卷号	128 期号:4 页码:1716-1732
关键词	ISM : clouds ISM : molecules stars : formation
ISSN号	0004-6256
英文摘要	We present results of (CO)-C-13 J = 1-0, (CO)-O-18 J = 1-0, and CS J = 2-1 map observations toward 10 massive star-forming regions selected from the previous CO line survey of cold IRAS sources along the Galactic plane. CS line emission was detected from 9 out of 10 sources, and (CO)-C-13 line emission was detected in all sources. (CO)-O-18 J = 1-0 line emission was detected in only three sources. Physical parameters are derived for the detected sources. The (CO)-C-13 and (CO)-O-18 data support the idea that gradual dissipation of the internal turbulence leads to formation of denser cores and subsequent star formation. There is no apparent relationship between the CS abundance and the CO temperature. The ratios of L-IR to M-LTE vary by no more than a factor of 3 for the CS cores and by nearly 1 order of magnitude for the (CO)-C-13 cores. This indicates that star formation is determined by the gas with high volume density and does not depend on the mass of the cloud. We find that the star formation rate per unit mass is nearly constant in the dense cores. Divided into two subgroups, "low" and "high," by their FIR color indexes, the low sources are in an earlier stage than the high sources, based on the high sources' association with H2O masers.
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]	H-II REGIONS ; ULTRACOMPACT HII-REGIONS ; LUMINOUS IRAS SOURCES ; SOUTHERN H2O MASERS ; STAR-FORMATION ; MOLECULAR CORES ; PROTOSTELLAR CANDIDATES ; CARBON-MONOXIDE ; POINT SOURCES ; CLOUD MASSES
收录类别	SCI
语种	英语
WOS记录号	WOS:000224303400021
公开日期	2012-12-22
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/7697]
专题	紫金山天文台_分子云与恒星形成研究团组
作者单位	1.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China 2.Nobeyama Radio Observ, Minamisa Ku, Nagano 3841305, Japan
推荐引用方式 GB/T 7714	Ao, YP,Yang, J,Sunada, K. (CO)-C-13, (CO)-O-18, and CS observations toward massive dense cores[J]. ASTRONOMICAL JOURNAL,2004,128(4):1716-1732.
APA	Ao, YP,Yang, J,&Sunada, K.(2004).(CO)-C-13, (CO)-O-18, and CS observations toward massive dense cores.ASTRONOMICAL JOURNAL,128(4),1716-1732.
MLA	Ao, YP,et al."(CO)-C-13, (CO)-O-18, and CS observations toward massive dense cores".ASTRONOMICAL JOURNAL 128.4(2004):1716-1732.