Infall motions in massive star-forming regions: results from years 1 and 2 of the MALT90 survey

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 近地天体探测和太阳系天体研究团组

	Infall motions in massive star-forming regions: results from years 1 and 2 of the MALT90 survey
	He, Yu-Xin 1,2; Zhou, Jian-Jun 1,3; Esimbek, Jarken 1,3; Ji, Wei-Guang 1,3; Wu, Gang 1,2,3; Tang, Xin-Di 1,3; Yuan, Ye 1,3; Li, Da-Lei 1,2; Baan, W. A.4,5
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2015-06-21
卷号	450 期号:2 页码:1926-1936
关键词	stars: formation ISM: kinematics and dynamics ISM: molecules radio lines: ISM
英文摘要	Massive star-forming regions with observed infall motions are good sites for studying the birth of massive stars. In this paper, 405 compact sources have been extracted from the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) compact sources that also have been observed in the Millimetre Astronomy Legacy Team 90-GHz (MALT90) survey during years 1 and 2. These observations are complemented with Spitzer GLIMPSE/MIPSGAL mid-IR survey data to help classify the elected star-forming clumps into three evolutionary stages: pre-stellar, proto-stellar and UCHII regions. The results suggest that 0.05 g cm(-2) is a reliable empirical lower bound for the clump surface densities required for massive-star formation to occur. The optically thick HCO+(1-0) and HNC(1-0) lines, as well as the optically thin N2H(+)(1-0) line were used to search for infall motions towards these sources. By analysing the asymmetries of the optically thick HCO+(1-0) and HNC(1-0) lines and the mapping observations of HCO+(1-0), a total of 131 reliable infall candidates have been identified. The HCO+(1-0) line shows the highest occurrence of obvious asymmetric features, suggesting that it may be a better infall motion tracer than other lines such as HNC(1-0). The detection rates of infall candidates towards pre-stellar, proto-stellar and UCHII clumps are 0.3452, 0.3861 and 0.2152, respectively. The relatively high detection rate of infall candidates towards UCHII clumps indicates that many UCHII regions are still accreting matter. The peak column densities and masses of the infall candidates, in general, display an increasing trend with progressing evolutionary stages. However, the rough estimates of the mass infall rate show no obvious variation with evolutionary stage.
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 ; GALACTIC PLANE SURVEY ; RADIO-CONTINUUM ; METHANOL MASERS ; SOURCE CATALOG ; SIZE RELATION ; HII-REGIONS ; EMISSION ; CLOUDS ; CORES
收录类别	SCI
语种	英语
WOS记录号	WOS:000356338500062
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/15999]
专题	紫金山天文台_近地天体探测和太阳系天体研究团组
作者单位	1.Chinese Acad Sci, Xinjiang Astron Observ, Urumqi 830011, Xinjiang, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Chinese Acad Sci, Key Lab Radio Astron, Nanjing 210008, Jiangsu, Peoples R China 4.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 203000, Xuhui, Peoples R China 5.Netherlands Inst Radio Astron, NL-7991 PD Dwingeloo, Netherlands
推荐引用方式 GB/T 7714	He, Yu-Xin,Zhou, Jian-Jun,Esimbek, Jarken,et al. Infall motions in massive star-forming regions: results from years 1 and 2 of the MALT90 survey[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2015,450(2):1926-1936.
APA	He, Yu-Xin.,Zhou, Jian-Jun.,Esimbek, Jarken.,Ji, Wei-Guang.,Wu, Gang.,...&Baan, W. A..(2015).Infall motions in massive star-forming regions: results from years 1 and 2 of the MALT90 survey.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,450(2),1926-1936.
MLA	He, Yu-Xin,et al."Infall motions in massive star-forming regions: results from years 1 and 2 of the MALT90 survey".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 450.2(2015):1926-1936.