AGE SPREAD IN W3 MAIN: LARGE BINOCULAR TELESCOPE/LUCI NEAR-INFRARED SPECTROSCOPY OF THE MASSIVE STELLAR CONTENT

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	AGE SPREAD IN W3 MAIN: LARGE BINOCULAR TELESCOPE/LUCI NEAR-INFRARED SPECTROSCOPY OF THE MASSIVE STELLAR CONTENT
	Bik, A.1; Henning, Th.1; Stolte, A.2; Brandner, W.1; Gouliermis, D. A.1; Gennaro, M.1; Pasquali, A.3; Rochau, B.1; Beuther, H.1; Ageorges, N.4
刊名	ASTROPHYSICAL JOURNAL
	2012-01-10
卷号	744 期号:2 页码:87(13pp)
关键词	H II regions infrared: stars stars: formation stars: massive techniques: spectroscopic
ISSN号	0004-637X
英文摘要	We present near-infrared multi-object spectroscopy and JHK(s) imaging of the massive stellar content of the Galactic star-forming region W3 Main, obtained with LUCI at the Large Binocular Telescope. We confirm 15 OB stars in W3 Main and derive spectral types between O5V and B4V from their absorption line spectra. Three massive young stellar objects are identified by their emission line spectra and near-infrared excess. The color-color diagram of the detected sources allows a detailed investigation of the slope of the near-infrared extinction law toward W3 Main. Analysis of the Hertzsprung-Russell diagram suggests that the Nishiyama extinction law fits the stellar population of W3 Main best (E(J -H)/ E(H - K-s) = 1.76 and RKs = 1.44). From our spectrophotometric analysis of the massive stars and the nature of their surrounding H II regions, we derive the evolutionary sequence of W3 Main and we find evidence of an age spread of at least 2-3 Myr. While the most massive star (IRS2) is already evolved, indications for high-mass pre-main-sequence evolution are found for another star (IRS N1), deeply embedded in an ultracompact H II (UCH II) region, in line with the different evolutionary phases observed in the corresponding H II regions. We derive a stellar mass of W3 Main of (4 +/- 1) x 10(3) M-circle dot by extrapolating from the number of OB stars using a Kroupa initial mass function and correcting for our spectroscopic incompleteness. We have detected the photospheres of OB stars from the more evolved diffuse H II region to the much younger UCH II regions, suggesting that these stars have finished their formation and cleared away their circumstellar disks very fast. Only in the hyper-compact H II region (IRS5) do the early-type stars seem to be still surrounded by circumstellar material.
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 REGION ; INTERSTELLAR EXTINCTION LAW ; GIANT MOLECULAR CLOUD ; STAR-FORMING REGIONS ; K-BAND SPECTROSCOPY ; PERSEUS SPIRAL ARM ; GALACTIC-O-STARS ; 8.0 MU-M ; ORION NEBULA ; HII-REGIONS
收录类别	SCI
语种	英语
WOS记录号	WOS:000298666400007
公开日期	2013-01-31
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/8092]
专题	紫金山天文台_宇宙伽马暴、中子星及相关物理研究团组
作者单位	1.Max Planck Inst Astron, D-69117 Heidelberg, Germany 2.Argelander Inst Astron, D-53121 Bonn, Germany 3.Heidelberg Univ, Astron Rech Inst, D-69120 Heidelberg, Germany 4.Max Planck Inst Extraterr Phys, D-85748 Garching, Germany 5.Heidelberg Univ, Zentrum Astron Heidelberg, Landessternwarte Konigstuhl, D-69117 Heidelberg, Germany 6.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Bik, A.,Henning, Th.,Stolte, A.,et al. AGE SPREAD IN W3 MAIN: LARGE BINOCULAR TELESCOPE/LUCI NEAR-INFRARED SPECTROSCOPY OF THE MASSIVE STELLAR CONTENT[J]. ASTROPHYSICAL JOURNAL,2012,744(2):87(13pp).
APA	Bik, A..,Henning, Th..,Stolte, A..,Brandner, W..,Gouliermis, D. A..,...&Kudryavtseva, N..(2012).AGE SPREAD IN W3 MAIN: LARGE BINOCULAR TELESCOPE/LUCI NEAR-INFRARED SPECTROSCOPY OF THE MASSIVE STELLAR CONTENT.ASTROPHYSICAL JOURNAL,744(2),87(13pp).
MLA	Bik, A.,et al."AGE SPREAD IN W3 MAIN: LARGE BINOCULAR TELESCOPE/LUCI NEAR-INFRARED SPECTROSCOPY OF THE MASSIVE STELLAR CONTENT".ASTROPHYSICAL JOURNAL 744.2(2012):87(13pp).