A search for hypercompact H II regions in the Galactic Plane

doi:10.1093/mnras/sty2811

CORC > 国家天文台 > 中国科学院国家天文台

	A search for hypercompact H II regions in the Galactic Plane
	Yang, A. Y.1,2,3,4; Thompson, M. A.3; Tian, W. W.1,2,5; Bihr, S.6; Beuther, H.6; Hindson, L.3
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2019
卷号	482 期号:2 页码:2681-2696
关键词	ISM: H II regions infrared: ISM radio continuum: ISM submillimetre: ISM
ISSN号	0035-8711
DOI	10.1093/mnras/sty2811
英文摘要	We have carried out the largest and most unbiased search for hypercompact (HC) H II regions. Our method combines four interferometric radio continuum surveys (THOR, CORNISH, MAGPIS, and White2005) with far-infrared and sub-mm Galactic Plane surveys to identify embedded H II regions with positive spectral indices; 120 positive spectrum H II regions have been identified from a total sample of 534 positive spectral index radio sources. None of these H II regions, including the known HC H II regions recovered in our search, fulfills the canonical definition of an HC H II region at 5 GHz. We suggest that the current canonical definition of HC H II regions is not accurate and should be revised to include a hierarchical structure of ionized gas that results in an extended morphology at 5 GHz. Correlating our search with known ultracompact (UC) H II region surveys, we find that roughly half of detected UC H II regions have positive spectral indices, instead of more commonly assumed flat and optically thin spectra. This implies a mix of optically thin and thick emission and has important implications for previous analyses which have so far assumed optically thin emission for these objects. Positive spectrum H II regions are statistically more luminous and possess higher Lyman continuum fluxes than H II regions with flat or negative indices. Positive spectrum H II regions are thus more likely to be associated with more luminous and massive stars. No differences are found in clump mass, linear diameter, or luminosity-to-mass ratio between positive spectrum and non-positive spectrum H II regions.
资助项目	NSFC[11603039] ; NSFC[11473038] ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant[CSF-648505] ; UK Science & Technology Facilities Council[ST/M001008/1] ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme
WOS关键词	ULTRACOMPACT HII-REGIONS ; STAR-FORMING REGION ; RECOMBINATION LINE ; MASSIVE STARS ; SPECTRAL INDEX ; RADIO ; RESOLUTION ; ACCRETION ; EVOLUTION ; PROTOSTARS
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	OXFORD UNIV PRESS
WOS记录号	WOS:000454578700088
资助机构	NSFC ; NSFC ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant ; UK Science & Technology Facilities Council ; UK Science & Technology Facilities Council ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme ; NSFC ; NSFC ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant ; UK Science & Technology Facilities Council ; UK Science & Technology Facilities Council ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme ; NSFC ; NSFC ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant ; UK Science & Technology Facilities Council ; UK Science & Technology Facilities Council ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme ; NSFC ; NSFC ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant ; European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant ; UK Science & Technology Facilities Council ; UK Science & Technology Facilities Council ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; UK Science & Technology Facilities Council (STFC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme ; China Scholarship Council (CSC) through the China-UK SKA co-training programme
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/24279]
专题	中国科学院国家天文台
通讯作者	Yang, A. Y.; Thompson, M. A.
作者单位	1.Chinese Acad Sci, Key Lab Opt Astron, Natl Astron Observ, Beijing 100012, Peoples R China 2.Univ Chinese Acad Sci, 19A Yuquan Rd, Beijing 100049, Peoples R China 3.Univ Hertfordshire, Sch Phys Astron & Math, Ctr Astrophys Res, Coll Lane, Hatfield AL10 9AB, Herts, England 4.Max Planck Inst Radio Astron, Hugel 69, D-53121 Bonn, Germany 5.Univ Calgary, Dept Phys & Astron, Calgary, AB T1N 1N4, Canada 6.Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany
推荐引用方式 GB/T 7714	Yang, A. Y.,Thompson, M. A.,Tian, W. W.,et al. A search for hypercompact H II regions in the Galactic Plane[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2019,482(2):2681-2696.
APA	Yang, A. Y.,Thompson, M. A.,Tian, W. W.,Bihr, S.,Beuther, H.,&Hindson, L..(2019).A search for hypercompact H II regions in the Galactic Plane.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,482(2),2681-2696.
MLA	Yang, A. Y.,et al."A search for hypercompact H II regions in the Galactic Plane".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 482.2(2019):2681-2696.