Observations of 6.7 GHz methanol masers with East-Asian VLBI Network. I. VLBI images of the first epoch of observations

	Observations of 6.7 GHz methanol masers with East-Asian VLBI Network. I. VLBI images of the first epoch of observations
	Fujisawa, Kenta 1,2; Sugiyama, Koichiro 2; Motogi, Kazuhito 2; Hachisuka, Kazuya 3; Yonekura, Yoshinori 4; Sawada-Satoh, Satoko 5; Matsumoto, Naoko 6; Sorai, Kazuo 7; Momose, Munetake 8; Saito, Yu 8
刊名	PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
	2014-04-01
卷号	66 期号:2
关键词	H II regions instrumentation: high angular resolution masers stars: formation
英文摘要	Very-long-baseline interferometry (VLBI) monitoring of the 6.7 GHz methanol maser allows us to measure the internal proper motion of maser spots and therefore study the gas motion around high-mass young stellar objects. To this end, we have begun monitoring observations with the East-Asian VLBI Network. In this paper we present the results of the first epoch observation for 36 sources, including 35 VLBI images of the methanol maser. Since two independent sources were found in three images, images of 38 sources were obtained. In 34 sources, 10 or more spots were detected. The observed spatial scale of the maser distribution was from 9 to 4900 astronomical units, and the following morphological categories were observed: elliptical, arched, linear, paired, and complex. The position of the maser spot was determined with an accuracy of approximately 0.1 mas, which is sufficiently high to measure the internal proper motion from two years of monitoring observations. The VLBI observation, however, detected only approximately 20% of all maser emissions, suggesting that the remaining 80% of the total flux was spread into an undetectable extended distribution. Therefore, in addition to high-resolution observations, it is important to observe the whole structure of the maser emission including extended low-brightness structures, in order to reveal the associated site of the maser and gas motion.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	STAR-FORMING REGIONS ; H-II REGIONS ; ULTRACOMPACT HII-REGIONS ; YOUNG STELLAR OBJECTS ; INFRARED DARK CLOUDS ; 3 KPC ARM ; TRIGONOMETRIC PARALLAXES ; HIGH-RESOLUTION ; OUTFLOW SIGNATURES ; CIRCUMSTELLAR DISC
收录类别	SCI
语种	英语
WOS记录号	WOS:000339427200016
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/15594]
专题	紫金山天文台_盱眙天文观测站
作者单位	1.Yamaguchi Univ, Res Inst Time Studies, Yamaguchi 7538511, Japan 2.Yamaguchi Univ, Grad Sch Sci & Engn, Yamaguchi 7538511, Japan 3.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 4.Ibaraki Univ, Ctr Astron, Mito, Ibaraki 3108512, Japan 5.Natl Astron Observ Japan, Mizusawa VLBI Observ, Mizusawa Ku, Oshu, Iwate 0230861, Japan 6.Natl Astron Observ Japan, Mizusawa VLBI Observ, Mitaka, Tokyo 1818588, Japan 7.Hokkaido Univ, Dept Cosmosci, Dept Phys, Kita Ku, Sapporo, Hokkaido 0600810, Japan 8.Ibaraki Univ, Coll Sci, Mito, Ibaraki 3108512, Japan 9.Gifu Univ, Fac Engn, Gifu 5011193, Japan 10.Osaka Prefecture Univ, Dept Phys Sci, Naka Ku, Sakai, Osaka 5998531, Japan
推荐引用方式 GB/T 7714	Fujisawa, Kenta,Sugiyama, Koichiro,Motogi, Kazuhito,et al. Observations of 6.7 GHz methanol masers with East-Asian VLBI Network. I. VLBI images of the first epoch of observations[J]. PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN,2014,66(2).
APA	Fujisawa, Kenta.,Sugiyama, Koichiro.,Motogi, Kazuhito.,Hachisuka, Kazuya.,Yonekura, Yoshinori.,...&Kim, Kee-Tae.(2014).Observations of 6.7 GHz methanol masers with East-Asian VLBI Network. I. VLBI images of the first epoch of observations.PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN,66(2).
MLA	Fujisawa, Kenta,et al."Observations of 6.7 GHz methanol masers with East-Asian VLBI Network. I. VLBI images of the first epoch of observations".PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN 66.2(2014).