HIGH-RESOLUTION VLBA OBSERVATIONS OF THREE 7 mm SiO MASERS TOWARD VX Sgr AT FIVE EPOCHS

	HIGH-RESOLUTION VLBA OBSERVATIONS OF THREE 7 mm SiO MASERS TOWARD VX Sgr AT FIVE EPOCHS
	Su, J. B.1,2,3; Shen, Z. -Q.1,2; Chen, X.1,2 ; Yi, Jiyune 4; Jiang, D. R.1,2; Yun, Y. J.5
刊名	ASTROPHYSICAL JOURNAL
	2012-07-20
卷号	754 期号:1 页码:1
关键词	masers stars: individual (VX Sgr) supergiants techniques: interferometric
英文摘要	VX Sgr is a red supergiant at an adopted distance of 1.6 kpc with intense 43 GHz SiO maser emission. In this paper, we present the high-resolution very long baseline interferometry (VLBI) observations of SiO masers toward VX Sgr at five epochs. We used the Very Long Baseline Array to map the J = 1 -> 0 (upsilon = 1, 2) (SiO)-Si-28 masers and confirmed a ring-like structure. In the first two epochs, the upsilon = 1 masers form a ring, but upsilon = 2 maser spots residing only in the southern and northern regions do not form a complete ring. In the third epoch, the two masers are distributed in a ring structure and the upsilon = 2 masers are a bit closer to the central star. In the last two epochs, many new maser spots appear and overlap each other. These overlapping maser spots can be related to the shock waves and reflect the collisional pumping. We compare the observations with the pumping models and speculate that the real pumping mechanism may be complex in VX Sgr and vary with time. The J = 1 -> 0 (upsilon = 0) (SiO)-Si-29 line emission is also detected, but is too weak to produce any VLBI map.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	EVOLVED STARS ; TX CAM ; 43 GHZ ; SAGITTARII ; VARIABILITY ; EMISSION ; V=1
收录类别	SCI
语种	英语
WOS记录号	WOS:000306111800047
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/18109]
专题	上海天文台_星系宇宙学重点实验室
作者单位	1.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 2.Chinese Acad Sci, Key Lab Radio Astron, Nanjing, Jiangsu, Peoples R China 3.Chinese Acad Sci, Grad Sch, Beijing 100034, Peoples R China 4.Korea Astron & Space Sci Inst, Taejon 305348, South Korea 5.Seoul Natl Univ, Dept Phys & Astron, Seoul, South Korea
推荐引用方式 GB/T 7714	Su, J. B.,Shen, Z. -Q.,Chen, X.,et al. HIGH-RESOLUTION VLBA OBSERVATIONS OF THREE 7 mm SiO MASERS TOWARD VX Sgr AT FIVE EPOCHS[J]. ASTROPHYSICAL JOURNAL,2012,754(1):1.
APA	Su, J. B.,Shen, Z. -Q.,Chen, X.,Yi, Jiyune,Jiang, D. R.,&Yun, Y. J..(2012).HIGH-RESOLUTION VLBA OBSERVATIONS OF THREE 7 mm SiO MASERS TOWARD VX Sgr AT FIVE EPOCHS.ASTROPHYSICAL JOURNAL,754(1),1.
MLA	Su, J. B.,et al."HIGH-RESOLUTION VLBA OBSERVATIONS OF THREE 7 mm SiO MASERS TOWARD VX Sgr AT FIVE EPOCHS".ASTROPHYSICAL JOURNAL 754.1(2012):1.