VLBI observations of SIO masers around AH Scorpii
文献类型：期刊论文
| 作者 | Chen, Xi ; Shen, Zhi-Qiang
|
| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2008-07-10 |
| 卷号 | 681期号:2页码:1574-1583 |
| 关键词 | circumstellar matter masers stars : individual (AH Sco) stars : kinematics |
| 英文摘要 | We report the first Very Long Baseline Array (VLBA) observations of v = 1, J = 1-0 SiO masers at 43 GHz in the circumstellar envelope of the M-type semiregular supergiant variable star AH Sco at two epochs separated by 12 days in 2004 March. These high-resolution VLBA images reveal that the distribution of the SiO masers is roughly on a persistent elliptical ring, with the lengths of the major and minor axes being about 18.5 and 15.8 mas, respectively, along a position angle of 150 degrees. The redshifted masers are found to be slightly closer to the central star than are the blueshifted masers. The line-of-sight velocity structure of the SiO masers shows that with respect to the systemic velocity of -6.8 km s(-1), the higher velocity features are closer to the star, which can be well explained by the simple outflow or infall, without rotation kinematics, of SiO masers around AH Sco. A study of the proper motions of 59 matched features between our two epochs clearly indicates that the SiO maser shell around AH Sco was undergoing an overall contraction toward the star at a velocity of approximate to 13 km s(-1) at a distance of 2.26 kpc to AH Sco. Our three-dimensional maser kinematics model further suggests that such an inward motion is very likely to be due to the gravitation of the central star. The distance to AH Sco of 2.26 +/- 0.19 kpc that we obtained from our three-dimensional kinematics model fitting is consistent with its kinematic distance of 2.0 kpc. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 学科主题 | 星系与宇宙学研究中心 |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | LATE-TYPE STARS ; MIRA VARIABLE-STARS ; PROPER MOTIONS ; VX-SAGITTARII ; WATER MASERS ; 43 GHZ ; CIRCUMSTELLAR ENVELOPE ; MERLIN OBSERVATIONS ; DUST SHELL ; R-AQUARII |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000257516000062 |
| 公开日期 | 2010-11-08 |
| 源URL | [http://119.78.226.72//handle/331011/12335]  |
| 专题 | 上海天文台_星系宇宙学重点实验室 |
| 作者单位 | Shanghai Astron Observ, Shanghai 200030, Peoples R China |
| 推荐引用方式 GB/T 7714 | Chen, Xi,Shen, Zhi-Qiang. VLBI observations of SIO masers around AH Scorpii[J]. ASTROPHYSICAL JOURNAL,2008,681(2):1574-1583. |
| APA | Chen, Xi,&Shen, Zhi-Qiang.(2008).VLBI observations of SIO masers around AH Scorpii.ASTROPHYSICAL JOURNAL,681(2),1574-1583. |
| MLA | Chen, Xi,et al."VLBI observations of SIO masers around AH Scorpii".ASTROPHYSICAL JOURNAL 681.2(2008):1574-1583. |
入库方式： OAI收割
来源：上海天文台
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