Observational Study of the SiO Maser Sources at the Galactic Center Region

银河系中心区域 SiO 脉泽源的观测研究

• 批准号: 10640238
• 负责人: DEGUCHI Shuji
• 金额: $ 1.92万
• 依托单位: National Astronomical Observatory
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640238/
• 关键词: Masers; Galaxy; Galactic rotation; Bulge; Bar structure; SiO; 銀河中心; ブラックホール; 赤外線源; 周期-光度関係

This research explores the physics in the environment near the galactic center with measuring the radial velocities of stars in the silicon monoxide (SiO) maser lines from late type stars by a radio telescope. We have completed the following radio and infrared observations in Hl0 and H11 academic years. (1) 600 color-selected IRAS sources in the galactic disk have been observed in SiO maser lines with the 45-m radio telescope at Nobeyama., resulting 300 detection. From analyzing the obtained radial velocities of stars, we found a group of the stars being deviant from the galactic rotation which was known from the gas motion. (2) We made the JHK photometric and imaging observations for about 500 sources in the same region with the Australian National Univ. 2.3-m infrared telescope. From the apparent magnitudes, we estimated the distances to the objects.From this research, the following facts are revealed. (1) large percentages of IRAS sources which are located within 10 degree from the galactic center are considered to be the bulge stars. A subset of stars located in front of the galactic center exhibits a large negative (-46 km/s) average radial velocity, and those behind, a positive radial velocity,. Here the distance were deduced from the infrared intensities at 12 and 25 micron. (3) This phenomenon is interpreted as a streaming motion of stars in the bar-like bulge; the near end of the bar is located at the first quadrant of the galactic longitude and the stellar orbits are elongated along the bar potential. Dr. S. Deguchi planned and directed the research and analyzed the near-infrared photometric data. Dr. Miyoshi analyzed the radio spectral data and performed the VLBI observations.

本研究利用射电望远镜测量晚型恒星的一氧化硅脉泽谱线中恒星的径向速度，探讨银心附近环境的物理。我们在H10和H11学年完成了下列射电和红外观测。(1)用野边山45米射电望远镜观测了银盘上600个色选IRAS源的SiO脉泽谱线。得到300检测。通过分析获得的恒星径向速度，我们发现一组恒星偏离了从气体运动中已知的银河系自转。(2)我们用澳大利亚国立大学的2.3米红外望远镜对同一地区的约500个源进行了JHK测光和成像观测。根据视星等，我们估计了到天体的距离。(1)大部分位于银河系中心10度以内的IRAS源被认为是核球星。位于银河系中心前面的恒星子集表现出较大的负径向速度（-46 km/s），而后面的恒星则表现出正径向速度。这里，距离是从12微米和25微米处的红外强度推导出的。(3)这种现象被解释为恒星在棒状隆起中的流动运动;棒状隆起的近端位于银经的第一象限，恒星轨道沿棒状势沿着拉长。Dr. S.出口计划并指导了研究，并分析了近红外光度数据。Miyoshi博士分析了无线电光谱数据并进行了VLBI观测。

项目成果

Jiang, B. W., Deguchi, S., 他: "SiO Masers in stars in the Inner and Outer Galactic Disk"Publication of Astronomical Society of Japan. 51. 95-102 (1999)

Jiang, B. W., Deguchi, S., et al.：“银河系内外恒星中的 SiO Masers”，日本天文学会出版 51. 95-102 (1999)。

Hermstein,J.R.A et al.: "VLBA Continuum Observations of NGC 4258: Constraints on an Advection-dominated Accretion Flow" Astrophysical Journal. 497. L69-L73 (1998)

Hermstein, J.R.A 等人：“NGC 4258 的 VLBA 连续观测：对平流主导吸积流的约束”天体物理学杂志。

Jang, B.W., Deguchi, S., 他: "SiO Masters in the Inner and Outer Galactic Disk"Pablication of Astronomical society of Japan. 51. 95-102 (1999)

Jang, B.W., Deguchi, S., et al.：“SiO Masters in the Inner and Outer Gactic Disk”日本天文学会出版 51. 95-102 (1999)。

Deguchi,S.,et al.: "Near Infrared Observations of IRAS Sources with SiO Masers in the Direction of the Near End of the Galactic Bar" Publication of Astronomical Society of Japan. 50. 507-610 (1998)

Deguchi,S.,et al.：“Near Infrared Observations of IRAS Sources with SiO Masers in the Direction of the Near End of the Gactic Bar” 日本天文学会出版物。

Jiang,B.W.,et al.: "SiO Masers in stars in the Inner and Outer Galactic Disk" Publication of Astronomical Society of Japan. 51. 95-102 (1999)

蒋B.W.等：《内外银盘恒星中的SiO脉泽》，日本天文学会刊物。