Observational Study of the Massive Black Hole SgrA* and its Surrounding Field

巨大黑洞SgrA*及其周围场的观测研究

• 批准号: 15540242
• 负责人: MIYOSHI Makoto
• 金额: $ 1.98万
• 依托单位: National Astronomical Observatory Japan, NIH
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540242/
• 关键词: Galactic Center; Black Hole; mass distributions; SiO masers; delta VLBI; SgrA*; 一酸化珪素メーザ; 巨大ブラックホール; 固有運動; 中心質量; 銀河系中心

1) We performed VLBA observations of several SiO masers around the massive black hole, SgrA* at the Galactic center. We detected proper motions of the three out of them with accuracy about 0.1mas/year. The results suggest that SgrA* may move relative to the surrounding stars. We also found the lower limit of the mass within 2 pc from the Galactic center is 2*10^6 solar mass.2) Using the Nobeyama Millimeter wave Interferometer we monitored the flux density of SgrA* for short time flaring. There observed no flare of SgrA* within the observing session from Dec 2004 to May 2005.3) We derived the mass (including dark matter) within 30 pc from the Galactic center by analyzing the statistics of line of sight velocities of SiO maser emissions from late type stars and by the use of integration of the Bolzmann equation along the line of sight. Unlike the distribution of OH masers, the one of the SiO masers follows the square of the distance from the Galactic center. Assuming that the central mass is the sum of the mass of central black hole and stellar system with the square law, we can make an equation of momentum of velocities from the line of sight integration of Bolzmann equation.The mass of the Galactic center is M R=(2.69±1.30]+0.88[±0.07](R/pc)^{1.25)×10^6 solar mass.

1)我们对银河系中心大质量黑洞SgrA*周围的几个SiO脉泽进行了VLBA观测。我们以大约0.1mas/年的精度检测了其中三个的固有运动。结果表明SgrA*可能会相对于周围的恒星移动。我们还发现，距离银河系中心2 pc内的质量下限是2*10^6个太阳质量。2)利用Nobeyama毫米波干涉仪监测了SgrA*短时间耀斑的通量密度。在2004年12月至2005年5月的观测期间，没有观测到SgrA*的耀斑。5.3)我们通过分析晚型恒星发射的SiO脉泽的视线速度统计数据，并利用沿视线方向的玻尔兹曼方程的积分，得出了银河系中心30 pc内的质量（包括暗物质）。与OH脉泽的分布不同，SiO脉泽的分布遵循与银河系中心距离的平方。假设中心质量为中心黑洞质量和恒星系统质量的平方定律之和，我们可以从玻尔兹曼方程的视线积分得到速度动量方程。银河系中心的质量为M R=（2.69±1.30)+0.88[±0.07](R/pc)^{1.25）×10^6太阳质量。

项目成果

SiO Maser Survey toward the Inner Galactic Disk : 40 deg <1<70 deg and |b|<10 deg

朝向内银河盘的 SiO 脉泽巡天：40 度 <1<70 度且 |b|<10 度

• 发表时间: 2003
• 期刊: Publications of the Astronomical Society of Japan 55
• 作者: Nakashima;J.;Deguchi;S.
• 通讯作者: S.

VLBA observation of a radio intraday flare of Sgr A*

VLBA 观测 Sgr A* 的射电日间耀斑

• 发表时间: 2003
• 期刊: Astronomische Nachrichten, Supplementary Issue 324
• 作者: Miyoshi;M.;Imai;H.;Nakashima;J.;Deguchi;S.;Shen;Z.-Q.
• 通讯作者: Z.-Q.

SiO Maser Survey of Cold IRAS Sources

• DOI: 10.1093/pasj/55.1.229
• 发表时间: 2003-01
• 期刊: Publications of the Astronomical Society of Japan
• 影响因子: 2.3
• 作者: J. Nakashima;S. Deguchi

Searching for Structural Variability in Sgr A

• DOI: 10.1002/asna.200385090
• 发表时间: 2003-09
• 期刊: Astronomische Nachrichten
• 影响因子: 0.9
• 作者: Zhi-qiang Shen;M. Liang;K. Lo;M. Miyoshi

Study of the Bipolar Nebula IRAS 19312+1950. II. Circumstellar Chemistry

双极星云的研究 IRAS 19312 1950。 II．

• 发表时间: 2004
• 期刊: Publications of the Astronomical Society of Japan 56
• 作者: Deguchi;S.;Nakashima;J.;Takano;S.
• 通讯作者: S.