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) 我们对银河系中心的大质量黑洞 SgrA* 周围的几个 SiO 微波激射器进行了 VLBA 观测，我们检测到了其中三个的自行运动，结果表明 SgrA* 可能存在相对运动。我们还发现距离银河系中心2 pc以内的质量下限是2*10^6太阳质量。2）使用野边毫米波干涉仪我们监测了SgrA*短时耀斑的通量密度，在2004年12月至2005年5月的观测期间没有观测到SgrA*的耀斑。3)我们通过分析统计得出了距离银心30 pc以内的质量（包括暗物质）。晚型恒星发射的 SiO 脉泽的视线速度，并使用玻尔兹曼方程沿视线的积分，与 OH 脉泽的分布不同。其中一个 SiO 脉泽遵循距银河系中心距离的平方，假设中心质量是中心黑洞和恒星系统的质量之和，符合平方律，我们可以得出速度动量方程：玻尔兹曼方程的视线积分。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.

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

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.

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.

Study of the Bipolar Nebula IRAS 19312+1950. I. Mapping Observations

双极星云 IRAS 19312 1950 的研究 I. 测绘观测

• 发表时间: 2003
• 期刊: Publications of the Astronomical Society of Japan 56
• 作者: Nakashima;J.;Deguchi;S.;Kuno;N.
• 通讯作者: N.