A Varying Mass-to-Light Ratio in the Galactic Center Cluster?
A Varying Mass-to-Light Ratio in the Galactic Center Cluster?
复制标题
银河系中心星团的质光比发生变化？
DOI：
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复制
发表时间：
1996
期刊：
影响因子：
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通讯作者：
P. Mcgregor
中科院分区：
文献类型：
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作者：
P. Saha;G. Bicknell;P. Mcgregor
我们重新分析发表的运动学和光度数据的冷星星人口在中央10 pc（240弧秒）的银河系，而（a）隔离光度数据适合这个人口，和（B）适当地允许投影效果。在假设系统是球形各向同性的情况下，我们发现M/L_K在0.35pc处从2开始变化。我们认为，这种变化的M/L_K可能是由于越来越多的恒星残骸向银河系中心集中。我们推导出的质量-半径曲线证实了在银河系中心0.35 pc范围内存在~3x10^6 M_sol，在0.2 pc范围内存在~1.5x10^6 M_sol。然而，后者的估计是受不确定的冷星在该地区的分布。我们还考虑了靠近银河系中心的热星星种群的动力学，并表明He I恒星的速度色散和热恒星的表面亮度分布与从冷恒星推断的质量分布是一致的。
We reanalyze published kinematic and photometric data for the cool star population in the central 10 pc (240 arcsec) of the Galaxy, while (a) isolating the photometric data appropriate to this population, and (b) properly allowing for projection effects. Under the assumptions that the system is spherical and isotropic, we find that M/L_K varies from 2 at 0.35 pc. We suggest that such a varying M/L_K could be due to an increasing concentration of stellar remnants towards the Galactic center. Our derived mass-radius curve confirms the existence of ~3x10^6 M_sol within 0.35 pc of the Galactic Center, and ~1.5x10^6 M_sol with 0.2 pc. However, the latter estimate is subject to the uncertain distribution of cool stars in the region. We also consider the dynamics of the hot star population close to the Galactic center and show that the velocity dispersion of He I stars and the surface brightness distribution of the hot stars are consistent with the mass distribution inferred from cool stars.