Origins of Massive Field Stars in the Galactic Center: a Spectroscopic Study
Origins of Massive Field Stars in the Galactic Center: a Spectroscopic Study
复制标题
银河系中心大质量场恒星的起源：光谱研究
DOI：
10.1093/mnras/stu2116
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
A. Cotera
中科院分区：
文献类型：
--
作者：
Hui Dong;J. Mauerhan;M. Morris;Q. Wang;A. Cotera
在银河系中心已知的星星团之外，已经发现了大量演化的大质量恒星，但它们的起源仍然不确定。我们提出了一个光谱研究的八个这样的恒星，基于新的双子座GNIRS和NIFS近红外观测。这项工作导致了一个新的O If+星星的发现。我们比较了我们的恒星与拱门星团中的大质量恒星的变红校正的J-K对K图，并使用恒星演化轨迹来限制它们的年龄和质量。还报道了这两颗恒星及其附近H II区的径向速度。所有的恒星都相对于拱门星团蓝移了> 50 km/s。我们发现我们的源P35具有与周围分子气体一致的速度。沿着Gemini GNIRS长缝附近电离气体相对于P35和邻近的-30-0 km/s分子云的速度梯度可用压力驱动流模型来解释。因此，P35很可能在原位形成。另外三颗恒星的径向速度与邻近的分子气体不同，这表明它们是闯入者。最接近拱星团的四颗恒星与已知的星团成员有着相似的光谱、年龄和质量，这表明它们可能是通过三体相互作用从星团中弹射出来的。因此，我们发现相对孤立的恒星部分是在原地形成的，部分是从银河系中心已知的星星团中被弹射出来的。
Outside of the known star clusters in the Galactic Center, a large number of evolved massive stars have been detected; but their origins remain uncertain. We present a spectroscopic study of eight such stars, based on new Gemini GNIRS and NIFS near-infrared observations. This work has led to the discovery of a new O If+ star. We compare the reddening-corrected J-K vs K diagram for our stars with the massive ones in the Arches cluster and use stellar evolutionary tracks to constrain their ages and masses. The radial velocities of both the stars and their nearby H II regions are also reported. All of the stars are blueshifted relative to the Arches cluster by > 50 km/s. We find that our source P35 has a velocity consistent with that of the surrounding molecular gas. The velocity gradient of nearby ionized gas along the Gemini GNIRS long slit, relative to P35 and the adjacent -30-0 km/s molecular cloud, can best be explained by a pressure-driven flow model. Thus, P35 most likely formed in situ. Three more of our stars have radial velocities different from their adjacent molecular gas, indicating that they are interlopers. The four stars closest to the Arches cluster have similar spectra, ages and masses to known cluster members, suggesting that they were likely ejected from the cluster via three-body interactions. Therefore, we find that the relatively isolated stars partly formed in situ and partly were ejected from the known star clusters in the Galactic Center.
银河系中质量最大的恒星之一可能是孤立形成的
影响因子：
4.8
作者：
L. M. Oskinova;M. Steinke;W.-R. Hamann;A. Sander;H. Todt;A. Liermann
通讯作者：
A. Liermann
五联体星团的轨道运动 拱门和五联体星团的共同起源？
DOI：
10.1088/0004-637x/789/2/115
发表时间：
2014
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Stolte;Hußmann;Morris;Brandner;Clarkson;Habibi;Matthews
通讯作者：
Matthews