The interplay between star formation and the nuclear environment of our Galaxy: deep X-ray observations of the Galactic centre Arches and Quintuplet clusters
The interplay between star formation and the nuclear environment of our Galaxy: deep X-ray observations of the Galactic centre Arches and Quintuplet clusters
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恒星形成与银河系核环境之间的相互作用：银河系中心拱门和五联体星团的深度 X 射线观测
DOI：
10.1111/j.1365-2966.2006.10656.x
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发表时间：
2006
影响因子：
4.8
通讯作者：
C. Lang
中科院分区：
文献类型：
--
作者：
Daniel Wang;Hui Dong;C. Lang
银河中心（GC）提供了一个独特的实验室，用于详细检查大质量恒星形成与银河系核环境之间的相互作用。在这里，我们展示了 100 ks 钱德拉高级 CCD 成像光谱仪 (ACIS) 对拱门和五重星团的观测。我们还报告了用欧文斯谷毫米波阵列制作的拱门星团附近致密分子气体的补充测绘。我们提供了在观测中检测到的 244 个点状 X 射线源的目录。它们的数量-通量关系表明相对明亮的 X 射线源数量过多，这显然与星团有关。拱门和五重星团核心的来源很可能是极端碰撞的风大双星。来自拱门星团核心的漫射 X 射线发射光谱显示 6.7 keV 发射线和随半径急剧下降的表面强度分布，表明星团风的起源。在拱门星团附近的外部区域，整体漫射 X 射线增强表现出弓形激波形态，并且在等效宽度约为 1.4 keV 的 Fe Kα 6.4-keV 线发射中很突出。这种增强很大程度上可能是由于团簇和相邻分子云之间正在进行的碰撞造成的，它们具有相对速度？ 120公里-1。较古老且不太致密的五重星团包含较弱的 X 射线源和漫射发射，可能源自低质量恒星物体以及星团风。然而，如果这些天体具有正常的米勒和斯卡洛初始质量函数，则受观测到的总漫射 X 射线光度的限制，这些天体的总体数量远小于两个星团的预期。这种低质量天体的不足可能是GC独特的恒星形成环境的体现，其中频繁发生高速云与云和云与星团碰撞。
The Galactic centre (GC) provides a unique laboratory for a detailed examination of the interplay between massive star formation and the nuclear environment of our Galaxy. Here, we present a 100-ks Chandra Advanced CCD Imaging Spectrometer (ACIS) observation of the Arches and Quintuplet star clusters. We also report on a complementary mapping of the dense molecular gas near the Arches cluster made with the Owens Valley Millimeter Array. We present a catalogue of 244 point-like X-ray sources detected in the observation. Their number-flux relation indicates an overpopulation of relatively bright X-ray sources, which are apparently associated with the clusters. The sources in the core of the Arches and Quintuplet clusters are most likely extreme colliding wind massive star binaries. The diffuse X-ray emission from the core of the Arches cluster has a spectrum showing a 6.7-keV emission line and a surface intensity profile declining steeply with radius, indicating an origin in a cluster wind. In the outer regions near the Arches cluster, the overall diffuse X-ray enhancement demonstrates a bow shock morphology and is prominent in the Fe Kα 6.4-keV line emission with an equivalent width of ∼ 1.4 keV. Much of this enhancement may result from an ongoing collision between the cluster and the adjacent molecular cloud, which have a relative velocity? 120 km -1 . The older and less-compact Quintuplet cluster contains much weaker X-ray sources and diffuse emission, probably originating from low-mass stellar objects as well as a cluster wind. However, the overall population of these objects, constrained by the observed total diffuse X-ray luminosities, is substantially smaller than expected for both clusters, if they have normal Miller & Scalo initial mass functions. This deficiency of low-mass objects may be a manifestation of the unique star formation environment of the GC, where high-velocity cloud-cloud and cloud-cluster collisions are frequent.