Discovery of Hot Supergiant Stars near the Galactic Center
Discovery of Hot Supergiant Stars near the Galactic Center
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在银河系中心附近发现热超巨星
DOI：
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发表时间：
2007
期刊：
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通讯作者：
M. Morris
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作者：
J. Mauerhan;M. Muno;M. Morris
我们报告了在银河系中心寻找沃尔夫拉叶星和 O (WR/O) 恒星以及高质量 X 射线双星 (HMXB) 活动的新结果。我们通过将两微米全天巡天与射电拱门区域的深度钱德拉 X 射线天文台点源目录进行交叉关联来寻找候选者。通过 K 波段光谱，我们发现了 CXOGC J174555.3-285126 和 CXOGC J174617.0-285131 的两颗大质量恒星，我们分别将其分类为 WN6b 亚型的宽线 WR 星和 O Ia 超巨星。它们的X射线特性与银河系和大麦哲伦星云中已知的碰撞风双星的X射线特性最为一致，尽管也有可能出现低速率吸积到致密天体上的情况。 O Ia 星在五重星团投影中的位置为 4.4 pc，其径向速度与五重星团一致，表明这颗恒星可能已经逃离了五重星团。我们还发现了一颗 B2 Ia 超巨星，我们使用已知大质量 X 射线发射恒星 CXOGC J174516.1-290315 附近区域的银河系中心 8 μm 斯皮策图将其识别为候选大质量恒星。我们在银河中心不断演化的星团的背景下讨论这些恒星的起源。
We report new results of a campaign to find Wolf-Rayet and O (WR/O) stars and high-mass X-ray binaries (HMXBs) in the Galactic center. We searched for candidates by cross-correlating the Two Micron All Sky Survey with a deep Chandra X-Ray Observatory catalog of point sources in the Radio Arches region. Following up with K-band spectroscopy, we found two massive stellar counterparts to CXOGC J174555.3-285126 and CXOGC J174617.0-285131, which we classify as a broad-lined WR star of subtype WN6b and an O Ia supergiant, respectively. Their X-ray properties are most consistent with those of known colliding-wind binaries in the Galaxy and the Large Magellanic Cloud, although a scenario involving low-rate accretion onto a compact object is also possible. The O Ia star lies 4.4 pc in projection from the Quintuplet cluster and has a radial velocity consistent with that of the Quintuplet, suggesting that this star might have escaped from the cluster. We also present the discovery of a B2 Ia supergiant, which we identified as a candidate massive star using 8 μm Spitzer maps of the Galactic center in a region near the known massive X-ray-emitting star CXOGC J174516.1-290315. We discuss the origin of these stars in the context of evolving stellar clusters in the Galactic center.