A Circumstellar H2O Maser Associated with the Circumnuclear Molecular Disk at the Galactic Center?
A Circumstellar H2O Maser Associated with the Circumnuclear Molecular Disk at the Galactic Center?
复制标题
与银河系中心的环核分子盘相关的环星H2O脉泽？
DOI：
10.1086/309583
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
I. McLean
中科院分区：
文献类型：
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作者：
D. Levine;D. Figer;M. Morris;I. McLean
在对银河系内22 GHz H2O脉泽进行巡天的过程中，我们在银河系西角发现了一个22 GHz H2O脉泽。它位于人马座A * 北纬30 "、东经35"附近，靠近射电小旋圈东臂的边缘，推测与环核盘的内侧边缘重合。此外，脉泽的径向速度是非常相似的，预期在环核盘在这个位置的气体。该脉泽与一颗发光的变红星星重合，该星星具有M超巨星的热星等和红外光谱特征。它的灭绝与银河系内部的一个位置相一致，靠近或位于环核盘内。如果这颗星星是在环核盘内形成的，那么它就是第一个已知的在2pc中央区域最近形成的星星（107 - 108年前），并且可以与它诞生的气体结构相关联。它的形成在这样一个高度剪切和动荡的环境提出了一个挑战，我们的理解有效的星星形成机制。
In the course of conducting a survey of 22 GHz H2O masers in the inner Galaxy, we discovered a maser in Sgr A West. It is located ~30'' N and 35'' E of Sgr A*, near the edge of the eastern arm of the radio minispiral, which presumably coincides with the inside edge of the circumnuclear disk. Furthermore, the radial velocity of the maser is remarkably similar to that expected for gas in the circumnuclear disk at this location. The maser coincides with a luminous, reddened star having a bolometric magnitude and IR spectrum characteristic of an M supergiant. Its extinction is consistent with a location in the inner Galaxy, near or within the circumnuclear disk. If this star formed within the circumnuclear disk, it is the first known case of a recently formed star (107-108 yr ago) in the central 2 pc which can be associated with the gaseous structure in which it was born. Its formation in such a highly sheared and turbulent environment presents a challenge to our understanding of effective star formation mechanisms.