THE DAWNING OF THE STREAM OF AQUARIUS IN RAVE
THE DAWNING OF THE STREAM OF AQUARIUS IN RAVE
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DOI：
10.1088/0004-637x/728/2/102
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发表时间：
2010-12
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影响因子：
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通讯作者：
Mary E. K. Williams;M. Steinmetz;Sanjib Sharma;J. Bland-Hawthorn;R. D. Jong;G. Seabroke;A. Helmi;K. Freeman;J. Binney;I. Minchev;O. Bienaym'e;R. Campbell;J. Fulbright;B. Gibson;G. Gilmore;E. Grebel;U. Munari;J. Navarro;Q. Parker;W. Reid;A. Siebert;A. Siviero;F. Watson;R. Wyse;T. Zwitter
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文献类型：
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作者：
Mary E. K. Williams;M. Steinmetz;Sanjib Sharma;J. Bland-Hawthorn;R. D. Jong;G. Seabroke;A. Helmi;K. Freeman;J. Binney;I. Minchev;O. Bienaym'e;R. Campbell;J. Fulbright;B. Gibson;G. Gilmore;E. Grebel;U. Munari;J. Navarro;Q. Parker;W. Reid;A. Siebert;A. Siviero;F. Watson;R. Wyse;T. Zwitter
我们确定了一个新的，附近的（0.5kpc × 10 kpc）流的数据从RAVE（RAVE）。由于溪流中的大多数恒星位于宝瓶座，我们将其命名为宝瓶座溪流。我们确定了15个位于30° < l < 75°和−70° < B < −50°之间的流成员，日心视线速度Vlos −200 km s−1。这些成员是径向速度分布中的异常值，与贝桑松星系模型和新开发的代码Galaxia创建的模拟样本相比，密度过大具有统计学意义。金属丰度分布函数和log g-Teff平面中的等时线拟合表明，该流由10 Gyr年龄的人口组成，[M/H] −1.0。我们探索与其他流和子结构的关系，发现流不能与已知的结构识别：它是一个新的，附近的子结构在银河系的晕。使用一个简单的动力学模型的溶解卫星星系，我们占本地化的流。我们发现，该流是动态年轻，因此可能是最近破裂的矮星系或球状星团的碎片。因此，宝瓶座流是正在进行的星系分层形成的标本，在太阳郊区是罕见的。
We identify a new, nearby (0.5kpc ≲ d ≲ 10 kpc) stream in data from the RAdial Velocity Experiment (RAVE). As the majority of stars in the stream lie in the constellation of Aquarius, we name it the Aquarius Stream. We identify 15 members of the stream lying between 30° < l < 75° and −70° < b < −50°, with heliocentric line-of-sight velocities Vlos ∼ −200 km s−1. The members are outliers in the radial velocity distribution, and the overdensity is statistically significant when compared to mock samples created with both the Besançon Galaxy model and newly developed code Galaxia. The metallicity distribution function and isochrone fit in the log g–Teff plane suggest that the stream consists of a 10 Gyr old population with [M/H] ∼ −1.0. We explore relations to other streams and substructures, finding that the stream cannot be identified with known structures: it is a new, nearby substructure in the Galaxy's halo. Using a simple dynamical model of a dissolving satellite galaxy, we account for the localization of the stream. We find that the stream is dynamically young and therefore likely the debris of a recently disrupted dwarf galaxy or globular cluster. The Aquarius stream is thus a specimen of ongoing hierarchical Galaxy formation, rare for being right in the solar suburb.