On the identification of merger debris in the Gaia era
On the identification of merger debris in the Gaia era
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DOI：
10.1111/j.1365-2966.2010.17225.x
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发表时间：
2010-04
影响因子：
4.8
通讯作者：
F. G'omez;A. Helmi;Anthony G. A. Brown;Yang-Shyang Li
中科院分区：
文献类型：
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作者：
F. G'omez;A. Helmi;Anthony G. A. Brown;Yang-Shyang Li
我们模拟银河系恒星晕的形成，通过吸积的卫星星系上的时间依赖的半宇宙星系势。我们的目标是以接近盖亚使命可能的方式来表征这些吸积事件留下的子结构。我们已经创建了一个合成的盖亚太阳邻域目录，通过将我们被破坏的卫星的恒星粒子的六维相空间坐标与盖亚测量误差的最新估计进行卷积，并包括由于银河系盘和凸起而造成的现实背景污染。我们发现，即使在考虑了预期的观测误差后，所得的相空间也充满了子结构。我们能够成功地隔离大约50%的不同的卫星，有助于“太阳邻居”，通过在能量角动量空间中应用均值漂移聚类算法。此外，对轨道频率空间的傅里叶分析使我们能够对大约30%的回收卫星的吸积时间作出准确的估计。
We model the formation of the Galactic stellar halo via the accretion of satellite galaxies on to a time-dependent semicosmological galactic potential. Our goal is to characterize the substructure left by these accretion events in a close manner to what may be possible with the Gaia mission. We have created a synthetic Gaia solar neighbourhood catalogue by convolving the six-dimensional phase-space coordinates of stellar particles from our disrupted satellites with the latest estimates of the Gaia measurement errors, and included realistic background contamination due to the Galactic disc(s) and bulge. We find that, even after accounting for the expected observational errors, the resulting phase space is full of substructure. We are able to successfully isolate roughly 50 per cent of the different satellites contributing to the 'solar neighbourhood' by applying the mean shift clustering algorithm in energy-angular momentum space. Furthermore, a Fourier analysis of the space of orbital frequencies allows us to obtain accurate estimates of the time since accretion for approximately 30 per cent of the recovered satellites.